Merge remote-tracking branch 'remotes/origin/DRTVWR-563' into DRTVWR-559

105 files changed, 2041 insertions, 4484 deletions

diff --git a/indra/llappearance/lltexlayerparams.cpp b/indra/llappearance/lltexlayerparams.cpp
index ce5c7142d5..06b4f6c75a 100644
--- a/indra/llappearance/lltexlayerparams.cpp
+++ b/indra/llappearance/lltexlayerparams.cpp
@@ -151,7 +151,7 @@ LLTexLayerParamAlpha::LLTexLayerParamAlpha(const LLTexLayerParamAlpha& pOther)
 	mCachedProcessedTexture(pOther.mCachedProcessedTexture),
 	mStaticImageTGA(pOther.mStaticImageTGA),
 	mStaticImageRaw(pOther.mStaticImageRaw),
-	mNeedsCreateTexture(pOther.mNeedsCreateTexture),
+	mNeedsCreateTexture(pOther.mNeedsCreateTexture.load()),
 	mStaticImageInvalid(pOther.mStaticImageInvalid),
 	mAvgDistortionVec(pOther.mAvgDistortionVec),
 	mCachedEffectiveWeight(pOther.mCachedEffectiveWeight)
diff --git a/indra/llappearance/lltexlayerparams.h b/indra/llappearance/lltexlayerparams.h
index e2440998b3..000f55685e 100644
--- a/indra/llappearance/lltexlayerparams.h
+++ b/indra/llappearance/lltexlayerparams.h
@@ -100,7 +100,7 @@ private:
 	LLPointer<LLGLTexture>	mCachedProcessedTexture;
 	LLPointer<LLImageTGA>	mStaticImageTGA;
 	LLPointer<LLImageRaw>	mStaticImageRaw;
-	BOOL					mNeedsCreateTexture;
+	std::atomic<BOOL>		mNeedsCreateTexture;
 	BOOL					mStaticImageInvalid;
 	LL_ALIGN_16(LLVector4a				mAvgDistortionVec);
 	F32						mCachedEffectiveWeight;
diff --git a/indra/llcommon/CMakeLists.txt b/indra/llcommon/CMakeLists.txt
index 59aa731af2..62307c6e26 100644
--- a/indra/llcommon/CMakeLists.txt
+++ b/indra/llcommon/CMakeLists.txt
@@ -29,6 +29,7 @@ include_directories(
 #     ${LLCOMMON_LIBRARIES})
 
 set(llcommon_SOURCE_FILES
+    commoncontrol.cpp
     indra_constants.cpp
     llallocator.cpp
     llallocator_heap_profile.cpp
@@ -130,6 +131,7 @@ set(llcommon_HEADER_FILES
 
     chrono.h
     classic_callback.h
+    commoncontrol.h
     ctype_workaround.h
     fix_macros.h
     indra_constants.h
diff --git a/indra/llcommon/commoncontrol.cpp b/indra/llcommon/commoncontrol.cpp
new file mode 100644
index 0000000000..81e66baf8c
--- /dev/null
+++ b/indra/llcommon/commoncontrol.cpp
@@ -0,0 +1,106 @@
+/**
+ * @file   commoncontrol.cpp
+ * @author Nat Goodspeed
+ * @date   2022-06-08
+ * @brief  Implementation for commoncontrol.
+ * 
+ * $LicenseInfo:firstyear=2022&license=viewerlgpl$
+ * Copyright (c) 2022, Linden Research, Inc.
+ * $/LicenseInfo$
+ */
+
+// Precompiled header
+#include "linden_common.h"
+// associated header
+#include "commoncontrol.h"
+// STL headers
+// std headers
+// external library headers
+// other Linden headers
+#include "llevents.h"
+#include "llsdutil.h"
+
+LLSD LL::CommonControl::access(const LLSD& params)
+{
+    // We can't actually introduce a link-time dependency on llxml, or on any
+    // global LLControlGroup (*koff* gSavedSettings *koff*) but we can issue a
+    // runtime query. If we're running as part of a viewer with
+    // LLViewerControlListener, we can use that to interact with any
+    // instantiated LLControGroup.
+    LLSD response;
+    {
+        LLEventStream reply("reply");
+        LLTempBoundListener connection = reply.listen("listener",
+                     [&response] (const LLSD& event)
+                     {
+                         response = event;
+                         return false;
+                     });
+        LLSD rparams{ params };
+        rparams["reply"] = reply.getName();
+        LLEventPumps::instance().obtain("LLViewerControl").post(rparams);
+    }
+    // LLViewerControlListener responds immediately. If it's listening at all,
+    // it will already have set response.
+    if (! response.isDefined())
+    {
+        LLTHROW(NoListener("No LLViewerControl listener instantiated"));
+    }
+    LLSD error{ response["error"] };
+    if (error.isDefined())
+    {
+        LLTHROW(ParamError(error));
+    }
+    response.erase("error");
+    response.erase("reqid");
+    return response;
+}
+
+/// set control group.key to defined default value
+LLSD LL::CommonControl::set_default(const std::string& group, const std::string& key)
+{
+    return access(llsd::map("op", "set",
+                            "group", group, "key", key))["value"];
+}
+
+/// set control group.key to specified value
+LLSD LL::CommonControl::set(const std::string& group, const std::string& key, const LLSD& value)
+{
+    return access(llsd::map("op", "set",
+                            "group", group, "key", key, "value", value))["value"];
+}
+
+/// toggle boolean control group.key
+LLSD LL::CommonControl::toggle(const std::string& group, const std::string& key)
+{
+    return access(llsd::map("op", "toggle",
+                            "group", group, "key", key))["value"];
+}
+
+/// get the definition for control group.key, (! isDefined()) if bad
+/// ["name"], ["type"], ["value"], ["comment"]
+LLSD LL::CommonControl::get_def(const std::string& group, const std::string& key)
+{
+    return access(llsd::map("op", "get",
+                            "group", group, "key", key));
+}
+
+/// get the value of control group.key
+LLSD LL::CommonControl::get(const std::string& group, const std::string& key)
+{
+    return access(llsd::map("op", "get",
+                            "group", group, "key", key))["value"];
+}
+
+/// get defined groups
+std::vector<std::string> LL::CommonControl::get_groups()
+{
+    auto groups{ access(llsd::map("op", "groups"))["groups"] };
+    return { groups.beginArray(), groups.endArray() };
+}
+
+/// get definitions for all variables in group
+LLSD LL::CommonControl::get_vars(const std::string& group)
+{
+    return access(llsd::map("op", "vars", "group", group))["vars"];
+}
diff --git a/indra/llcommon/commoncontrol.h b/indra/llcommon/commoncontrol.h
new file mode 100644
index 0000000000..07d4a45ac5
--- /dev/null
+++ b/indra/llcommon/commoncontrol.h
@@ -0,0 +1,75 @@
+/**
+ * @file   commoncontrol.h
+ * @author Nat Goodspeed
+ * @date   2022-06-08
+ * @brief  Access LLViewerControl LLEventAPI, if process has one.
+ * 
+ * $LicenseInfo:firstyear=2022&license=viewerlgpl$
+ * Copyright (c) 2022, Linden Research, Inc.
+ * $/LicenseInfo$
+ */
+
+#if ! defined(LL_COMMONCONTROL_H)
+#define LL_COMMONCONTROL_H
+
+#include <vector>
+#include "llexception.h"
+#include "llsd.h"
+
+namespace LL
+{
+    class CommonControl
+    {
+    public:
+        struct Error: public LLException
+        {
+            Error(const std::string& what): LLException(what) {}
+        };
+
+        /// Exception thrown if there's no LLViewerControl LLEventAPI
+        struct NoListener: public Error
+        {
+            NoListener(const std::string& what): Error(what) {}
+        };
+
+        struct ParamError: public Error
+        {
+            ParamError(const std::string& what): Error(what) {}
+        };
+
+        /// set control group.key to defined default value
+        static
+        LLSD set_default(const std::string& group, const std::string& key);
+
+        /// set control group.key to specified value
+        static
+        LLSD set(const std::string& group, const std::string& key, const LLSD& value);
+
+        /// toggle boolean control group.key
+        static
+        LLSD toggle(const std::string& group, const std::string& key);
+
+        /// get the definition for control group.key, (! isDefined()) if bad
+        /// ["name"], ["type"], ["value"], ["comment"]
+        static
+        LLSD get_def(const std::string& group, const std::string& key);
+
+        /// get the value of control group.key
+        static
+        LLSD get(const std::string& group, const std::string& key);
+
+        /// get defined groups
+        static
+        std::vector<std::string> get_groups();
+
+        /// get definitions for all variables in group
+        static
+        LLSD get_vars(const std::string& group);
+
+    private:
+        static
+        LLSD access(const LLSD& params);
+    };
+} // namespace LL
+
+#endif /* ! defined(LL_COMMONCONTROL_H) */
diff --git a/indra/llcommon/llapr.cpp b/indra/llcommon/llapr.cpp
index db94765871..b537102510 100644
--- a/indra/llcommon/llapr.cpp
+++ b/indra/llcommon/llapr.cpp
@@ -526,6 +526,7 @@ S32 LLAPRFile::seek(apr_file_t* file_handle, apr_seek_where_t where, S32 offset)
 //static
 S32 LLAPRFile::readEx(const std::string& filename, void *buf, S32 offset, S32 nbytes, LLVolatileAPRPool* pool)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	//*****************************************
 	LLAPRFilePoolScope scope(pool);
 	apr_file_t* file_handle = open(filename, scope.getVolatileAPRPool(), APR_READ|APR_BINARY); 
@@ -570,6 +571,7 @@ S32 LLAPRFile::readEx(const std::string& filename, void *buf, S32 offset, S32 nb
 //static
 S32 LLAPRFile::writeEx(const std::string& filename, void *buf, S32 offset, S32 nbytes, LLVolatileAPRPool* pool)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	apr_int32_t flags = APR_CREATE|APR_WRITE|APR_BINARY;
 	if (offset < 0)
 	{
diff --git a/indra/llcommon/llframetimer.cpp b/indra/llcommon/llframetimer.cpp
index 58af32f1af..1e9920746b 100644
--- a/indra/llcommon/llframetimer.cpp
+++ b/indra/llcommon/llframetimer.cpp
@@ -29,11 +29,6 @@
 
 #include "llframetimer.h"
 
-// We don't bother building a stand alone lib; we just need to include the one source file for Tracy support
-//#if LL_PROFILER_CONFIGURATION == LL_PROFILER_CONFIG_TRACY || LL_PROFILER_CONFIGURATION == LL_PROFILER_CONFIG_TRACY_FAST_TIMER
-//	#include "TracyClient.cpp"
-//#endif // LL_PROFILER_CONFIGURATION
-
 // Static members
 //LLTimer	LLFrameTimer::sInternalTimer;
 U64 LLFrameTimer::sStartTotalTime = totalTime();
diff --git a/indra/llcommon/llmemory.cpp b/indra/llcommon/llmemory.cpp
index 849867586a..749b66b472 100644
--- a/indra/llcommon/llmemory.cpp
+++ b/indra/llcommon/llmemory.cpp
@@ -35,6 +35,7 @@
 # include <sys/types.h>
 # include <mach/task.h>
 # include <mach/mach_init.h>
+#include <mach/mach_host.h>
 #elif LL_LINUX
 # include <unistd.h>
 #endif
@@ -109,6 +110,50 @@ void LLMemory::updateMemoryInfo()
 	{
 		sAvailPhysicalMemInKB = U32Kilobytes(0);
 	}
+
+#elif defined(LL_DARWIN)
+    task_vm_info info;
+    mach_msg_type_number_t  infoCount = TASK_VM_INFO_COUNT;
+    // MACH_TASK_BASIC_INFO reports the same resident_size, but does not tell us the reusable bytes or phys_footprint.
+    if (task_info(mach_task_self(), TASK_VM_INFO, reinterpret_cast<task_info_t>(&info), &infoCount) == KERN_SUCCESS)
+    {
+        // Our Windows definition of PagefileUsage is documented by Microsoft as "the total amount of
+        // memory that the memory manager has committed for a running process", which is rss.
+        sAllocatedPageSizeInKB = U32Bytes(info.resident_size);
+
+        // Activity Monitor => Inspect Process => Real Memory Size appears to report resident_size
+        // Activity monitor => main window memory column appears to report phys_footprint, which spot checks as at least 30% less.
+        //        I think that is because of compression, which isn't going to give us a consistent measurement. We want uncompressed totals.
+        //
+        // In between is resident_size - reusable. This is what Chrome source code uses, with source comments saying it is 'the "Real Memory" value
+        // reported for the app by the Memory Monitor in Instruments.' It is still about 8% bigger than phys_footprint.
+        //
+        // (On Windows, we use WorkingSetSize.)
+        sAllocatedMemInKB = U32Bytes(info.resident_size - info.reusable);
+     }
+    else
+    {
+        LL_WARNS() << "task_info failed" << LL_ENDL;
+    }
+
+    // Total installed and available physical memory are properties of the host, not just our process.
+    vm_statistics64_data_t vmstat;
+    mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
+    mach_port_t host = mach_host_self();
+    vm_size_t page_size;
+    host_page_size(host, &page_size);
+    kern_return_t result = host_statistics64(host, HOST_VM_INFO64, reinterpret_cast<host_info_t>(&vmstat), &count);
+    if (result == KERN_SUCCESS) {
+        // This is what Chrome reports as 'the "Physical Memory Free" value reported by the Memory Monitor in Instruments.'
+        // Note though that inactive pages are not included here and not yet free, but could become so under memory pressure.
+        sAvailPhysicalMemInKB = U32Bytes(vmstat.free_count * page_size);
+        sMaxPhysicalMemInKB = LLMemoryInfo::getHardwareMemSize();
+      }
+    else
+    {
+        LL_WARNS() << "task_info failed" << LL_ENDL;
+    }
+
 #else
 	//not valid for other systems for now.
 	sAllocatedMemInKB = U64Bytes(LLMemory::getCurrentRSS());
diff --git a/indra/llcommon/llprofiler.h b/indra/llcommon/llprofiler.h
index bc46128d21..c0f5868db3 100644
--- a/indra/llcommon/llprofiler.h
+++ b/indra/llcommon/llprofiler.h
@@ -134,6 +134,10 @@ extern thread_local bool gProfilerEnabled;
         #define LL_PROFILE_ZONE_ERR(name)               LL_PROFILE_ZONE_NAMED_COLOR( name, 0XFF0000  )  // RGB yellow
         #define LL_PROFILE_ZONE_INFO(name)              LL_PROFILE_ZONE_NAMED_COLOR( name, 0X00FFFF  )  // RGB cyan
         #define LL_PROFILE_ZONE_WARN(name)              LL_PROFILE_ZONE_NAMED_COLOR( name, 0x0FFFF00 )  // RGB red
+        //#define LL_PROFILE_ALLOC(ptr, size)             TracyAlloc(ptr, size) // memory allocation tracking currently not working
+        //#define LL_PROFILE_FREE(ptr)                    TracyFree(ptr)
+        #define LL_PROFILE_ALLOC(ptr, size)             (void)(ptr); (void)(size);
+        #define LL_PROFILE_FREE(ptr)                    (void)(ptr);
     #endif
 #else
     #define LL_PROFILER_FRAME_END
diff --git a/indra/llcommon/llqueuedthread.cpp b/indra/llcommon/llqueuedthread.cpp
index 8cef4293cd..155e32ebae 100644
--- a/indra/llcommon/llqueuedthread.cpp
+++ b/indra/llcommon/llqueuedthread.cpp
@@ -26,20 +26,26 @@
 #include "linden_common.h"
 #include "llqueuedthread.h"
 
+#include <chrono>
+
 #include "llstl.h"
 #include "lltimer.h"	// ms_sleep()
-#include "lltracethreadrecorder.h"
+#include "llmutex.h"
 
 //============================================================================
 
 // MAIN THREAD
 LLQueuedThread::LLQueuedThread(const std::string& name, bool threaded, bool should_pause) :
-	LLThread(name),
-	mThreaded(threaded),
-	mIdleThread(TRUE),
-	mNextHandle(0),
-	mStarted(FALSE)
+    LLThread(name),
+    mIdleThread(TRUE),
+    mNextHandle(0),
+    mStarted(FALSE),
+    mThreaded(threaded),
+    mRequestQueue(name, 1024 * 1024)
 {
+    llassert(threaded); // not threaded implementation is deprecated
+    mMainQueue = LL::WorkQueue::getInstance("mainloop");
+
 	if (mThreaded)
 	{
 		if(should_pause)
@@ -69,6 +75,11 @@ void LLQueuedThread::shutdown()
 	unpause(); // MAIN THREAD
 	if (mThreaded)
 	{
+        if (mRequestQueue.size() == 0)
+        {
+            mRequestQueue.close();
+        }
+
 		S32 timeout = 100;
 		for ( ; timeout>0; timeout--)
 		{
@@ -104,6 +115,8 @@ void LLQueuedThread::shutdown()
 	{
 		LL_WARNS() << "~LLQueuedThread() called with active requests: " << active_count << LL_ENDL;
 	}
+
+    mRequestQueue.close();
 }
 
 //----------------------------------------------------------------------------
@@ -112,6 +125,7 @@ void LLQueuedThread::shutdown()
 // virtual
 S32 LLQueuedThread::update(F32 max_time_ms)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	if (!mStarted)
 	{
 		if (!mThreaded)
@@ -125,29 +139,34 @@ S32 LLQueuedThread::update(F32 max_time_ms)
 
 S32 LLQueuedThread::updateQueue(F32 max_time_ms)
 {
-	F64 max_time = (F64)max_time_ms * .001;
-	LLTimer timer;
-	S32 pending = 1;
-
+    LL_PROFILE_ZONE_SCOPED;
 	// Frame Update
 	if (mThreaded)
 	{
-		pending = getPending();
-		if(pending > 0)
+        // schedule a call to threadedUpdate for every call to updateQueue
+        if (!isQuitting())
+        {
+            mRequestQueue.post([=]()
+                {
+                    LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("qt - update");
+                    mIdleThread = FALSE;
+                    threadedUpdate();
+                    mIdleThread = TRUE;
+                }
+            );
+        }
+
+		if(getPending() > 0)
 		{
-		unpause();
-	}
+		    unpause();
+	    }
 	}
 	else
 	{
-		while (pending > 0)
-		{
-			pending = processNextRequest();
-			if (max_time && timer.getElapsedTimeF64() > max_time)
-				break;
-		}
+        mRequestQueue.runFor(std::chrono::microseconds((int) (max_time_ms*1000.f)));
+        threadedUpdate();
 	}
-	return pending;
+	return getPending();
 }
 
 void LLQueuedThread::incQueue()
@@ -166,11 +185,7 @@ void LLQueuedThread::incQueue()
 // May be called from any thread
 S32 LLQueuedThread::getPending()
 {
-	S32 res;
-	lockData();
-	res = mRequestQueue.size();
-	unlockData();
-	return res;
+	return mRequestQueue.size();
 }
 
 // MAIN thread
@@ -195,35 +210,28 @@ void LLQueuedThread::waitOnPending()
 // MAIN thread
 void LLQueuedThread::printQueueStats()
 {
-	lockData();
-	if (!mRequestQueue.empty())
+    U32 size = mRequestQueue.size();
+	if (size > 0)
 	{
-		QueuedRequest *req = *mRequestQueue.begin();
-		LL_INFOS() << llformat("Pending Requests:%d Current status:%d", mRequestQueue.size(), req->getStatus()) << LL_ENDL;
+		LL_INFOS() << llformat("Pending Requests:%d ", mRequestQueue.size()) << LL_ENDL;
 	}
 	else
 	{
 		LL_INFOS() << "Queued Thread Idle" << LL_ENDL;
 	}
-	unlockData();
 }
 
 // MAIN thread
 LLQueuedThread::handle_t LLQueuedThread::generateHandle()
 {
-	lockData();
-	while ((mNextHandle == nullHandle()) || (mRequestHash.find(mNextHandle)))
-	{
-		mNextHandle++;
-	}
-	const LLQueuedThread::handle_t res = mNextHandle++;
-	unlockData();
+    U32 res = ++mNextHandle;
 	return res;
 }
 
 // MAIN thread
 bool LLQueuedThread::addRequest(QueuedRequest* req)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	if (mStatus == QUITTING)
 	{
 		return false;
@@ -231,14 +239,14 @@ bool LLQueuedThread::addRequest(QueuedRequest* req)
 	
 	lockData();
 	req->setStatus(STATUS_QUEUED);
-	mRequestQueue.insert(req);
-	mRequestHash.insert(req);
+    mRequestHash.insert(req);
 #if _DEBUG
 // 	LL_INFOS() << llformat("LLQueuedThread::Added req [%08d]",handle) << LL_ENDL;
 #endif
 	unlockData();
 
-	incQueue();
+    llassert(!mDataLock->isSelfLocked());
+    mRequestQueue.post([this, req]() { processRequest(req); });
 
 	return true;
 }
@@ -246,6 +254,7 @@ bool LLQueuedThread::addRequest(QueuedRequest* req)
 // MAIN thread
 bool LLQueuedThread::waitForResult(LLQueuedThread::handle_t handle, bool auto_complete)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	llassert (handle != nullHandle());
 	bool res = false;
 	bool waspaused = isPaused();
@@ -312,6 +321,7 @@ LLQueuedThread::status_t LLQueuedThread::getRequestStatus(handle_t handle)
 
 void LLQueuedThread::abortRequest(handle_t handle, bool autocomplete)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_THREAD;
 	lockData();
 	QueuedRequest* req = (QueuedRequest*)mRequestHash.find(handle);
 	if (req)
@@ -333,30 +343,9 @@ void LLQueuedThread::setFlags(handle_t handle, U32 flags)
 	unlockData();
 }
 
-void LLQueuedThread::setPriority(handle_t handle, U32 priority)
-{
-	lockData();
-	QueuedRequest* req = (QueuedRequest*)mRequestHash.find(handle);
-	if (req)
-	{
-		if(req->getStatus() == STATUS_INPROGRESS)
-		{
-			// not in list
-			req->setPriority(priority);
-		}
-		else if(req->getStatus() == STATUS_QUEUED)
-		{
-			// remove from list then re-insert
-			llverify(mRequestQueue.erase(req) == 1);
-			req->setPriority(priority);
-			mRequestQueue.insert(req);
-		}
-	}
-	unlockData();
-}
-
 bool LLQueuedThread::completeRequest(handle_t handle)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	bool res = false;
 	lockData();
 	QueuedRequest* req = (QueuedRequest*)mRequestHash.find(handle);
@@ -399,89 +388,115 @@ bool LLQueuedThread::check()
 //============================================================================
 // Runs on its OWN thread
 
-S32 LLQueuedThread::processNextRequest()
+void LLQueuedThread::processRequest(LLQueuedThread::QueuedRequest* req)
 {
-	QueuedRequest *req;
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_THREAD;
+
+    mIdleThread = FALSE;
+    //threadedUpdate();
+
 	// Get next request from pool
 	lockData();
 	
-	while(1)
+	if ((req->getFlags() & FLAG_ABORT) || (mStatus == QUITTING))
 	{
-		req = NULL;
-		if (mRequestQueue.empty())
+        LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("qtpr - abort");
+		req->setStatus(STATUS_ABORTED);
+		req->finishRequest(false);
+		if (req->getFlags() & FLAG_AUTO_COMPLETE)
 		{
-			break;
-		}
-		req = *mRequestQueue.begin();
-		mRequestQueue.erase(mRequestQueue.begin());
-		if ((req->getFlags() & FLAG_ABORT) || (mStatus == QUITTING))
-		{
-			req->setStatus(STATUS_ABORTED);
-			req->finishRequest(false);
-			if (req->getFlags() & FLAG_AUTO_COMPLETE)
-			{
-				mRequestHash.erase(req);
-				req->deleteRequest();
-// 				check();
-			}
-			continue;
-		}
-		llassert_always(req->getStatus() == STATUS_QUEUED);
-		break;
-	}
-	U32 start_priority = 0 ;
-	if (req)
-	{
-		req->setStatus(STATUS_INPROGRESS);
-		start_priority = req->getPriority();
-	}
-	unlockData();
-
-	// This is the only place we will call req->setStatus() after
-	// it has initially been seet to STATUS_QUEUED, so it is
-	// safe to access req.
-	if (req)
-	{
-		// process request		
-		bool complete = req->processRequest();
-
-		if (complete)
-		{
-			lockData();
-			req->setStatus(STATUS_COMPLETE);
-			req->finishRequest(true);
-			if (req->getFlags() & FLAG_AUTO_COMPLETE)
-			{
-				mRequestHash.erase(req);
-				req->deleteRequest();
+			mRequestHash.erase(req);
+			req->deleteRequest();
 // 				check();
-			}
-			unlockData();
 		}
-		else
-		{
-			lockData();
-			req->setStatus(STATUS_QUEUED);
-			mRequestQueue.insert(req);
-			unlockData();
-			if (mThreaded && start_priority < PRIORITY_NORMAL)
-			{
-				ms_sleep(1); // sleep the thread a little
-			}
-		}
-		
-		LLTrace::get_thread_recorder()->pushToParent();
+        unlockData();
 	}
+    else
+    {
+        llassert_always(req->getStatus() == STATUS_QUEUED);
+
+        if (req)
+        {
+            req->setStatus(STATUS_INPROGRESS);
+        }
+        unlockData();
+
+        // This is the only place we will call req->setStatus() after
+        // it has initially been seet to STATUS_QUEUED, so it is
+        // safe to access req.
+        if (req)
+        {
+            // process request		
+            bool complete = req->processRequest();
+
+            if (complete)
+            {
+                LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("qtpr - complete");
+                lockData();
+                req->setStatus(STATUS_COMPLETE);
+                req->finishRequest(true);
+                if (req->getFlags() & FLAG_AUTO_COMPLETE)
+                {
+                    mRequestHash.erase(req);
+                    req->deleteRequest();
+                    // 				check();
+                }
+                unlockData();
+            }
+            else
+            {
+                LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("qtpr - retry");
+                //put back on queue and try again in 0.1ms
+                lockData();
+                req->setStatus(STATUS_QUEUED);
+                
+                unlockData();
+
+                llassert(!mDataLock->isSelfLocked());
+
+#if 0
+                // try again on next frame
+                // NOTE: tried using "post" with a time in the future, but this
+                // would invariably cause this thread to wait for a long time (10+ ms)
+                // while work is pending
+                bool ret = LL::WorkQueue::postMaybe(
+                    mMainQueue,
+                    [=]()
+                    {
+                        LL_PROFILE_ZONE_NAMED("processRequest - retry");
+                        mRequestQueue.post([=]()
+                            {
+                                LL_PROFILE_ZONE_NAMED("processRequest - retry"); // <-- not redundant, track retry on both queues
+                                processRequest(req);
+                            });
+                    });
+                llassert(ret);
+#else
+                using namespace std::chrono_literals;
+                auto retry_time = LL::WorkQueue::TimePoint::clock::now() + 16ms;
+                mRequestQueue.post([=]
+                    {
+                        LL_PROFILE_ZONE_NAMED("processRequest - retry");
+                        while (LL::WorkQueue::TimePoint::clock::now() < retry_time)
+                        {
+                            std::this_thread::yield(); //note: don't use LLThread::yield here to avoid 
+                        }
+                        processRequest(req);
+                    });
+#endif
+                
+            }
+        }
+    }
 
-	S32 pending = getPending();
-	return pending;
+    mIdleThread = TRUE;
 }
 
 // virtual
 bool LLQueuedThread::runCondition()
 {
 	// mRunCondition must be locked here
-	if (mRequestQueue.empty() && mIdleThread)
+	if (mRequestQueue.size() == 0 && mIdleThread)
 		return false;
 	else
 		return true;
@@ -495,18 +510,13 @@ void LLQueuedThread::run()
 	startThread();
 	mStarted = TRUE;
 	
-	while (1)
+
+	/*while (1)
 	{
+        LL_PROFILE_ZONE_SCOPED;
 		// this will block on the condition until runCondition() returns true, the thread is unpaused, or the thread leaves the RUNNING state.
 		checkPause();
 		
-		if (isQuitting())
-		{
-			LLTrace::get_thread_recorder()->pushToParent();
-			endThread();
-			break;
-		}
-
 		mIdleThread = FALSE;
 
 		threadedUpdate();
@@ -515,12 +525,18 @@ void LLQueuedThread::run()
 
 		if (pending_work == 0)
 		{
+            //LL_PROFILE_ZONE_NAMED("LLQueuedThread - sleep");
 			mIdleThread = TRUE;
-			ms_sleep(1);
+			//ms_sleep(1);
 		}
 		//LLThread::yield(); // thread should yield after each request		
-	}
+	}*/
+    mRequestQueue.runUntilClose();
+
+    endThread();
 	LL_INFOS() << "LLQueuedThread " << mName << " EXITING." << LL_ENDL;
+
+    
 }
 
 // virtual
@@ -540,10 +556,9 @@ void LLQueuedThread::threadedUpdate()
 
 //============================================================================
 
-LLQueuedThread::QueuedRequest::QueuedRequest(LLQueuedThread::handle_t handle, U32 priority, U32 flags) :
+LLQueuedThread::QueuedRequest::QueuedRequest(LLQueuedThread::handle_t handle, U32 flags) :
 	LLSimpleHashEntry<LLQueuedThread::handle_t>(handle),
 	mStatus(STATUS_UNKNOWN),
-	mPriority(priority),
 	mFlags(flags)
 {
 }
diff --git a/indra/llcommon/llqueuedthread.h b/indra/llcommon/llqueuedthread.h
index 5d3f873646..6b82ccc434 100644
--- a/indra/llcommon/llqueuedthread.h
+++ b/indra/llcommon/llqueuedthread.h
@@ -36,6 +36,7 @@
 
 #include "llthread.h"
 #include "llsimplehash.h"
+#include "workqueue.h"
 
 //============================================================================
 // Note: ~LLQueuedThread is O(N) N=# of queued threads, assumed to be small
@@ -45,15 +46,6 @@ class LL_COMMON_API LLQueuedThread : public LLThread
 {
 	//------------------------------------------------------------------------
 public:
-	enum priority_t {
-		PRIORITY_IMMEDIATE = 0x7FFFFFFF,
-		PRIORITY_URGENT =    0x40000000,
-		PRIORITY_HIGH =      0x30000000,
-		PRIORITY_NORMAL =    0x20000000,
-		PRIORITY_LOW =       0x10000000,
-		PRIORITY_LOWBITS =   0x0FFFFFFF,
-		PRIORITY_HIGHBITS =  0x70000000
-	};
 	enum status_t {
 		STATUS_EXPIRED = -1,
 		STATUS_UNKNOWN = 0,
@@ -82,28 +74,17 @@ public:
 		virtual ~QueuedRequest(); // use deleteRequest()
 		
 	public:
-		QueuedRequest(handle_t handle, U32 priority, U32 flags = 0);
+		QueuedRequest(handle_t handle, U32 flags = 0);
 
 		status_t getStatus()
 		{
 			return mStatus;
 		}
-		U32 getPriority() const
-		{
-			return mPriority;
-		}
 		U32 getFlags() const
 		{
 			return mFlags;
 		}
-		bool higherPriority(const QueuedRequest& second) const
-		{
-			if ( mPriority == second.mPriority)
-				return mHashKey < second.mHashKey;
-			else
-				return mPriority > second.mPriority;
-		}
-
+		
 	protected:
 		status_t setStatus(status_t newstatus)
 		{
@@ -121,28 +102,11 @@ public:
 		virtual void finishRequest(bool completed); // Always called from thread after request has completed or aborted
 		virtual void deleteRequest(); // Only method to delete a request
 
-		void setPriority(U32 pri)
-		{
-			// Only do this on a request that is not in a queued list!
-			mPriority = pri;
-		};
-		
 	protected:
 		LLAtomicBase<status_t> mStatus;
-		U32 mPriority;
 		U32 mFlags;
 	};
 
-protected:
-	struct queued_request_less
-	{
-		bool operator()(const QueuedRequest* lhs, const QueuedRequest* rhs) const
-		{
-			return lhs->higherPriority(*rhs); // higher priority in front of queue (set)
-		}
-	};
-
-
 	//------------------------------------------------------------------------
 	
 public:
@@ -167,7 +131,7 @@ private:
 protected:
 	handle_t generateHandle();
 	bool addRequest(QueuedRequest* req);
-	S32  processNextRequest(void);
+	void processRequest(QueuedRequest* req);
 	void incQueue();
 
 public:
@@ -186,7 +150,6 @@ public:
 	status_t getRequestStatus(handle_t handle);
 	void abortRequest(handle_t handle, bool autocomplete);
 	void setFlags(handle_t handle, U32 flags);
-	void setPriority(handle_t handle, U32 priority);
 	bool completeRequest(handle_t handle);
 	// This is public for support classes like LLWorkerThread,
 	// but generally the methods above should be used.
@@ -200,8 +163,10 @@ protected:
 	BOOL mStarted;  // required when mThreaded is false to call startThread() from update()
 	LLAtomicBool mIdleThread; // request queue is empty (or we are quitting) and the thread is idle
 	
-	typedef std::set<QueuedRequest*, queued_request_less> request_queue_t;
-	request_queue_t mRequestQueue;
+	//typedef std::set<QueuedRequest*, queued_request_less> request_queue_t;
+	//request_queue_t mRequestQueue;
+    LL::WorkQueue mRequestQueue;
+    LL::WorkQueue::weak_t mMainQueue;
 
 	enum { REQUEST_HASH_SIZE = 512 }; // must be power of 2
 	typedef LLSimpleHash<handle_t, REQUEST_HASH_SIZE> request_hash_t;
diff --git a/indra/llcommon/llsys.cpp b/indra/llcommon/llsys.cpp
index 9b6bb3826c..45417bfa37 100644
--- a/indra/llcommon/llsys.cpp
+++ b/indra/llcommon/llsys.cpp
@@ -710,20 +710,28 @@ static U32Kilobytes LLMemoryAdjustKBResult(U32Kilobytes inKB)
 }
 #endif
 
+#if LL_DARWIN
+// static
+U32Kilobytes LLMemoryInfo::getHardwareMemSize()
+{
+    // This might work on Linux as well.  Someone check...
+    uint64_t phys = 0;
+    int mib[2] = { CTL_HW, HW_MEMSIZE };
+
+    size_t len = sizeof(phys);
+    sysctl(mib, 2, &phys, &len, NULL, 0);
+
+    return U64Bytes(phys);
+}
+#endif
+
 U32Kilobytes LLMemoryInfo::getPhysicalMemoryKB() const
 {
 #if LL_WINDOWS
 	return LLMemoryAdjustKBResult(U32Kilobytes(mStatsMap["Total Physical KB"].asInteger()));
 
 #elif LL_DARWIN
-	// This might work on Linux as well.  Someone check...
-	uint64_t phys = 0;
-	int mib[2] = { CTL_HW, HW_MEMSIZE };
-
-	size_t len = sizeof(phys);	
-	sysctl(mib, 2, &phys, &len, NULL, 0);
-	
-	return U64Bytes(phys);
+    return getHardwareMemSize();
 
 #elif LL_LINUX
 	U64 phys = 0;
diff --git a/indra/llcommon/llsys.h b/indra/llcommon/llsys.h
index cb92cb0ac6..538e61c521 100644
--- a/indra/llcommon/llsys.h
+++ b/indra/llcommon/llsys.h
@@ -117,7 +117,10 @@ public:
 	LLMemoryInfo(); ///< Default constructor
 	void stream(std::ostream& s) const;	///< output text info to s
 
-	U32Kilobytes getPhysicalMemoryKB() const; 
+	U32Kilobytes getPhysicalMemoryKB() const;
+#if LL_DARWIN
+    static U32Kilobytes getHardwareMemSize(); // Because some Mac linkers won't let us reference extern gSysMemory from a different lib.
+#endif
 
 	//get the available memory infomation in KiloBytes.
 	static void getAvailableMemoryKB(U32Kilobytes& avail_physical_mem_kb, U32Kilobytes& avail_virtual_mem_kb);
diff --git a/indra/llcommon/lltimer.cpp b/indra/llcommon/lltimer.cpp
index aaa6df325c..39dfee3755 100644
--- a/indra/llcommon/lltimer.cpp
+++ b/indra/llcommon/lltimer.cpp
@@ -30,6 +30,9 @@
 
 #include "u64.h"
 
+#include <chrono>
+#include <thread>
+
 #if LL_WINDOWS
 #	include "llwin32headerslean.h"
 #elif LL_LINUX || LL_DARWIN
@@ -64,7 +67,13 @@ LLTimer* LLTimer::sTimer = NULL;
 #if LL_WINDOWS
 void ms_sleep(U32 ms)
 {
-	Sleep(ms);
+    LL_PROFILE_ZONE_SCOPED;
+    using TimePoint = std::chrono::steady_clock::time_point;
+    auto resume_time = TimePoint::clock::now() + std::chrono::milliseconds(ms);
+    while (TimePoint::clock::now() < resume_time)
+    {
+        std::this_thread::yield(); //note: don't use LLThread::yield here to avoid yielding for too long
+    }
 }
 
 U32 micro_sleep(U64 us, U32 max_yields)
diff --git a/indra/llcommon/llworkerthread.cpp b/indra/llcommon/llworkerthread.cpp
index 4b91b2caca..02ce4823b8 100644
--- a/indra/llcommon/llworkerthread.cpp
+++ b/indra/llcommon/llworkerthread.cpp
@@ -133,11 +133,11 @@ S32 LLWorkerThread::update(F32 max_time_ms)
 
 //----------------------------------------------------------------------------
 
-LLWorkerThread::handle_t LLWorkerThread::addWorkRequest(LLWorkerClass* workerclass, S32 param, U32 priority)
+LLWorkerThread::handle_t LLWorkerThread::addWorkRequest(LLWorkerClass* workerclass, S32 param)
 {
 	handle_t handle = generateHandle();
 	
-	WorkRequest* req = new WorkRequest(handle, priority, workerclass, param);
+	WorkRequest* req = new WorkRequest(handle, workerclass, param);
 
 	bool res = addRequest(req);
 	if (!res)
@@ -160,8 +160,8 @@ void LLWorkerThread::deleteWorker(LLWorkerClass* workerclass)
 //============================================================================
 // Runs on its OWN thread
 
-LLWorkerThread::WorkRequest::WorkRequest(handle_t handle, U32 priority, LLWorkerClass* workerclass, S32 param) :
-	LLQueuedThread::QueuedRequest(handle, priority),
+LLWorkerThread::WorkRequest::WorkRequest(handle_t handle, LLWorkerClass* workerclass, S32 param) :
+	LLQueuedThread::QueuedRequest(handle),
 	mWorkerClass(workerclass),
 	mParam(param)
 {
@@ -180,6 +180,7 @@ void LLWorkerThread::WorkRequest::deleteRequest()
 // virtual
 bool LLWorkerThread::WorkRequest::processRequest()
 {
+    LL_PROFILE_ZONE_SCOPED;
 	LLWorkerClass* workerclass = getWorkerClass();
 	workerclass->setWorking(true);
 	bool complete = workerclass->doWork(getParam());
@@ -190,6 +191,7 @@ bool LLWorkerThread::WorkRequest::processRequest()
 // virtual
 void LLWorkerThread::WorkRequest::finishRequest(bool completed)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	LLWorkerClass* workerclass = getWorkerClass();
 	workerclass->finishWork(getParam(), completed);
 	U32 flags = LLWorkerClass::WCF_WORK_FINISHED | (completed ? 0 : LLWorkerClass::WCF_WORK_ABORTED);
@@ -203,7 +205,6 @@ LLWorkerClass::LLWorkerClass(LLWorkerThread* workerthread, const std::string& na
 	: mWorkerThread(workerthread),
 	  mWorkerClassName(name),
 	  mRequestHandle(LLWorkerThread::nullHandle()),
-	  mRequestPriority(LLWorkerThread::PRIORITY_NORMAL),
 	  mMutex(),
 	  mWorkFlags(0)
 {
@@ -292,7 +293,7 @@ bool LLWorkerClass::yield()
 //----------------------------------------------------------------------------
 
 // calls startWork, adds doWork() to queue
-void LLWorkerClass::addWork(S32 param, U32 priority)
+void LLWorkerClass::addWork(S32 param)
 {
 	mMutex.lock();
 	llassert_always(!(mWorkFlags & (WCF_WORKING|WCF_HAVE_WORK)));
@@ -306,7 +307,7 @@ void LLWorkerClass::addWork(S32 param, U32 priority)
 	startWork(param);
 	clearFlags(WCF_WORK_FINISHED|WCF_WORK_ABORTED);
 	setFlags(WCF_HAVE_WORK);
-	mRequestHandle = mWorkerThread->addWorkRequest(this, param, priority);
+	mRequestHandle = mWorkerThread->addWorkRequest(this, param);
 	mMutex.unlock();
 }
 
@@ -321,7 +322,6 @@ void LLWorkerClass::abortWork(bool autocomplete)
 	if (mRequestHandle != LLWorkerThread::nullHandle())
 	{
 		mWorkerThread->abortRequest(mRequestHandle, autocomplete);
-		mWorkerThread->setPriority(mRequestHandle, LLQueuedThread::PRIORITY_IMMEDIATE);
 		setFlags(WCF_ABORT_REQUESTED);
 	}
 	mMutex.unlock();
@@ -395,16 +395,5 @@ void LLWorkerClass::scheduleDelete()
 	}
 }
 
-void LLWorkerClass::setPriority(U32 priority)
-{
-	mMutex.lock();
-	if (mRequestHandle != LLWorkerThread::nullHandle() && mRequestPriority != priority)
-	{
-		mRequestPriority = priority;
-		mWorkerThread->setPriority(mRequestHandle, priority);
-	}
-	mMutex.unlock();
-}
-
 //============================================================================
 
diff --git a/indra/llcommon/llworkerthread.h b/indra/llcommon/llworkerthread.h
index 0387e75c65..06bbb7369e 100644
--- a/indra/llcommon/llworkerthread.h
+++ b/indra/llcommon/llworkerthread.h
@@ -56,7 +56,7 @@ public:
 		virtual ~WorkRequest(); // use deleteRequest()
 		
 	public:
-		WorkRequest(handle_t handle, U32 priority, LLWorkerClass* workerclass, S32 param);
+		WorkRequest(handle_t handle, LLWorkerClass* workerclass, S32 param);
 
 		S32 getParam()
 		{
@@ -90,7 +90,7 @@ public:
 
 	/*virtual*/ S32 update(F32 max_time_ms);
 	
-	handle_t addWorkRequest(LLWorkerClass* workerclass, S32 param, U32 priority = PRIORITY_NORMAL);
+	handle_t addWorkRequest(LLWorkerClass* workerclass, S32 param);
 	
 	S32 getNumDeletes() { return (S32)mDeleteList.size(); } // debug
 
@@ -151,10 +151,6 @@ public:
 	bool isWorking() { return getFlags(WCF_WORKING); }
 	bool wasAborted() { return getFlags(WCF_ABORT_REQUESTED); }
 
-	// setPriority(): changes the priority of a request
-	void setPriority(U32 priority);
-	U32  getPriority() { return mRequestPriority; }
-		
 	const std::string& getName() const { return mWorkerClassName; }
 
 protected:
@@ -169,7 +165,7 @@ protected:
 	void setWorkerThread(LLWorkerThread* workerthread);
 
 	// addWork(): calls startWork, adds doWork() to queue
-	void addWork(S32 param, U32 priority = LLWorkerThread::PRIORITY_NORMAL);
+	void addWork(S32 param);
 
 	// abortWork(): requests that work be aborted
 	void abortWork(bool autocomplete);
@@ -193,7 +189,6 @@ protected:
 	LLWorkerThread* mWorkerThread;
 	std::string mWorkerClassName;
 	handle_t mRequestHandle;
-	U32 mRequestPriority; // last priority set
 
 private:
 	LLMutex mMutex;
diff --git a/indra/llcommon/threadpool.cpp b/indra/llcommon/threadpool.cpp
index ba914035e2..f49dd40a8b 100644
--- a/indra/llcommon/threadpool.cpp
+++ b/indra/llcommon/threadpool.cpp
@@ -17,14 +17,17 @@
 // std headers
 // external library headers
 // other Linden headers
+#include "commoncontrol.h"
 #include "llerror.h"
 #include "llevents.h"
+#include "llsd.h"
 #include "stringize.h"
 
 LL::ThreadPool::ThreadPool(const std::string& name, size_t threads, size_t capacity):
+    super(name),
     mQueue(name, capacity),
     mName("ThreadPool:" + name),
-    mThreadCount(threads)
+    mThreadCount(getConfiguredWidth(name, threads))
 {}
 
 void LL::ThreadPool::start()
@@ -86,3 +89,58 @@ void LL::ThreadPool::run()
 {
     mQueue.runUntilClose();
 }
+
+//static
+size_t LL::ThreadPool::getConfiguredWidth(const std::string& name, size_t dft)
+{
+    LLSD poolSizes;
+    try
+    {
+        poolSizes = LL::CommonControl::get("Global", "ThreadPoolSizes");
+        // "ThreadPoolSizes" is actually a map containing the sizes of
+        // interest -- or should be, if this process has an
+        // LLViewerControlListener instance and its settings include
+        // "ThreadPoolSizes". If we failed to retrieve it, perhaps we're in a
+        // program that doesn't define that, or perhaps there's no such
+        // setting, or perhaps we're asking too early, before the LLEventAPI
+        // itself has been instantiated. In any of those cases, it seems worth
+        // warning.
+        if (! poolSizes.isDefined())
+        {
+            // Note: we don't warn about absence of an override key for a
+            // particular ThreadPool name, that's fine. This warning is about
+            // complete absence of a ThreadPoolSizes setting, which we expect
+            // in a normal viewer session.
+            LL_WARNS("ThreadPool") << "No 'ThreadPoolSizes' setting for ThreadPool '"
+                                   << name << "'" << LL_ENDL;
+        }
+    }
+    catch (const LL::CommonControl::Error& exc)
+    {
+        // We don't want ThreadPool to *require* LLViewerControlListener.
+        // Just log it and carry on.
+        LL_WARNS("ThreadPool") << "Can't check 'ThreadPoolSizes': " << exc.what() << LL_ENDL;
+    }
+
+    LL_DEBUGS("ThreadPool") << "ThreadPoolSizes = " << poolSizes << LL_ENDL;
+    // LLSD treats an undefined value as an empty map when asked to retrieve a
+    // key, so we don't need this to be conditional.
+    LLSD sizeSpec{ poolSizes[name] };
+    // We retrieve sizeSpec as LLSD, rather than immediately as LLSD::Integer,
+    // so we can distinguish the case when it's undefined.
+    return sizeSpec.isInteger() ? sizeSpec.asInteger() : dft;
+}
+
+//static
+size_t LL::ThreadPool::getWidth(const std::string& name, size_t dft)
+{
+    auto instance{ getInstance(name) };
+    if (instance)
+    {
+        return instance->getWidth();
+    }
+    else
+    {
+        return getConfiguredWidth(name, dft);
+    }
+}
diff --git a/indra/llcommon/threadpool.h b/indra/llcommon/threadpool.h
index b79c9b9090..b49d511257 100644
--- a/indra/llcommon/threadpool.h
+++ b/indra/llcommon/threadpool.h
@@ -22,14 +22,25 @@
 namespace LL
 {
 
-    class ThreadPool
+    class ThreadPool: public LLInstanceTracker<ThreadPool, std::string>
     {
+    private:
+        using super = LLInstanceTracker<ThreadPool, std::string>;
     public:
         /**
          * Pass ThreadPool a string name. This can be used to look up the
          * relevant WorkQueue.
+         *
+         * The number of threads you pass sets the compile-time default. But
+         * if the user has overridden the LLSD map in the "ThreadPoolSizes"
+         * setting with a key matching this ThreadPool name, that setting
+         * overrides this parameter.
+         *
+         * Pass an explicit capacity to limit the size of the queue.
+         * Constraining the queue can cause a submitter to block. Do not
+         * constrain any ThreadPool accepting work from the main thread.
          */
-        ThreadPool(const std::string& name, size_t threads=1, size_t capacity=1024);
+        ThreadPool(const std::string& name, size_t threads=1, size_t capacity=1024*1024);
         virtual ~ThreadPool();
 
         /**
@@ -57,6 +68,25 @@ namespace LL
          */
         virtual void run();
 
+        /**
+         * getConfiguredWidth() returns the setting, if any, for the specified
+         * ThreadPool name. Returns dft if the "ThreadPoolSizes" map does not
+         * contain the specified name.
+         */
+        static
+        size_t getConfiguredWidth(const std::string& name, size_t dft=0);
+
+        /**
+         * This getWidth() returns the width of the instantiated ThreadPool
+         * with the specified name, if any. If no instance exists, returns its
+         * getConfiguredWidth() if any. If there's no instance and no relevant
+         * override, return dft. Presumably dft should match the threads
+         * parameter passed to the ThreadPool constructor call that will
+         * eventually instantiate the ThreadPool with that name.
+         */
+        static
+        size_t getWidth(const std::string& name, size_t dft);
+
     private:
         void run(const std::string& name);
 
diff --git a/indra/llcommon/workqueue.h b/indra/llcommon/workqueue.h
index 96574a18b9..784327f929 100644
--- a/indra/llcommon/workqueue.h
+++ b/indra/llcommon/workqueue.h
@@ -162,9 +162,15 @@ namespace LL
                        CALLABLE&& callable);
 
         template <typename CALLABLE>
+        bool tryPost(const TimePoint& time, CALLABLE&& callable)
+        {
+            return mQueue.tryPush(TimedWork(time, std::move(callable)));
+        }
+
+        template <typename CALLABLE>
         bool tryPost(CALLABLE&& callable)
         {
-            return mQueue.tryPush(TimedWork(TimePoint::clock::now(), std::move(callable)));
+            return mQueue.tryPush(TimePoint::clock::now(), std::move(callable));
         }
 
         /*------------------------- handshake API --------------------------*/
diff --git a/indra/llcorehttp/_httplibcurl.cpp b/indra/llcorehttp/_httplibcurl.cpp
index 975ce8a4d5..bd0ac740db 100644
--- a/indra/llcorehttp/_httplibcurl.cpp
+++ b/indra/llcorehttp/_httplibcurl.cpp
@@ -113,6 +113,7 @@ void HttpLibcurl::shutdown()
 
 void HttpLibcurl::start(int policy_count)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	llassert_always(policy_count <= HTTP_POLICY_CLASS_LIMIT);
 	llassert_always(! mMultiHandles);					// One-time call only
 	
@@ -143,6 +144,7 @@ void HttpLibcurl::start(int policy_count)
 // sleep otherwise ask for a normal polling interval.
 HttpService::ELoopSpeed HttpLibcurl::processTransport()
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	HttpService::ELoopSpeed	ret(HttpService::REQUEST_SLEEP);
 
 	// Give libcurl some cycles to do I/O & callbacks
@@ -168,6 +170,7 @@ HttpService::ELoopSpeed HttpLibcurl::processTransport()
 		CURLMcode status(CURLM_CALL_MULTI_PERFORM);
 		do
 		{
+            LL_PROFILE_ZONE_NAMED_CATEGORY_NETWORK("httppt - curl_multi_perform");
 			running = 0;
 			status = curl_multi_perform(mMultiHandles[policy_class], &running);
 		}
@@ -176,31 +179,34 @@ HttpService::ELoopSpeed HttpLibcurl::processTransport()
 		// Run completion on anything done
 		CURLMsg * msg(NULL);
 		int msgs_in_queue(0);
-		while ((msg = curl_multi_info_read(mMultiHandles[policy_class], &msgs_in_queue)))
-		{
-			if (CURLMSG_DONE == msg->msg)
-			{
-				CURL * handle(msg->easy_handle);
-				CURLcode result(msg->data.result);
+        {
+            LL_PROFILE_ZONE_NAMED_CATEGORY_NETWORK("httppt - curl_multi_info_read");
+            while ((msg = curl_multi_info_read(mMultiHandles[policy_class], &msgs_in_queue)))
+            {
+                if (CURLMSG_DONE == msg->msg)
+                {
+                    CURL* handle(msg->easy_handle);
+                    CURLcode result(msg->data.result);
 
-				completeRequest(mMultiHandles[policy_class], handle, result);
-				handle = NULL;					// No longer valid on return
-				ret = HttpService::NORMAL;		// If anything completes, we may have a free slot.
-												// Turning around quickly reduces connection gap by 7-10mS.
-			}
-			else if (CURLMSG_NONE == msg->msg)
-			{
-				// Ignore this... it shouldn't mean anything.
-				;
-			}
-			else
-			{
-				LL_WARNS_ONCE(LOG_CORE) << "Unexpected message from libcurl.  Msg code:  "
-										<< msg->msg
-										<< LL_ENDL;
-			}
-			msgs_in_queue = 0;
-		}
+                    completeRequest(mMultiHandles[policy_class], handle, result);
+                    handle = NULL;					// No longer valid on return
+                    ret = HttpService::NORMAL;		// If anything completes, we may have a free slot.
+                                                    // Turning around quickly reduces connection gap by 7-10mS.
+                }
+                else if (CURLMSG_NONE == msg->msg)
+                {
+                    // Ignore this... it shouldn't mean anything.
+                    ;
+                }
+                else
+                {
+                    LL_WARNS_ONCE(LOG_CORE) << "Unexpected message from libcurl.  Msg code:  "
+                        << msg->msg
+                        << LL_ENDL;
+                }
+                msgs_in_queue = 0;
+            }
+        }
 	}
 
 	if (! mActiveOps.empty())
@@ -214,6 +220,7 @@ HttpService::ELoopSpeed HttpLibcurl::processTransport()
 // Caller has provided us with a ref count on op.
 void HttpLibcurl::addOp(const HttpOpRequest::ptr_t &op)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	llassert_always(op->mReqPolicy < mPolicyCount);
 	llassert_always(mMultiHandles[op->mReqPolicy] != NULL);
 	
@@ -257,6 +264,7 @@ void HttpLibcurl::addOp(const HttpOpRequest::ptr_t &op)
 // method to kill the request.
 bool HttpLibcurl::cancel(HttpHandle handle)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
     HttpOpRequest::ptr_t op = HttpOpRequest::fromHandle<HttpOpRequest>(handle);
 	active_set_t::iterator it(mActiveOps.find(op));
 	if (mActiveOps.end() == it)
@@ -282,6 +290,7 @@ bool HttpLibcurl::cancel(HttpHandle handle)
 // op to the reply queue with refcount intact.
 void HttpLibcurl::cancelRequest(const HttpOpRequest::ptr_t &op)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	// Deactivate request
 	op->mCurlActive = false;
 
@@ -308,6 +317,7 @@ void HttpLibcurl::cancelRequest(const HttpOpRequest::ptr_t &op)
 // Keep them synchronized as necessary.
 bool HttpLibcurl::completeRequest(CURLM * multi_handle, CURL * handle, CURLcode status)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
     HttpHandle ophandle(NULL);
 
     CURLcode ccode(CURLE_OK);
@@ -445,6 +455,7 @@ int HttpLibcurl::getActiveCountInClass(int policy_class) const
 
 void HttpLibcurl::policyUpdated(int policy_class)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	if (policy_class < 0 || policy_class >= mPolicyCount || ! mMultiHandles)
 	{
 		return;
diff --git a/indra/llcorehttp/_httpoperation.cpp b/indra/llcorehttp/_httpoperation.cpp
index 3fc4e28910..3b64018132 100644
--- a/indra/llcorehttp/_httpoperation.cpp
+++ b/indra/llcorehttp/_httpoperation.cpp
@@ -62,7 +62,6 @@ HttpOperation::HttpOperation():
     mReplyQueue(),
     mUserHandler(),
     mReqPolicy(HttpRequest::DEFAULT_POLICY_ID),
-    mReqPriority(0U),
     mTracing(HTTP_TRACE_OFF),
     mMyHandle(LLCORE_HTTP_HANDLE_INVALID)
 {
diff --git a/indra/llcorehttp/_httpoperation.h b/indra/llcorehttp/_httpoperation.h
index 1a75921c09..8c1364bab4 100644
--- a/indra/llcorehttp/_httpoperation.h
+++ b/indra/llcorehttp/_httpoperation.h
@@ -181,7 +181,6 @@ protected:
 public:
 	// Request Data
 	HttpRequest::policy_t		mReqPolicy;
-	HttpRequest::priority_t		mReqPriority;
 
 	// Reply Data
 	HttpStatus					mStatus;
diff --git a/indra/llcorehttp/_httpoprequest.cpp b/indra/llcorehttp/_httpoprequest.cpp
index ba31290c24..d60eb6c95f 100644
--- a/indra/llcorehttp/_httpoprequest.cpp
+++ b/indra/llcorehttp/_httpoprequest.cpp
@@ -200,6 +200,7 @@ HttpOpRequest::~HttpOpRequest()
 
 void HttpOpRequest::stageFromRequest(HttpService * service)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
     HttpOpRequest::ptr_t self(boost::dynamic_pointer_cast<HttpOpRequest>(shared_from_this()));
     service->getPolicy().addOp(self);			// transfers refcount
 }
@@ -207,6 +208,7 @@ void HttpOpRequest::stageFromRequest(HttpService * service)
 
 void HttpOpRequest::stageFromReady(HttpService * service)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
     HttpOpRequest::ptr_t self(boost::dynamic_pointer_cast<HttpOpRequest>(shared_from_this()));
     service->getTransport().addOp(self);		// transfers refcount
 }
@@ -214,6 +216,7 @@ void HttpOpRequest::stageFromReady(HttpService * service)
 
 void HttpOpRequest::stageFromActive(HttpService * service)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	if (mReplyLength)
 	{
 		// If non-zero, we received and processed a Content-Range
@@ -250,6 +253,7 @@ void HttpOpRequest::stageFromActive(HttpService * service)
 
 void HttpOpRequest::visitNotifier(HttpRequest * request)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	if (mUserHandler)
 	{
 		HttpResponse * response = new HttpResponse();
@@ -292,6 +296,7 @@ void HttpOpRequest::visitNotifier(HttpRequest * request)
 
 HttpStatus HttpOpRequest::cancel()
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	mStatus = HttpStatus(HttpStatus::LLCORE, HE_OP_CANCELED);
 
 	addAsReply();
@@ -301,12 +306,12 @@ HttpStatus HttpOpRequest::cancel()
 
 
 HttpStatus HttpOpRequest::setupGet(HttpRequest::policy_t policy_id,
-								   HttpRequest::priority_t priority,
 								   const std::string & url,
                                    const HttpOptions::ptr_t & options,
 								   const HttpHeaders::ptr_t & headers)
 {
-	setupCommon(policy_id, priority, url, NULL, options, headers);
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
+	setupCommon(policy_id, url, NULL, options, headers);
 	mReqMethod = HOR_GET;
 	
 	return HttpStatus();
@@ -314,14 +319,14 @@ HttpStatus HttpOpRequest::setupGet(HttpRequest::policy_t policy_id,
 
 
 HttpStatus HttpOpRequest::setupGetByteRange(HttpRequest::policy_t policy_id,
-											HttpRequest::priority_t priority,
 											const std::string & url,
 											size_t offset,
 											size_t len,
                                             const HttpOptions::ptr_t & options,
                                             const HttpHeaders::ptr_t & headers)
 {
-	setupCommon(policy_id, priority, url, NULL, options, headers);
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
+	setupCommon(policy_id, url, NULL, options, headers);
 	mReqMethod = HOR_GET;
 	mReqOffset = offset;
 	mReqLength = len;
@@ -335,13 +340,13 @@ HttpStatus HttpOpRequest::setupGetByteRange(HttpRequest::policy_t policy_id,
 
 
 HttpStatus HttpOpRequest::setupPost(HttpRequest::policy_t policy_id,
-									HttpRequest::priority_t priority,
 									const std::string & url,
 									BufferArray * body,
                                     const HttpOptions::ptr_t & options,
                                     const HttpHeaders::ptr_t & headers)
 {
-	setupCommon(policy_id, priority, url, body, options, headers);
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
+	setupCommon(policy_id, url, body, options, headers);
 	mReqMethod = HOR_POST;
 	
 	return HttpStatus();
@@ -349,13 +354,13 @@ HttpStatus HttpOpRequest::setupPost(HttpRequest::policy_t policy_id,
 
 
 HttpStatus HttpOpRequest::setupPut(HttpRequest::policy_t policy_id,
-								   HttpRequest::priority_t priority,
 								   const std::string & url,
 								   BufferArray * body,
                                    const HttpOptions::ptr_t & options,
 								   const HttpHeaders::ptr_t & headers)
 {
-	setupCommon(policy_id, priority, url, body, options, headers);
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
+	setupCommon(policy_id, url, body, options, headers);
 	mReqMethod = HOR_PUT;
 	
 	return HttpStatus();
@@ -363,12 +368,12 @@ HttpStatus HttpOpRequest::setupPut(HttpRequest::policy_t policy_id,
 
 
 HttpStatus HttpOpRequest::setupDelete(HttpRequest::policy_t policy_id,
-    HttpRequest::priority_t priority,
     const std::string & url,
     const HttpOptions::ptr_t & options,
     const HttpHeaders::ptr_t & headers)
 {
-    setupCommon(policy_id, priority, url, NULL, options, headers);
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
+    setupCommon(policy_id, url, NULL, options, headers);
     mReqMethod = HOR_DELETE;
 
     return HttpStatus();
@@ -376,13 +381,13 @@ HttpStatus HttpOpRequest::setupDelete(HttpRequest::policy_t policy_id,
 
 
 HttpStatus HttpOpRequest::setupPatch(HttpRequest::policy_t policy_id,
-    HttpRequest::priority_t priority,
     const std::string & url,
     BufferArray * body,
     const HttpOptions::ptr_t & options,
     const HttpHeaders::ptr_t & headers)
 {
-    setupCommon(policy_id, priority, url, body, options, headers);
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
+    setupCommon(policy_id, url, body, options, headers);
     mReqMethod = HOR_PATCH;
 
     return HttpStatus();
@@ -390,12 +395,12 @@ HttpStatus HttpOpRequest::setupPatch(HttpRequest::policy_t policy_id,
 
 
 HttpStatus HttpOpRequest::setupCopy(HttpRequest::policy_t policy_id,
-    HttpRequest::priority_t priority,
     const std::string & url,
     const HttpOptions::ptr_t & options,
     const HttpHeaders::ptr_t &headers)
 {
-    setupCommon(policy_id, priority, url, NULL, options, headers);
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
+    setupCommon(policy_id, url, NULL, options, headers);
     mReqMethod = HOR_COPY;
 
     return HttpStatus();
@@ -403,12 +408,12 @@ HttpStatus HttpOpRequest::setupCopy(HttpRequest::policy_t policy_id,
 
 
 HttpStatus HttpOpRequest::setupMove(HttpRequest::policy_t policy_id,
-    HttpRequest::priority_t priority,
     const std::string & url,
     const HttpOptions::ptr_t & options,
     const HttpHeaders::ptr_t &headers)
 {
-    setupCommon(policy_id, priority, url, NULL, options, headers);
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
+    setupCommon(policy_id, url, NULL, options, headers);
     mReqMethod = HOR_MOVE;
 
     return HttpStatus();
@@ -416,15 +421,14 @@ HttpStatus HttpOpRequest::setupMove(HttpRequest::policy_t policy_id,
 
 
 void HttpOpRequest::setupCommon(HttpRequest::policy_t policy_id,
-								HttpRequest::priority_t priority,
 								const std::string & url,
 								BufferArray * body,
                                 const HttpOptions::ptr_t & options,
 								const HttpHeaders::ptr_t & headers)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	mProcFlags = 0U;
 	mReqPolicy = policy_id;
-	mReqPriority = priority;
 	mReqURL = url;
 	if (body)
 	{
@@ -465,6 +469,7 @@ void HttpOpRequest::setupCommon(HttpRequest::policy_t policy_id,
 // *TODO:  Move this to _httplibcurl where it belongs.
 HttpStatus HttpOpRequest::prepareRequest(HttpService * service)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	// Scrub transport and result data for retried op case
 	mCurlActive = false;
 	mCurlHandle = NULL;
@@ -773,6 +778,7 @@ HttpStatus HttpOpRequest::prepareRequest(HttpService * service)
 
 size_t HttpOpRequest::writeCallback(void * data, size_t size, size_t nmemb, void * userdata)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
     HttpOpRequest::ptr_t op(HttpOpRequest::fromHandle<HttpOpRequest>(userdata));
 
 	if (! op->mReplyBody)
@@ -788,6 +794,7 @@ size_t HttpOpRequest::writeCallback(void * data, size_t size, size_t nmemb, void
 		
 size_t HttpOpRequest::readCallback(void * data, size_t size, size_t nmemb, void * userdata)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
     HttpOpRequest::ptr_t op(HttpOpRequest::fromHandle<HttpOpRequest>(userdata));
 
 	if (! op->mReqBody)
@@ -819,6 +826,7 @@ size_t HttpOpRequest::readCallback(void * data, size_t size, size_t nmemb, void
 
 int HttpOpRequest::seekCallback(void *userdata, curl_off_t offset, int origin)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
     HttpOpRequest::ptr_t op(HttpOpRequest::fromHandle<HttpOpRequest>(userdata));
 
     if (!op->mReqBody)
@@ -850,6 +858,7 @@ int HttpOpRequest::seekCallback(void *userdata, curl_off_t offset, int origin)
 		
 size_t HttpOpRequest::headerCallback(void * data, size_t size, size_t nmemb, void * userdata)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	static const char status_line[] = "HTTP/";
 	static const size_t status_line_len = sizeof(status_line) - 1;
 	static const char con_ran_line[] = "content-range";
@@ -999,6 +1008,7 @@ size_t HttpOpRequest::headerCallback(void * data, size_t size, size_t nmemb, voi
 
 CURLcode HttpOpRequest::curlSslCtxCallback(CURL *curl, void *sslctx, void *userdata)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
     HttpOpRequest::ptr_t op(HttpOpRequest::fromHandle<HttpOpRequest>(userdata));
 
     if (op->mCallbackSSLVerify)
@@ -1025,6 +1035,7 @@ CURLcode HttpOpRequest::curlSslCtxCallback(CURL *curl, void *sslctx, void *userd
 
 int HttpOpRequest::sslCertVerifyCallback(X509_STORE_CTX *ctx, void *param)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
     HttpOpRequest::ptr_t op(HttpOpRequest::fromHandle<HttpOpRequest>(param));
 
 	if (op->mCallbackSSLVerify)
@@ -1037,6 +1048,7 @@ int HttpOpRequest::sslCertVerifyCallback(X509_STORE_CTX *ctx, void *param)
 
 int HttpOpRequest::debugCallback(CURL * handle, curl_infotype info, char * buffer, size_t len, void * userdata)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
     HttpOpRequest::ptr_t op(HttpOpRequest::fromHandle<HttpOpRequest>(userdata));
 
 	std::string safe_line;
diff --git a/indra/llcorehttp/_httpoprequest.h b/indra/llcorehttp/_httpoprequest.h
index cdbe350785..ec84822cf4 100644
--- a/indra/llcorehttp/_httpoprequest.h
+++ b/indra/llcorehttp/_httpoprequest.h
@@ -105,13 +105,11 @@ public:
 	/// Threading:  called by application thread
 	///
 	HttpStatus setupGet(HttpRequest::policy_t policy_id,
-						HttpRequest::priority_t priority,
 						const std::string & url,
 						const HttpOptions::ptr_t & options,
 						const HttpHeaders::ptr_t & headers);
 	
 	HttpStatus setupGetByteRange(HttpRequest::policy_t policy_id,
-								 HttpRequest::priority_t priority,
 								 const std::string & url,
 								 size_t offset,
 								 size_t len,
@@ -119,40 +117,34 @@ public:
 								 const HttpHeaders::ptr_t & headers);
 	
 	HttpStatus setupPost(HttpRequest::policy_t policy_id,
-						 HttpRequest::priority_t priority,
 						 const std::string & url,
 						 BufferArray * body,
                          const HttpOptions::ptr_t & options,
 						 const HttpHeaders::ptr_t & headers);
 	
 	HttpStatus setupPut(HttpRequest::policy_t policy_id,
-						HttpRequest::priority_t priority,
 						const std::string & url,
 						BufferArray * body,
                         const HttpOptions::ptr_t & options,
 						const HttpHeaders::ptr_t & headers);
 
     HttpStatus setupDelete(HttpRequest::policy_t policy_id,
-                        HttpRequest::priority_t priority,
                         const std::string & url,
                         const HttpOptions::ptr_t & options,
                         const HttpHeaders::ptr_t & headers);
 
     HttpStatus setupPatch(HttpRequest::policy_t policy_id,
-                        HttpRequest::priority_t priority,
                         const std::string & url,
                         BufferArray * body,
                         const HttpOptions::ptr_t & options,
                         const HttpHeaders::ptr_t & headers);
 
     HttpStatus setupCopy(HttpRequest::policy_t policy_id,
-                        HttpRequest::priority_t priority,
                         const std::string & url,
                         const HttpOptions::ptr_t & options,
                         const HttpHeaders::ptr_t & headers);
 
     HttpStatus setupMove(HttpRequest::policy_t policy_id,
-                        HttpRequest::priority_t priority,
                         const std::string & url,
                         const HttpOptions::ptr_t & options,
                         const HttpHeaders::ptr_t & headers);
@@ -172,7 +164,6 @@ protected:
 	// Threading:  called by application thread
 	//
 	void setupCommon(HttpRequest::policy_t policy_id,
-					 HttpRequest::priority_t priority,
 					 const std::string & url,
 					 BufferArray * body,
                      const HttpOptions::ptr_t & options,
@@ -239,19 +230,6 @@ public:
 
 
 
-/// HttpOpRequestCompare isn't an operation but a uniform comparison
-/// functor for STL containers that order by priority.  Mainly
-/// used for the ready queue container but defined here.
-class HttpOpRequestCompare
-{
-public:
-	bool operator()(const HttpOpRequest * lhs, const HttpOpRequest * rhs)
-		{
-			return lhs->mReqPriority > rhs->mReqPriority;
-		}
-};  // end class HttpOpRequestCompare
-
-
 // ---------------------------------------
 // Free functions
 // ---------------------------------------
diff --git a/indra/llcorehttp/_httpopsetpriority.cpp b/indra/llcorehttp/_httpopsetpriority.cpp
index d48c7a0b7d..b99b4e9e4a 100644
--- a/indra/llcorehttp/_httpopsetpriority.cpp
+++ b/indra/llcorehttp/_httpopsetpriority.cpp
@@ -24,6 +24,7 @@
  * $/LicenseInfo$
  */
 
+#if 0 // DEPRECATED
 #include "_httpopsetpriority.h"
 
 #include "httpresponse.h"
@@ -61,3 +62,5 @@ void HttpOpSetPriority::stageFromRequest(HttpService * service)
 
 
 }   // end namespace LLCore
+
+#endif
diff --git a/indra/llcorehttp/_httpopsetpriority.h b/indra/llcorehttp/_httpopsetpriority.h
index 43e2aa081b..fd543f37cc 100644
--- a/indra/llcorehttp/_httpopsetpriority.h
+++ b/indra/llcorehttp/_httpopsetpriority.h
@@ -27,7 +27,7 @@
 #ifndef	_LLCORE_HTTP_SETPRIORITY_H_
 #define	_LLCORE_HTTP_SETPRIORITY_H_
 
-
+#if 0 // DEPRECATED
 #include "httpcommon.h"
 #include "httprequest.h"
 #include "_httpoperation.h"
@@ -49,7 +49,7 @@ namespace LLCore
 class HttpOpSetPriority : public HttpOperation
 {
 public:
-	HttpOpSetPriority(HttpHandle handle, HttpRequest::priority_t priority);
+	HttpOpSetPriority(HttpHandle handle);
 
 	virtual ~HttpOpSetPriority();
 
@@ -63,10 +63,10 @@ public:
 protected:
 	// Request Data
 	HttpHandle					mHandle;
-	HttpRequest::priority_t		mPriority;
 }; // end class HttpOpSetPriority
 
 }  // end namespace LLCore
+#endif
 
 #endif	// _LLCORE_HTTP_SETPRIORITY_H_
 
diff --git a/indra/llcorehttp/_httppolicy.cpp b/indra/llcorehttp/_httppolicy.cpp
index 885f0ed61d..29f50c1693 100644
--- a/indra/llcorehttp/_httppolicy.cpp
+++ b/indra/llcorehttp/_httppolicy.cpp
@@ -330,37 +330,6 @@ HttpService::ELoopSpeed HttpPolicy::processReadyQueue()
 	return result;
 }
 
-
-bool HttpPolicy::changePriority(HttpHandle handle, HttpRequest::priority_t priority)
-{
-	for (int policy_class(0); policy_class < mClasses.size(); ++policy_class)
-	{
-		ClassState & state(*mClasses[policy_class]);
-		// We don't scan retry queue because a priority change there
-		// is meaningless.  The request will be issued based on retry
-		// intervals not priority value, which is now moot.
-		
-		// Scan ready queue for requests that match policy
-		HttpReadyQueue::container_type & c(state.mReadyQueue.get_container());
-		for (HttpReadyQueue::container_type::iterator iter(c.begin()); c.end() != iter;)
-		{
-			HttpReadyQueue::container_type::iterator cur(iter++);
-
-			if ((*cur)->getHandle() == handle)
-			{
-				HttpOpRequest::ptr_t op(*cur);
-				c.erase(cur);									// All iterators are now invalidated
-				op->mReqPriority = priority;
-				state.mReadyQueue.push(op);						// Re-insert using adapter class
-				return true;
-			}
-		}
-	}
-	
-	return false;
-}
-
-
 bool HttpPolicy::cancel(HttpHandle handle)
 {
 	for (int policy_class(0); policy_class < mClasses.size(); ++policy_class)
diff --git a/indra/llcorehttp/_httppolicy.h b/indra/llcorehttp/_httppolicy.h
index 3c4126e14b..0b8806a3e2 100644
--- a/indra/llcorehttp/_httppolicy.h
+++ b/indra/llcorehttp/_httppolicy.h
@@ -110,12 +110,6 @@ public:
 	/// Threading:  called by worker thread
     void retryOp(const opReqPtr_t &);
 
-	/// Attempt to change the priority of an earlier request.
-	/// Request that Shadows HttpService's method
-	///
-	/// Threading:  called by worker thread
-	bool changePriority(HttpHandle handle, HttpRequest::priority_t priority);
-
 	/// Attempt to cancel a previous request.
 	/// Shadows HttpService's method as well
 	///
diff --git a/indra/llcorehttp/_httpservice.cpp b/indra/llcorehttp/_httpservice.cpp
index 56f52f1b09..294acd7f63 100644
--- a/indra/llcorehttp/_httpservice.cpp
+++ b/indra/llcorehttp/_httpservice.cpp
@@ -80,6 +80,7 @@ HttpService::HttpService()
 
 HttpService::~HttpService()
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	mExitRequested = 1U;
 	if (RUNNING == sState)
 	{
@@ -131,6 +132,7 @@ HttpService::~HttpService()
 
 void HttpService::init(HttpRequestQueue * queue)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	llassert_always(! sInstance);
 	llassert_always(NOT_INITIALIZED == sState);
 	sInstance = new HttpService();
@@ -145,6 +147,7 @@ void HttpService::init(HttpRequestQueue * queue)
 
 void HttpService::term()
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	if (sInstance)
 	{
 		if (RUNNING == sState && sInstance->mThread)
@@ -196,6 +199,7 @@ bool HttpService::isStopped()
 /// Threading:  callable by consumer thread *once*.
 void HttpService::startThread()
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	llassert_always(! mThread || STOPPED == sState);
 	llassert_always(INITIALIZED == sState || STOPPED == sState);
 
@@ -220,22 +224,6 @@ void HttpService::stopRequested()
 }
 
 
-/// Threading:  callable by worker thread.
-bool HttpService::changePriority(HttpHandle handle, HttpRequest::priority_t priority)
-{
-	bool found(false);
-
-	// Skip the request queue as we currently don't leave earlier
-	// requests sitting there.  Start with the ready queue...
-	found = mPolicy->changePriority(handle, priority);
-
-	// If not there, we could try the transport/active queue but priority
-	// doesn't really have much effect there so we don't waste cycles.
-	
-	return found;
-}
-
-
 /// Try to find the given request handle on any of the request
 /// queues and cancel the operation.
 ///
@@ -244,6 +232,7 @@ bool HttpService::changePriority(HttpHandle handle, HttpRequest::priority_t prio
 /// Threading:  callable by worker thread.
 bool HttpService::cancel(HttpHandle handle)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	bool canceled(false);
 
 	// Request can't be on request queue so skip that.
@@ -264,6 +253,7 @@ bool HttpService::cancel(HttpHandle handle)
 /// Threading:  callable by worker thread.
 void HttpService::shutdown()
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	// Disallow future enqueue of requests
 	mRequestQueue->stopQueue();
 
@@ -293,6 +283,8 @@ void HttpService::shutdown()
 // requested to stop.
 void HttpService::threadRun(LLCoreInt::HttpThread * thread)
 {
+    LL_PROFILER_SET_THREAD_NAME("HttpService");
+
 	boost::this_thread::disable_interruption di;
 
 	LLThread::registerThreadID();
@@ -300,6 +292,7 @@ void HttpService::threadRun(LLCoreInt::HttpThread * thread)
 	ELoopSpeed loop(REQUEST_SLEEP);
 	while (! mExitRequested)
 	{
+        LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
         try
         {
 		    loop = processRequestQueue(loop);
@@ -344,6 +337,7 @@ void HttpService::threadRun(LLCoreInt::HttpThread * thread)
 
 HttpService::ELoopSpeed HttpService::processRequestQueue(ELoopSpeed loop)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	HttpRequestQueue::OpContainer ops;
 	const bool wait_for_req(REQUEST_SLEEP == loop);
 	
@@ -384,6 +378,7 @@ HttpService::ELoopSpeed HttpService::processRequestQueue(ELoopSpeed loop)
 HttpStatus HttpService::getPolicyOption(HttpRequest::EPolicyOption opt, HttpRequest::policy_t pclass,
 										long * ret_value)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	if (opt < HttpRequest::PO_CONNECTION_LIMIT											// option must be in range
 		|| opt >= HttpRequest::PO_LAST													// ditto
 		|| (! sOptionDesc[opt].mIsLong)													// datatype is long
@@ -416,6 +411,7 @@ HttpStatus HttpService::getPolicyOption(HttpRequest::EPolicyOption opt, HttpRequ
 HttpStatus HttpService::getPolicyOption(HttpRequest::EPolicyOption opt, HttpRequest::policy_t pclass,
 										std::string * ret_value)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	HttpStatus status(HttpStatus::LLCORE, LLCore::HE_INVALID_ARG);
 
 	if (opt < HttpRequest::PO_CONNECTION_LIMIT											// option must be in range
@@ -443,6 +439,7 @@ HttpStatus HttpService::getPolicyOption(HttpRequest::EPolicyOption opt, HttpRequ
 HttpStatus HttpService::getPolicyOption(HttpRequest::EPolicyOption opt, HttpRequest::policy_t pclass,
 	HttpRequest::policyCallback_t * ret_value)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	HttpStatus status(HttpStatus::LLCORE, LLCore::HE_INVALID_ARG);
 
 	if (opt < HttpRequest::PO_CONNECTION_LIMIT											// option must be in range
@@ -472,6 +469,7 @@ HttpStatus HttpService::getPolicyOption(HttpRequest::EPolicyOption opt, HttpRequ
 HttpStatus HttpService::setPolicyOption(HttpRequest::EPolicyOption opt, HttpRequest::policy_t pclass,
 										long value, long * ret_value)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	HttpStatus status(HttpStatus::LLCORE, LLCore::HE_INVALID_ARG);
 	
 	if (opt < HttpRequest::PO_CONNECTION_LIMIT											// option must be in range
@@ -517,6 +515,7 @@ HttpStatus HttpService::setPolicyOption(HttpRequest::EPolicyOption opt, HttpRequ
 HttpStatus HttpService::setPolicyOption(HttpRequest::EPolicyOption opt, HttpRequest::policy_t pclass,
 										const std::string & value, std::string * ret_value)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	HttpStatus status(HttpStatus::LLCORE, LLCore::HE_INVALID_ARG);
 	
 	if (opt < HttpRequest::PO_CONNECTION_LIMIT											// option must be in range
@@ -548,6 +547,7 @@ HttpStatus HttpService::setPolicyOption(HttpRequest::EPolicyOption opt, HttpRequ
 HttpStatus HttpService::setPolicyOption(HttpRequest::EPolicyOption opt, HttpRequest::policy_t pclass,
 	HttpRequest::policyCallback_t value, HttpRequest::policyCallback_t * ret_value)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	HttpStatus status(HttpStatus::LLCORE, LLCore::HE_INVALID_ARG);
 
 	if (opt < HttpRequest::PO_CONNECTION_LIMIT											// option must be in range
diff --git a/indra/llcorehttp/_httpservice.h b/indra/llcorehttp/_httpservice.h
index d0c37ac195..551a718f20 100644
--- a/indra/llcorehttp/_httpservice.h
+++ b/indra/llcorehttp/_httpservice.h
@@ -147,15 +147,6 @@ public:
 	void shutdown();
 
 	/// Try to find the given request handle on any of the request
-	/// queues and reset the priority (and queue position) of the
-	/// request if found.
-	///
-	/// @return			True if the request was found somewhere.
-	///
-	/// Threading:  callable by worker thread.
-	bool changePriority(HttpHandle handle, HttpRequest::priority_t priority);
-	
-	/// Try to find the given request handle on any of the request
 	/// queues and cancel the operation.
 	///
 	/// @return			True if the request was found and canceled.
diff --git a/indra/llcorehttp/examples/http_texture_load.cpp b/indra/llcorehttp/examples/http_texture_load.cpp
index c7376042b3..cc53b20add 100644
--- a/indra/llcorehttp/examples/http_texture_load.cpp
+++ b/indra/llcorehttp/examples/http_texture_load.cpp
@@ -469,11 +469,11 @@ bool WorkingSet::reload(LLCore::HttpRequest * hr, LLCore::HttpOptions::ptr_t & o
 		LLCore::HttpHandle handle;
 		if (offset || length)
 		{
-			handle = hr->requestGetByteRange(0, 0, buffer, offset, length, opt, mHeaders, LLCore::HttpHandler::ptr_t(this, NoOpDeletor));
+			handle = hr->requestGetByteRange(0, buffer, offset, length, opt, mHeaders, LLCore::HttpHandler::ptr_t(this, NoOpDeletor));
 		}
 		else
 		{
-            handle = hr->requestGet(0, 0, buffer, opt, mHeaders, LLCore::HttpHandler::ptr_t(this, NoOpDeletor));
+            handle = hr->requestGet(0, buffer, opt, mHeaders, LLCore::HttpHandler::ptr_t(this, NoOpDeletor));
 		}
 		if (! handle)
 		{
diff --git a/indra/llcorehttp/httprequest.cpp b/indra/llcorehttp/httprequest.cpp
index 2687f77217..de3854a101 100644
--- a/indra/llcorehttp/httprequest.cpp
+++ b/indra/llcorehttp/httprequest.cpp
@@ -32,7 +32,6 @@
 #include "_httppolicy.h"
 #include "_httpoperation.h"
 #include "_httpoprequest.h"
-#include "_httpopsetpriority.h"
 #include "_httpopcancel.h"
 #include "_httpopsetget.h"
 
@@ -183,16 +182,16 @@ HttpStatus HttpRequest::getStatus() const
 
 
 HttpHandle HttpRequest::requestGet(policy_t policy_id,
-								   priority_t priority,
 								   const std::string & url,
                                    const HttpOptions::ptr_t & options,
 								   const HttpHeaders::ptr_t & headers,
 								   HttpHandler::ptr_t user_handler)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	HttpStatus status;
 
 	HttpOpRequest::ptr_t op(new HttpOpRequest());
-	if (! (status = op->setupGet(policy_id, priority, url, options, headers)))
+	if (! (status = op->setupGet(policy_id, url, options, headers)))
 	{
 		mLastReqStatus = status;
         return LLCORE_HTTP_HANDLE_INVALID;
@@ -210,7 +209,6 @@ HttpHandle HttpRequest::requestGet(policy_t policy_id,
 
 
 HttpHandle HttpRequest::requestGetByteRange(policy_t policy_id,
-											priority_t priority,
 											const std::string & url,
 											size_t offset,
 											size_t len,
@@ -218,10 +216,11 @@ HttpHandle HttpRequest::requestGetByteRange(policy_t policy_id,
 											const HttpHeaders::ptr_t & headers,
 											HttpHandler::ptr_t user_handler)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
 	HttpStatus status;
 
 	HttpOpRequest::ptr_t op(new HttpOpRequest());
-	if (! (status = op->setupGetByteRange(policy_id, priority, url, offset, len, options, headers)))
+	if (! (status = op->setupGetByteRange(policy_id, url, offset, len, options, headers)))
 	{
 		mLastReqStatus = status;
         return LLCORE_HTTP_HANDLE_INVALID;
@@ -239,7 +238,6 @@ HttpHandle HttpRequest::requestGetByteRange(policy_t policy_id,
 
 
 HttpHandle HttpRequest::requestPost(policy_t policy_id,
-									priority_t priority,
 									const std::string & url,
 									BufferArray * body,
                                     const HttpOptions::ptr_t & options,
@@ -249,7 +247,7 @@ HttpHandle HttpRequest::requestPost(policy_t policy_id,
 	HttpStatus status;
 
 	HttpOpRequest::ptr_t op(new HttpOpRequest());
-	if (! (status = op->setupPost(policy_id, priority, url, body, options, headers)))
+	if (! (status = op->setupPost(policy_id, url, body, options, headers)))
 	{
 		mLastReqStatus = status;
         return LLCORE_HTTP_HANDLE_INVALID;
@@ -267,7 +265,6 @@ HttpHandle HttpRequest::requestPost(policy_t policy_id,
 
 
 HttpHandle HttpRequest::requestPut(policy_t policy_id,
-								   priority_t priority,
 								   const std::string & url,
 								   BufferArray * body,
                                    const HttpOptions::ptr_t & options,
@@ -277,7 +274,7 @@ HttpHandle HttpRequest::requestPut(policy_t policy_id,
 	HttpStatus status;
 
 	HttpOpRequest::ptr_t op (new HttpOpRequest());
-	if (! (status = op->setupPut(policy_id, priority, url, body, options, headers)))
+	if (! (status = op->setupPut(policy_id, url, body, options, headers)))
 	{
 		mLastReqStatus = status;
         return LLCORE_HTTP_HANDLE_INVALID;
@@ -294,7 +291,6 @@ HttpHandle HttpRequest::requestPut(policy_t policy_id,
 }
 
 HttpHandle HttpRequest::requestDelete(policy_t policy_id,
-    priority_t priority,
     const std::string & url,
     const HttpOptions::ptr_t & options,
     const HttpHeaders::ptr_t & headers,
@@ -303,7 +299,7 @@ HttpHandle HttpRequest::requestDelete(policy_t policy_id,
     HttpStatus status;
 
     HttpOpRequest::ptr_t op(new HttpOpRequest());
-    if (!(status = op->setupDelete(policy_id, priority, url, options, headers)))
+    if (!(status = op->setupDelete(policy_id, url, options, headers)))
     {
         mLastReqStatus = status;
         return LLCORE_HTTP_HANDLE_INVALID;
@@ -320,7 +316,6 @@ HttpHandle HttpRequest::requestDelete(policy_t policy_id,
 }
 
 HttpHandle HttpRequest::requestPatch(policy_t policy_id,
-    priority_t priority,
     const std::string & url,
     BufferArray * body,
     const HttpOptions::ptr_t & options,
@@ -330,7 +325,7 @@ HttpHandle HttpRequest::requestPatch(policy_t policy_id,
     HttpStatus status;
 
     HttpOpRequest::ptr_t op (new HttpOpRequest());
-    if (!(status = op->setupPatch(policy_id, priority, url, body, options, headers)))
+    if (!(status = op->setupPatch(policy_id, url, body, options, headers)))
     {
         mLastReqStatus = status;
         return LLCORE_HTTP_HANDLE_INVALID;
@@ -347,7 +342,6 @@ HttpHandle HttpRequest::requestPatch(policy_t policy_id,
 }
 
 HttpHandle HttpRequest::requestCopy(policy_t policy_id,
-    priority_t priority,
     const std::string & url,
     const HttpOptions::ptr_t & options,
     const HttpHeaders::ptr_t & headers,
@@ -356,7 +350,7 @@ HttpHandle HttpRequest::requestCopy(policy_t policy_id,
     HttpStatus status;
 
     HttpOpRequest::ptr_t op(new HttpOpRequest());
-    if (!(status = op->setupCopy(policy_id, priority, url, options, headers)))
+    if (!(status = op->setupCopy(policy_id, url, options, headers)))
     {
         mLastReqStatus = status;
         return LLCORE_HTTP_HANDLE_INVALID;
@@ -374,7 +368,6 @@ HttpHandle HttpRequest::requestCopy(policy_t policy_id,
 }
 
 HttpHandle HttpRequest::requestMove(policy_t policy_id,
-    priority_t priority,
     const std::string & url,
     const HttpOptions::ptr_t & options,
     const HttpHeaders::ptr_t & headers,
@@ -383,7 +376,7 @@ HttpHandle HttpRequest::requestMove(policy_t policy_id,
     HttpStatus status;
 
     HttpOpRequest::ptr_t op (new HttpOpRequest());
-    if (!(status = op->setupMove(policy_id, priority, url, options, headers)))
+    if (!(status = op->setupMove(policy_id, url, options, headers)))
     {
         mLastReqStatus = status;
         return LLCORE_HTTP_HANDLE_INVALID;
@@ -483,24 +476,6 @@ HttpHandle HttpRequest::requestCancel(HttpHandle request, HttpHandler::ptr_t use
 }
 
 
-HttpHandle HttpRequest::requestSetPriority(HttpHandle request, priority_t priority,
-										   HttpHandler::ptr_t handler)
-{
-	HttpStatus status;
-
-	HttpOperation::ptr_t op (new HttpOpSetPriority(request, priority));
-	op->setReplyPath(mReplyQueue, handler);
-	if (! (status = mRequestQueue->addOp(op)))			// transfers refcount
-	{
-		mLastReqStatus = status;
-        return LLCORE_HTTP_HANDLE_INVALID;
-	}
-
-	mLastReqStatus = status;
-	return op->getHandle();
-}
-
-
 // ====================================
 // Utility Methods
 // ====================================
diff --git a/indra/llcorehttp/httprequest.h b/indra/llcorehttp/httprequest.h
index a418eb6a7a..ca4b9e92bc 100644
--- a/indra/llcorehttp/httprequest.h
+++ b/indra/llcorehttp/httprequest.h
@@ -95,7 +95,6 @@ private:
 
 public:
 	typedef unsigned int policy_t;
-	typedef unsigned int priority_t;
 	
 	typedef boost::shared_ptr<HttpRequest> ptr_t;
     typedef boost::weak_ptr<HttpRequest>   wptr_t;
@@ -316,8 +315,6 @@ public:
 	///
 	/// @param	policy_id		Default or user-defined policy class under
 	///							which this request is to be serviced.
-	/// @param	priority		Standard priority scheme inherited from
-	///							Indra code base (U32-type scheme).
 	/// @param	url				URL with any encoded query parameters to
 	///							be accessed.
 	/// @param	options			Optional instance of an HttpOptions object
@@ -346,7 +343,6 @@ public:
 	///							case, @see getStatus() will return more info.
 	///
 	HttpHandle requestGet(policy_t policy_id,
-						  priority_t priority,
 						  const std::string & url,
                           const HttpOptions::ptr_t & options,
 						  const HttpHeaders::ptr_t & headers,
@@ -377,7 +373,6 @@ public:
 	/// - Referer:
 	///
 	/// @param	policy_id		@see requestGet()
-	/// @param	priority		"
 	/// @param	url				"
 	/// @param	offset			Offset of first byte into resource to be returned.
 	/// @param	len				Count of bytes to be returned
@@ -387,7 +382,6 @@ public:
 	/// @return					"
 	///
 	HttpHandle requestGetByteRange(policy_t policy_id,
-								   priority_t priority,
 								   const std::string & url,
 								   size_t offset,
 								   size_t len,
@@ -418,7 +412,6 @@ public:
 	/// - Expect:
 	///
 	/// @param	policy_id		@see requestGet()
-	/// @param	priority		"
 	/// @param	url				"
 	/// @param	body			Byte stream to be sent as the body.  No
 	///							further encoding or escaping will be done
@@ -429,7 +422,6 @@ public:
 	/// @return					"
 	///
 	HttpHandle requestPost(policy_t policy_id,
-						   priority_t priority,
 						   const std::string & url,
 						   BufferArray * body,
                            const HttpOptions::ptr_t & options,
@@ -459,7 +451,6 @@ public:
 	/// - Content-Type:
 	///
 	/// @param	policy_id		@see requestGet()
-	/// @param	priority		"
 	/// @param	url				"
 	/// @param	body			Byte stream to be sent as the body.  No
 	///							further encoding or escaping will be done
@@ -470,7 +461,6 @@ public:
 	/// @return					"
 	///
 	HttpHandle requestPut(policy_t policy_id,
-						  priority_t priority,
 						  const std::string & url,
 						  BufferArray * body,
                           const HttpOptions::ptr_t & options,
@@ -483,7 +473,6 @@ public:
     /// encoding and communicating the content types.
     ///
     /// @param	policy_id		@see requestGet()
-    /// @param	priority		"
     /// @param	url				"
     /// @param	options			@see requestGet()K(optional)
     /// @param	headers			"
@@ -491,7 +480,6 @@ public:
     /// @return					"
     ///
     HttpHandle requestDelete(policy_t policy_id,
-            priority_t priority,
             const std::string & url,
             const HttpOptions::ptr_t & options,
             const HttpHeaders::ptr_t & headers,
@@ -502,7 +490,6 @@ public:
     /// encoding and communicating the content types.
     ///
     /// @param	policy_id		@see requestGet()
-    /// @param	priority		"
     /// @param	url				"
     /// @param	body			Byte stream to be sent as the body.  No
     ///							further encoding or escaping will be done
@@ -513,7 +500,6 @@ public:
     /// @return					"
     ///
     HttpHandle requestPatch(policy_t policy_id,
-            priority_t priority,
             const std::string & url,
             BufferArray * body,
             const HttpOptions::ptr_t & options,
@@ -525,7 +511,6 @@ public:
     /// encoding and communicating the content types.
     ///
     /// @param	policy_id		@see requestGet()
-    /// @param	priority		"
     /// @param	url				"
     /// @param	options			@see requestGet()K(optional)
     /// @param	headers			"
@@ -533,7 +518,6 @@ public:
     /// @return					"
     ///
     HttpHandle requestCopy(policy_t policy_id,
-            priority_t priority,
             const std::string & url,
             const HttpOptions::ptr_t & options,
             const HttpHeaders::ptr_t & headers,
@@ -544,7 +528,6 @@ public:
     /// encoding and communicating the content types.
     ///
     /// @param	policy_id		@see requestGet()
-    /// @param	priority		"
     /// @param	url				"
     /// @param	options			@see requestGet()K(optional)
     /// @param	headers			"
@@ -552,7 +535,6 @@ public:
     /// @return					"
     ///
     HttpHandle requestMove(policy_t policy_id,
-            priority_t priority,
             const std::string & url,
             const HttpOptions::ptr_t & options,
             const HttpHeaders::ptr_t & headers,
@@ -593,18 +575,6 @@ public:
 	
 	HttpHandle requestCancel(HttpHandle request, HttpHandler::ptr_t);
 
-	/// Request that a previously-issued request be reprioritized.
-	/// The status of whether the change itself succeeded arrives
-	/// via notification.  
-	///
-	/// @param	request			Handle of previously-issued request to
-	///							be changed.
-	/// @param	priority		New priority value.
-	/// @param	handler			@see requestGet()
-	/// @return					"
-	///
-	HttpHandle requestSetPriority(HttpHandle request, priority_t priority, HttpHandler::ptr_t handler);
-
 	/// @}
 
 	/// @name UtilityMethods
diff --git a/indra/llcorehttp/tests/test_httprequest.hpp b/indra/llcorehttp/tests/test_httprequest.hpp
index 154f6b12e9..3eaac10aeb 100644
--- a/indra/llcorehttp/tests/test_httprequest.hpp
+++ b/indra/llcorehttp/tests/test_httprequest.hpp
@@ -614,7 +614,6 @@ void HttpRequestTestObjectType::test<7>()
 		// Issue a GET that can't connect
 		mStatus = HttpStatus(HttpStatus::EXT_CURL_EASY, CURLE_COULDNT_CONNECT);
 		HttpHandle handle = req->requestGetByteRange(HttpRequest::DEFAULT_POLICY_ID,
-													 0U,
 													 "http://127.0.0.1:2/nothing/here",
 													 0,
 													 0,
@@ -716,7 +715,6 @@ void HttpRequestTestObjectType::test<8>()
 		// Issue a GET that *can* connect
 		mStatus = HttpStatus(200);
 		HttpHandle handle = req->requestGet(HttpRequest::DEFAULT_POLICY_ID,
-											0U,
 											url_base,
 											HttpOptions::ptr_t(),
                                             HttpHeaders::ptr_t(),
@@ -812,7 +810,6 @@ void HttpRequestTestObjectType::test<9>()
 		// Issue a GET that *can* connect
 		mStatus = HttpStatus(200);
 		HttpHandle handle = req->requestGetByteRange(HttpRequest::DEFAULT_POLICY_ID,
-													 0U,
 													 url_base,
 													 0,
 													 0,
@@ -913,7 +910,6 @@ void HttpRequestTestObjectType::test<10>()
 		body->append(body_text, strlen(body_text));
 		mStatus = HttpStatus(200);
 		HttpHandle handle = req->requestPut(HttpRequest::DEFAULT_POLICY_ID,
-											0U,
 											url_base,
 											body,
                                             HttpOptions::ptr_t(),
@@ -1020,7 +1016,6 @@ void HttpRequestTestObjectType::test<11>()
 		body->append(body_text, strlen(body_text));
 		mStatus = HttpStatus(200);
 		HttpHandle handle = req->requestPost(HttpRequest::DEFAULT_POLICY_ID,
-											 0U,
 											 url_base,
 											 body,
                                              HttpOptions::ptr_t(),
@@ -1127,7 +1122,6 @@ void HttpRequestTestObjectType::test<12>()
 		// Issue a GET that *can* connect
 		mStatus = HttpStatus(200);
 		HttpHandle handle = req->requestGetByteRange(HttpRequest::DEFAULT_POLICY_ID,
-													 0U,
 													 url_base,
 													 0,
 													 0,
@@ -1240,7 +1234,6 @@ void HttpRequestTestObjectType::test<13>()
 			regex_container_t::value_type(boost::regex("X-LL-Special", boost::regex::icase),
 										  boost::regex(".*", boost::regex::icase)));
 		HttpHandle handle = req->requestGetByteRange(HttpRequest::DEFAULT_POLICY_ID,
-													 0U,
 													 url_base,
 													 0,	
 												 0,
@@ -1346,7 +1339,6 @@ void HttpRequestTestObjectType::test<14>()
 		// Issue a GET that sleeps
 		mStatus = HttpStatus(HttpStatus::EXT_CURL_EASY, CURLE_OPERATION_TIMEDOUT);
 		HttpHandle handle = req->requestGetByteRange(HttpRequest::DEFAULT_POLICY_ID,
-													 0U,
 													 url_base,
 													 0,
 													 0,
@@ -1454,7 +1446,6 @@ void HttpRequestTestObjectType::test<15>()
 		mStatus = HttpStatus(200);
 		handler.mCheckContentType = "application/llsd+xml";
 		HttpHandle handle = req->requestGet(HttpRequest::DEFAULT_POLICY_ID,
-											0U,
 											url_base,
                                             HttpOptions::ptr_t(),
                                             HttpHeaders::ptr_t(),
@@ -1609,7 +1600,6 @@ void HttpRequestTestObjectType::test<16>()
 				boost::regex("X-Reflect-content-encoding", boost::regex::icase),
 				boost::regex(".*", boost::regex::icase)));
 		HttpHandle handle = req->requestGet(HttpRequest::DEFAULT_POLICY_ID,
-											0U,
 											url_base + "reflect/",
 											options,
 											HttpHeaders::ptr_t(),
@@ -1684,7 +1674,6 @@ void HttpRequestTestObjectType::test<16>()
 				boost::regex("X-Reflect-content-encoding", boost::regex::icase),
 				boost::regex(".*", boost::regex::icase)));
 		handle = req->requestGetByteRange(HttpRequest::DEFAULT_POLICY_ID,
-										  0U,
 										  url_base + "reflect/",
 										  0,
 										  47,
@@ -1863,7 +1852,6 @@ void HttpRequestTestObjectType::test<17>()
 				boost::regex("X-Reflect-transfer_encoding", boost::regex::icase),
 				boost::regex(".*chunked.*", boost::regex::icase)));
 		HttpHandle handle = req->requestPost(HttpRequest::DEFAULT_POLICY_ID,
-											 0U,
 											 url_base + "reflect/",
 											 ba,
 											 options,
@@ -2049,7 +2037,6 @@ void HttpRequestTestObjectType::test<18>()
 				boost::regex(".*", boost::regex::icase)));
 
 		HttpHandle handle = req->requestPut(HttpRequest::DEFAULT_POLICY_ID,
-											0U,
 											url_base + "reflect/",
 											ba,
 											options,
@@ -2249,7 +2236,6 @@ void HttpRequestTestObjectType::test<19>()
 				boost::regex("X-Reflect-content-encoding", boost::regex::icase),
 				boost::regex(".*", boost::regex::icase)));
 		HttpHandle handle = req->requestGet(HttpRequest::DEFAULT_POLICY_ID,
-											0U,
 											url_base + "reflect/",
 											options,
 											headers,
@@ -2457,7 +2443,6 @@ void HttpRequestTestObjectType::test<20>()
 				boost::regex(".*", boost::regex::icase)));
 
 		HttpHandle handle = req->requestPost(HttpRequest::DEFAULT_POLICY_ID,
-											 0U,
 											 url_base + "reflect/",
 											 ba,
 											 options,
@@ -2666,7 +2651,6 @@ void HttpRequestTestObjectType::test<21>()
 				boost::regex("X-Reflect-content-type", boost::regex::icase),
 				boost::regex("text/html", boost::regex::icase)));
 		HttpHandle handle = req->requestPut(HttpRequest::DEFAULT_POLICY_ID,
-											0U,
 											url_base + "reflect/",
 											ba,
 											options,
@@ -2797,7 +2781,6 @@ void HttpRequestTestObjectType::test<22>()
 			char buffer[128];
 			sprintf(buffer, "/bug2295/%d/", i);
 			HttpHandle handle = req->requestGetByteRange(HttpRequest::DEFAULT_POLICY_ID,
-														 0U,
 														 url_base + buffer,
 														 0,
 														 25,
@@ -2829,7 +2812,6 @@ void HttpRequestTestObjectType::test<22>()
 			char buffer[128];
 			sprintf(buffer, "/bug2295/00000012/%d/", i);
 			HttpHandle handle = req->requestGetByteRange(HttpRequest::DEFAULT_POLICY_ID,
-														 0U,
 														 url_base + buffer,
 														 0,
 														 25,
@@ -2861,7 +2843,6 @@ void HttpRequestTestObjectType::test<22>()
 			char buffer[128];
 			sprintf(buffer, "/bug2295/inv_cont_range/%d/", i);
 			HttpHandle handle = req->requestGetByteRange(HttpRequest::DEFAULT_POLICY_ID,
-														 0U,
 														 url_base + buffer,
 														 0,
 														 25,
@@ -2984,7 +2965,6 @@ void HttpRequestTestObjectType::test<23>()
 			std::ostringstream url;
 			url << url_base << i << "/";
 			HttpHandle handle = req->requestGetByteRange(HttpRequest::DEFAULT_POLICY_ID,
-														 0U,
 														 url.str(),
 														 0,
 														 0,
diff --git a/indra/llcrashlogger/llcrashlogger.cpp b/indra/llcrashlogger/llcrashlogger.cpp
index 0d8fb4863b..bb603d3d7f 100644
--- a/indra/llcrashlogger/llcrashlogger.cpp
+++ b/indra/llcrashlogger/llcrashlogger.cpp
@@ -418,7 +418,7 @@ bool LLCrashLogger::runCrashLogPost(std::string host, LLSD data, std::string msg
 		updateApplication(llformat("%s, try %d...", msg.c_str(), i+1));
 
         LL_INFOS("CRASHREPORT") << "POST crash data to " << host << LL_ENDL;
-        LLCore::HttpHandle handle = LLCoreHttpUtil::requestPostWithLLSD(httpRequest.get(), LLCore::HttpRequest::DEFAULT_POLICY_ID, 0,
+        LLCore::HttpHandle handle = LLCoreHttpUtil::requestPostWithLLSD(httpRequest.get(), LLCore::HttpRequest::DEFAULT_POLICY_ID,
             host, data, httpOpts, LLCore::HttpHeaders::ptr_t(), LLCore::HttpHandler::ptr_t(new LLCrashLoggerHandler));
 
         if (handle == LLCORE_HTTP_HANDLE_INVALID)
diff --git a/indra/llfilesystem/lllfsthread.cpp b/indra/llfilesystem/lllfsthread.cpp
index be8e83a56f..dbb69cd605 100644
--- a/indra/llfilesystem/lllfsthread.cpp
+++ b/indra/llfilesystem/lllfsthread.cpp
@@ -45,8 +45,7 @@ void LLLFSThread::initClass(bool local_is_threaded)
 //static
 S32 LLLFSThread::updateClass(U32 ms_elapsed)
 {
-	sLocal->update((F32)ms_elapsed);
-	return sLocal->getPending();
+	return sLocal->update((F32)ms_elapsed);
 }
 
 //static
@@ -58,6 +57,7 @@ void LLLFSThread::cleanupClass()
 	{
 		sLocal->update(0);
 	}
+    sLocal->shutdown();
 	delete sLocal;
 	sLocal = NULL;
 }
@@ -65,8 +65,7 @@ void LLLFSThread::cleanupClass()
 //----------------------------------------------------------------------------
 
 LLLFSThread::LLLFSThread(bool threaded) :
-	LLQueuedThread("LFS", threaded),
-	mPriorityCounter(PRIORITY_LOWBITS)
+	LLQueuedThread("LFS", threaded)
 {
 	if(!mLocalAPRFilePoolp)
 	{
@@ -84,14 +83,12 @@ LLLFSThread::~LLLFSThread()
 
 LLLFSThread::handle_t LLLFSThread::read(const std::string& filename,	/* Flawfinder: ignore */ 
 										U8* buffer, S32 offset, S32 numbytes,
-										Responder* responder, U32 priority)
+										Responder* responder)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	handle_t handle = generateHandle();
 
-	if (priority == 0) priority = PRIORITY_NORMAL | priorityCounter();
-	else if (priority < PRIORITY_LOW) priority |= PRIORITY_LOW; // All reads are at least PRIORITY_LOW
-
-	Request* req = new Request(this, handle, priority,
+	Request* req = new Request(this, handle,
 							   FILE_READ, filename,
 							   buffer, offset, numbytes,
 							   responder);
@@ -107,13 +104,12 @@ LLLFSThread::handle_t LLLFSThread::read(const std::string& filename,	/* Flawfind
 
 LLLFSThread::handle_t LLLFSThread::write(const std::string& filename,
 										 U8* buffer, S32 offset, S32 numbytes,
-										 Responder* responder, U32 priority)
+										 Responder* responder)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	handle_t handle = generateHandle();
 
-	if (priority == 0) priority = PRIORITY_LOW | priorityCounter();
-	
-	Request* req = new Request(this, handle, priority,
+	Request* req = new Request(this, handle,
 							   FILE_WRITE, filename,
 							   buffer, offset, numbytes,
 							   responder);
@@ -130,11 +126,11 @@ LLLFSThread::handle_t LLLFSThread::write(const std::string& filename,
 //============================================================================
 
 LLLFSThread::Request::Request(LLLFSThread* thread,
-							  handle_t handle, U32 priority,
+							  handle_t handle,
 							  operation_t op, const std::string& filename,
 							  U8* buffer, S32 offset, S32 numbytes,
 							  Responder* responder) :
-	QueuedRequest(handle, priority, FLAG_AUTO_COMPLETE),
+	QueuedRequest(handle, FLAG_AUTO_COMPLETE),
 	mThread(thread),
 	mOperation(op),
 	mFileName(filename),
@@ -157,6 +153,7 @@ LLLFSThread::Request::~Request()
 // virtual, called from own thread
 void LLLFSThread::Request::finishRequest(bool completed)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	if (mResponder.notNull())
 	{
 		mResponder->completed(completed ? mBytesRead : 0);
@@ -166,6 +163,7 @@ void LLLFSThread::Request::finishRequest(bool completed)
 
 void LLLFSThread::Request::deleteRequest()
 {
+    LL_PROFILE_ZONE_SCOPED;
 	if (getStatus() == STATUS_QUEUED)
 	{
 		LL_ERRS() << "Attempt to delete a queued LLLFSThread::Request!" << LL_ENDL;
@@ -180,6 +178,7 @@ void LLLFSThread::Request::deleteRequest()
 
 bool LLLFSThread::Request::processRequest()
 {
+    LL_PROFILE_ZONE_SCOPED;
 	bool complete = false;
 	if (mOperation ==  FILE_READ)
 	{
diff --git a/indra/llfilesystem/lllfsthread.h b/indra/llfilesystem/lllfsthread.h
index 58f658f7ba..f2693a1172 100644
--- a/indra/llfilesystem/lllfsthread.h
+++ b/indra/llfilesystem/lllfsthread.h
@@ -68,7 +68,7 @@ public:
 		
 	public:
 		Request(LLLFSThread* thread,
-				handle_t handle, U32 priority, 
+				handle_t handle,
 				operation_t op, const std::string& filename,
 				U8* buffer, S32 offset, S32 numbytes,
 				Responder* responder);
@@ -120,22 +120,15 @@ public:
 	// Return a Request handle
 	handle_t read(const std::string& filename,	/* Flawfinder: ignore */ 
 				  U8* buffer, S32 offset, S32 numbytes,
-				  Responder* responder, U32 pri=0);
+				  Responder* responder);
 	handle_t write(const std::string& filename,
 				   U8* buffer, S32 offset, S32 numbytes,
-				   Responder* responder, U32 pri=0);
-	
-	// Misc
-	U32 priorityCounter() { return mPriorityCounter-- & PRIORITY_LOWBITS; } // Use to order IO operations
+				   Responder* responder);
 	
 	// static initializers
 	static void initClass(bool local_is_threaded = TRUE); // Setup sLocal
 	static S32 updateClass(U32 ms_elapsed);
 	static void cleanupClass();		// Delete sLocal
-
-	
-private:
-	U32 mPriorityCounter;
 	
 public:
 	static LLLFSThread* sLocal;		// Default local file thread
diff --git a/indra/llimage/llimage.cpp b/indra/llimage/llimage.cpp
index ad7124b5aa..186b01d60c 100644
--- a/indra/llimage/llimage.cpp
+++ b/indra/llimage/llimage.cpp
@@ -798,7 +798,6 @@ U8* LLImageBase::allocateDataSize(S32 width, S32 height, S32 ncomponents, S32 si
 // LLImageRaw
 //---------------------------------------------------------------------------
 
-S32 LLImageRaw::sGlobalRawMemory = 0;
 S32 LLImageRaw::sRawImageCount = 0;
 
 LLImageRaw::LLImageRaw()
@@ -856,16 +855,13 @@ LLImageRaw::~LLImageRaw()
 U8* LLImageRaw::allocateData(S32 size)
 {
 	U8* res = LLImageBase::allocateData(size);
-	sGlobalRawMemory += getDataSize();
 	return res;
 }
 
 // virtual
 U8* LLImageRaw::reallocateData(S32 size)
 {
-	sGlobalRawMemory -= getDataSize();
 	U8* res = LLImageBase::reallocateData(size);
-	sGlobalRawMemory += getDataSize();
 	return res;
 }
 
@@ -878,7 +874,6 @@ void LLImageRaw::releaseData()
 // virtual
 void LLImageRaw::deleteData()
 {
-	sGlobalRawMemory -= getDataSize();
 	LLImageBase::deleteData();
 }
 
diff --git a/indra/llimage/llimage.h b/indra/llimage/llimage.h
index 59c192d9f8..9e50fd502b 100644
--- a/indra/llimage/llimage.h
+++ b/indra/llimage/llimage.h
@@ -276,7 +276,6 @@ protected:
 	void setDataAndSize(U8 *data, S32 width, S32 height, S8 components) ;
 
 public:
-	static S32 sGlobalRawMemory;
 	static S32 sRawImageCount;
 
 private:
diff --git a/indra/llimage/llimagej2c.cpp b/indra/llimage/llimagej2c.cpp
index e1809dbe59..8dba1641a6 100644
--- a/indra/llimage/llimagej2c.cpp
+++ b/indra/llimage/llimagej2c.cpp
@@ -146,6 +146,7 @@ bool LLImageJ2C::initEncode(LLImageRaw &raw_image, int blocks_size, int precinct
 
 bool LLImageJ2C::decode(LLImageRaw *raw_imagep, F32 decode_time)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	return decodeChannels(raw_imagep, decode_time, 0, 4);
 }
 
@@ -153,6 +154,7 @@ bool LLImageJ2C::decode(LLImageRaw *raw_imagep, F32 decode_time)
 // Returns true to mean done, whether successful or not.
 bool LLImageJ2C::decodeChannels(LLImageRaw *raw_imagep, F32 decode_time, S32 first_channel, S32 max_channel_count )
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	LLTimer elapsed;
 
 	bool res = true;
diff --git a/indra/llimage/llimageworker.cpp b/indra/llimage/llimageworker.cpp
index 0dbb744bcf..0093958e6d 100644
--- a/indra/llimage/llimageworker.cpp
+++ b/indra/llimage/llimageworker.cpp
@@ -28,64 +28,88 @@
 
 #include "llimageworker.h"
 #include "llimagedxt.h"
+#include "threadpool.h"
+
+/*--------------------------------------------------------------------------*/
+class ImageRequest
+{
+public:
+	ImageRequest(const LLPointer<LLImageFormatted>& image,
+				 S32 discard, BOOL needs_aux,
+				 const LLPointer<LLImageDecodeThread::Responder>& responder);
+	virtual ~ImageRequest();
+
+	/*virtual*/ bool processRequest();
+	/*virtual*/ void finishRequest(bool completed);
+
+private:
+	// LLPointers stored in ImageRequest MUST be LLPointer instances rather
+	// than references: we need to increment the refcount when storing these.
+	// input
+	LLPointer<LLImageFormatted> mFormattedImage;
+	S32 mDiscardLevel;
+	BOOL mNeedsAux;
+	// output
+	LLPointer<LLImageRaw> mDecodedImageRaw;
+	LLPointer<LLImageRaw> mDecodedImageAux;
+	BOOL mDecodedRaw;
+	BOOL mDecodedAux;
+	LLPointer<LLImageDecodeThread::Responder> mResponder;
+};
+
 
 //----------------------------------------------------------------------------
 
 // MAIN THREAD
-LLImageDecodeThread::LLImageDecodeThread(bool threaded)
-	: LLQueuedThread("imagedecode", threaded)
+LLImageDecodeThread::LLImageDecodeThread(bool /*threaded*/)
 {
-	mCreationMutex = new LLMutex();
+    mThreadPool.reset(new LL::ThreadPool("ImageDecode", 8));
+    mThreadPool->start();
 }
 
 //virtual 
 LLImageDecodeThread::~LLImageDecodeThread()
-{
-	delete mCreationMutex ;
-}
+{}
 
 // MAIN THREAD
 // virtual
 S32 LLImageDecodeThread::update(F32 max_time_ms)
 {
     LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
-	LLMutexLock lock(mCreationMutex);
-	for (creation_list_t::iterator iter = mCreationList.begin();
-		 iter != mCreationList.end(); ++iter)
-	{
-		creation_info& info = *iter;
-		ImageRequest* req = new ImageRequest(info.handle, info.image,
-						     info.priority, info.discard, info.needs_aux,
-						     info.responder);
+    return getPending();
+}
 
-		bool res = addRequest(req);
-		if (!res)
-		{
-			LL_ERRS() << "request added after LLLFSThread::cleanupClass()" << LL_ENDL;
-		}
-	}
-	mCreationList.clear();
-	S32 res = LLQueuedThread::update(max_time_ms);
-	return res;
+S32 LLImageDecodeThread::getPending()
+{
+    return mThreadPool->getQueue().size();
 }
 
-LLImageDecodeThread::handle_t LLImageDecodeThread::decodeImage(LLImageFormatted* image, 
-	U32 priority, S32 discard, BOOL needs_aux, Responder* responder)
+LLImageDecodeThread::handle_t LLImageDecodeThread::decodeImage(
+    const LLPointer<LLImageFormatted>& image, 
+    S32 discard,
+    BOOL needs_aux,
+    const LLPointer<LLImageDecodeThread::Responder>& responder)
 {
     LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
-	LLMutexLock lock(mCreationMutex);
-	handle_t handle = generateHandle();
-	mCreationList.push_back(creation_info(handle, image, priority, discard, needs_aux, responder));
-	return handle;
+
+    // Instantiate the ImageRequest right in the lambda, why not?
+    mThreadPool->getQueue().post(
+        [req = ImageRequest(image, discard, needs_aux, responder)]
+        () mutable
+        {
+            auto done = req.processRequest();
+            req.finishRequest(done);
+        });
+
+    // It's important to our consumer (LLTextureFetchWorker) that we return a
+    // nonzero handle. It is NOT important that the nonzero handle be unique:
+    // nothing is ever done with it except to compare it to zero, or zero it.
+    return 17;
 }
 
-// Used by unit test only
-// Returns the size of the mutex guarded list as an indication of sanity
-S32 LLImageDecodeThread::tut_size()
+void LLImageDecodeThread::shutdown()
 {
-	LLMutexLock lock(mCreationMutex);
-	S32 res = mCreationList.size();
-	return res;
+    mThreadPool->close();
 }
 
 LLImageDecodeThread::Responder::~Responder()
@@ -94,11 +118,10 @@ LLImageDecodeThread::Responder::~Responder()
 
 //----------------------------------------------------------------------------
 
-LLImageDecodeThread::ImageRequest::ImageRequest(handle_t handle, LLImageFormatted* image, 
-												U32 priority, S32 discard, BOOL needs_aux,
-												LLImageDecodeThread::Responder* responder)
-	: LLQueuedThread::QueuedRequest(handle, priority, FLAG_AUTO_COMPLETE),
-	  mFormattedImage(image),
+ImageRequest::ImageRequest(const LLPointer<LLImageFormatted>& image, 
+							S32 discard, BOOL needs_aux,
+							const LLPointer<LLImageDecodeThread::Responder>& responder)
+	: mFormattedImage(image),
 	  mDiscardLevel(discard),
 	  mNeedsAux(needs_aux),
 	  mDecodedRaw(FALSE),
@@ -107,7 +130,7 @@ LLImageDecodeThread::ImageRequest::ImageRequest(handle_t handle, LLImageFormatte
 {
 }
 
-LLImageDecodeThread::ImageRequest::~ImageRequest()
+ImageRequest::~ImageRequest()
 {
 	mDecodedImageRaw = NULL;
 	mDecodedImageAux = NULL;
@@ -118,10 +141,10 @@ LLImageDecodeThread::ImageRequest::~ImageRequest()
 
 
 // Returns true when done, whether or not decode was successful.
-bool LLImageDecodeThread::ImageRequest::processRequest()
+bool ImageRequest::processRequest()
 {
     LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
-	const F32 decode_time_slice = .1f;
+	const F32 decode_time_slice = 0.f; //disable time slicing
 	bool done = true;
 	if (!mDecodedRaw && mFormattedImage.notNull())
 	{
@@ -145,7 +168,7 @@ bool LLImageDecodeThread::ImageRequest::processRequest()
 											  mFormattedImage->getHeight(),
 											  mFormattedImage->getComponents());
 		}
-		done = mFormattedImage->decode(mDecodedImageRaw, decode_time_slice); // 1ms
+		done = mFormattedImage->decode(mDecodedImageRaw, decode_time_slice);
 		// some decoders are removing data when task is complete and there were errors
 		mDecodedRaw = done && mDecodedImageRaw->getData();
 	}
@@ -158,14 +181,14 @@ bool LLImageDecodeThread::ImageRequest::processRequest()
 											  mFormattedImage->getHeight(),
 											  1);
 		}
-		done = mFormattedImage->decodeChannels(mDecodedImageAux, decode_time_slice, 4, 4); // 1ms
+		done = mFormattedImage->decodeChannels(mDecodedImageAux, decode_time_slice, 4, 4);
 		mDecodedAux = done && mDecodedImageAux->getData();
 	}
 
 	return done;
 }
 
-void LLImageDecodeThread::ImageRequest::finishRequest(bool completed)
+void ImageRequest::finishRequest(bool completed)
 {
     LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	if (mResponder.notNull())
@@ -175,10 +198,3 @@ void LLImageDecodeThread::ImageRequest::finishRequest(bool completed)
 	}
 	// Will automatically be deleted
 }
-
-// Used by unit test only
-// Checks that a responder exists for this instance so that something can happen when completion is reached
-bool LLImageDecodeThread::ImageRequest::tut_isOK()
-{
-	return mResponder.notNull();
-}
diff --git a/indra/llimage/llimageworker.h b/indra/llimage/llimageworker.h
index 1bfb0ddfd3..18398d9ae2 100644
--- a/indra/llimage/llimageworker.h
+++ b/indra/llimage/llimageworker.h
@@ -29,9 +29,13 @@
 
 #include "llimage.h"
 #include "llpointer.h"
-#include "llworkerthread.h"
 
-class LLImageDecodeThread : public LLQueuedThread
+namespace LL
+{
+    class ThreadPool;
+} // namespace LL
+
+class LLImageDecodeThread
 {
 public:
 	class Responder : public LLThreadSafeRefCount
@@ -42,63 +46,24 @@ public:
 		virtual void completed(bool success, LLImageRaw* raw, LLImageRaw* aux) = 0;
 	};
 
-	class ImageRequest : public LLQueuedThread::QueuedRequest
-	{
-	protected:
-		virtual ~ImageRequest(); // use deleteRequest()
-		
-	public:
-		ImageRequest(handle_t handle, LLImageFormatted* image,
-					 U32 priority, S32 discard, BOOL needs_aux,
-					 LLImageDecodeThread::Responder* responder);
-
-		/*virtual*/ bool processRequest();
-		/*virtual*/ void finishRequest(bool completed);
-
-		// Used by unit tests to check the consitency of the request instance
-		bool tut_isOK();
-		
-	private:
-		// input
-		LLPointer<LLImageFormatted> mFormattedImage;
-		S32 mDiscardLevel;
-		BOOL mNeedsAux;
-		// output
-		LLPointer<LLImageRaw> mDecodedImageRaw;
-		LLPointer<LLImageRaw> mDecodedImageAux;
-		BOOL mDecodedRaw;
-		BOOL mDecodedAux;
-		LLPointer<LLImageDecodeThread::Responder> mResponder;
-	};
-	
 public:
 	LLImageDecodeThread(bool threaded = true);
 	virtual ~LLImageDecodeThread();
 
-	handle_t decodeImage(LLImageFormatted* image,
-						 U32 priority, S32 discard, BOOL needs_aux,
-						 Responder* responder);
+	// meant to resemble LLQueuedThread::handle_t
+	typedef U32 handle_t;
+	handle_t decodeImage(const LLPointer<LLImageFormatted>& image,
+						 S32 discard, BOOL needs_aux,
+						 const LLPointer<Responder>& responder);
+	S32 getPending();
 	S32 update(F32 max_time_ms);
+	void shutdown();
 
-	// Used by unit tests to check the consistency of the thread instance
-	S32 tut_size();
-	
 private:
-	struct creation_info
-	{
-		handle_t handle;
-		LLPointer<LLImageFormatted> image;
-		U32 priority;
-		S32 discard;
-		BOOL needs_aux;
-		LLPointer<Responder> responder;
-		creation_info(handle_t h, LLImageFormatted* i, U32 p, S32 d, BOOL aux, Responder* r)
-			: handle(h), image(i), priority(p), discard(d), needs_aux(aux), responder(r)
-		{}
-	};
-	typedef std::list<creation_info> creation_list_t;
-	creation_list_t mCreationList;
-	LLMutex* mCreationMutex;
+	// As of SL-17483, LLImageDecodeThread is no longer itself an
+	// LLQueuedThread - instead this is the API by which we submit work to the
+	// "ImageDecode" ThreadPool.
+	std::unique_ptr<LL::ThreadPool> mThreadPool;
 };
 
 #endif
diff --git a/indra/llimage/tests/llimageworker_test.cpp b/indra/llimage/tests/llimageworker_test.cpp
index 9011ac615c..0a97b739b0 100644
--- a/indra/llimage/tests/llimageworker_test.cpp
+++ b/indra/llimage/tests/llimageworker_test.cpp
@@ -125,42 +125,11 @@ namespace tut
 		}
 	};
 
-	// Test wrapper declaration : image worker
-	// Note: this class is not meant to be instantiated outside an LLImageDecodeThread instance
-	// but it's not a bad idea to get its public API a good shake as part of a thorough unit test set.
-	// Some gotcha with the destructor though (see below).
-	struct imagerequest_test
-	{
-		// Instance to be tested
-		LLImageDecodeThread::ImageRequest* mRequest;
-		bool done;
-
-		// Constructor and destructor of the test wrapper
-		imagerequest_test()
-		{
-			done = false;
-
-			mRequest = new LLImageDecodeThread::ImageRequest(0, 0,
-											 LLQueuedThread::PRIORITY_NORMAL, 0, FALSE,
-											 new responder_test(&done));
-		}
-		~imagerequest_test()
-		{
-			// We should delete the object *but*, because its destructor is protected, that cannot be
-			// done from outside an LLImageDecodeThread instance... So we leak memory here... It's fine...
-			//delete mRequest;
-		}
-	};
-
 	// Tut templating thingamagic: test group, object and test instance
 	typedef test_group<imagedecodethread_test> imagedecodethread_t;
 	typedef imagedecodethread_t::object imagedecodethread_object_t;
 	tut::imagedecodethread_t tut_imagedecodethread("LLImageDecodeThread");
 
-	typedef test_group<imagerequest_test> imagerequest_t;
-	typedef imagerequest_t::object imagerequest_object_t;
-	tut::imagerequest_t tut_imagerequest("LLImageRequest");
-
 	// ---------------------------------------------------------------------------------------
 	// Test functions
 	// Notes:
@@ -172,64 +141,18 @@ namespace tut
 	// ---------------------------------------------------------------------------------------
 	// Test the LLImageDecodeThread interface
 	// ---------------------------------------------------------------------------------------
-	//
-	// Note on Unit Testing Queued Thread Classes
-	//
-	// Since methods on such a class are called on a separate loop and that we can't insert tut
-	// ensure() calls in there, we exercise the class with 2 sets of tests:
-	// - 1: Test as a single threaded instance: We declare the class but ask for no thread
-	//   to be spawned (easy with LLThreads since there's a boolean argument on the constructor
-	//   just for that). We can then unit test each public method like we do on a normal class.
-	// - 2: Test as a threaded instance: We let the thread launch and check that its external 
-	//   behavior is as expected (i.e. it runs, can accept a work order and processes
-	//   it). Typically though there's no guarantee that this exercises all the methods of the
-	//   class which is why we also need the previous "non threaded" set of unit tests for
-	//   complete coverage.
-	//
-	// ---------------------------------------------------------------------------------------
 
 	template<> template<>
 	void imagedecodethread_object_t::test<1>()
 	{
-		// Test a *non threaded* instance of the class
-		mThread = new LLImageDecodeThread(false);
-		ensure("LLImageDecodeThread: non threaded constructor failed", mThread != NULL);
-		// Test that we start with an empty list right at creation
-		ensure("LLImageDecodeThread: non threaded init state incorrect", mThread->tut_size() == 0);
-		// Insert something in the queue
-		bool done = false;
-		LLImageDecodeThread::handle_t decodeHandle = mThread->decodeImage(NULL, LLQueuedThread::PRIORITY_NORMAL, 0, FALSE, new responder_test(&done));
-		// Verifies we got a valid handle
-		ensure("LLImageDecodeThread: non threaded decodeImage(), returned handle is null", decodeHandle != 0);
-		// Verifies that we do now have something in the queued list
-		ensure("LLImageDecodeThread: non threaded decodeImage() insertion in threaded list failed", mThread->tut_size() == 1);
-		// Trigger queue handling "manually" (on a threaded instance, this is done on the thread loop)
-		S32 res = mThread->update(0);
-		// Verifies that we successfully handled the list
-		ensure("LLImageDecodeThread: non threaded update() list handling test failed", res == 0);
-		// Verifies that the list is now empty
-		ensure("LLImageDecodeThread: non threaded update() list emptying test failed", mThread->tut_size() == 0);
-	}
-
-	template<> template<>
-	void imagedecodethread_object_t::test<2>()
-	{
 		// Test a *threaded* instance of the class
 		mThread = new LLImageDecodeThread(true);
 		ensure("LLImageDecodeThread: threaded constructor failed", mThread != NULL);
-		// Test that we start with an empty list right at creation
-		ensure("LLImageDecodeThread: threaded init state incorrect", mThread->tut_size() == 0);
 		// Insert something in the queue
 		bool done = false;
-		LLImageDecodeThread::handle_t decodeHandle = mThread->decodeImage(NULL, LLQueuedThread::PRIORITY_NORMAL, 0, FALSE, new responder_test(&done));
+		LLImageDecodeThread::handle_t decodeHandle = mThread->decodeImage(NULL, 0, FALSE, new responder_test(&done));
 		// Verifies we get back a valid handle
 		ensure("LLImageDecodeThread:  threaded decodeImage(), returned handle is null", decodeHandle != 0);
-		// Wait a little so to simulate the main thread doing something on its main loop...
-		ms_sleep(500);		// 500 milliseconds
-		// Verifies that the responder has *not* been called yet in the meantime
-		ensure("LLImageDecodeThread: responder creation failed", done == false);
-		// Ask the thread to update: that means tells the queue to check itself and creates work requests
-		mThread->update(1);
 		// Wait till the thread has time to handle the work order (though it doesn't do much per work order...)
 		const U32 INCREMENT_TIME = 500;				// 500 milliseconds
 		const U32 MAX_TIME = 20 * INCREMENT_TIME;	// Do the loop 20 times max, i.e. wait 10 seconds but no more
@@ -242,24 +165,4 @@ namespace tut
 		// Verifies that the responder has now been called
 		ensure("LLImageDecodeThread: threaded work unit not processed", done == true);
 	}
-
-	// ---------------------------------------------------------------------------------------
-	// Test the LLImageDecodeThread::ImageRequest interface
-	// ---------------------------------------------------------------------------------------
-	
-	template<> template<>
-	void imagerequest_object_t::test<1>()
-	{
-		// Test that we start with a correct request at creation
-		ensure("LLImageDecodeThread::ImageRequest::ImageRequest() constructor test failed", mRequest->tut_isOK());
-		bool res = mRequest->processRequest();
-		// Verifies that we processed the request successfully
-		ensure("LLImageDecodeThread::ImageRequest::processRequest() processing request test failed", res == true);
-		// Check that we can call the finishing call safely
-		try {
-			mRequest->finishRequest(false);
-		} catch (...) {
-			fail("LLImageDecodeThread::ImageRequest::finishRequest() test failed");
-		}
-	}
 }
diff --git a/indra/llimagej2coj/llimagej2coj.cpp b/indra/llimagej2coj/llimagej2coj.cpp
index 925da5674b..8a641617fa 100644
--- a/indra/llimagej2coj/llimagej2coj.cpp
+++ b/indra/llimagej2coj/llimagej2coj.cpp
@@ -118,6 +118,7 @@ bool LLImageJ2COJ::initEncode(LLImageJ2C &base, LLImageRaw &raw_image, int block
 
 bool LLImageJ2COJ::decodeImpl(LLImageJ2C &base, LLImageRaw &raw_image, F32 decode_time, S32 first_channel, S32 max_channel_count)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	//
 	// FIXME: Get the comment field out of the texture
 	//
diff --git a/indra/llkdu/llimagej2ckdu.cpp b/indra/llkdu/llimagej2ckdu.cpp
index dac5349f57..2ad42d6b87 100644
--- a/indra/llkdu/llimagej2ckdu.cpp
+++ b/indra/llkdu/llimagej2ckdu.cpp
@@ -379,6 +379,7 @@ void LLImageJ2CKDU::setupCodeStream(LLImageJ2C &base, bool keep_codestream, ECod
 
 void LLImageJ2CKDU::cleanupCodeStream()
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	mInputp.reset();
 	mDecodeState.reset();
 	mCodeStreamp.reset();
@@ -426,6 +427,7 @@ bool LLImageJ2CKDU::initEncode(LLImageJ2C &base, LLImageRaw &raw_image, int bloc
 // decodeImpl() usage matters for production.
 bool LLImageJ2CKDU::initDecode(LLImageJ2C &base, LLImageRaw &raw_image, F32 decode_time, ECodeStreamMode mode, S32 first_channel, S32 max_channel_count, int discard_level, int* region)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	base.resetLastError();
 
 	// *FIX: kdu calls our callback function if there's an error, and then bombs.
@@ -509,6 +511,7 @@ bool LLImageJ2CKDU::initDecode(LLImageJ2C &base, LLImageRaw &raw_image, F32 deco
 // Returns true to mean done, whether successful or not.
 bool LLImageJ2CKDU::decodeImpl(LLImageJ2C &base, LLImageRaw &raw_image, F32 decode_time, S32 first_channel, S32 max_channel_count)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	ECodeStreamMode mode = MODE_FAST;
 
 	LLTimer decode_timer;
@@ -1332,6 +1335,7 @@ the `buf' pointer may actually point into a larger buffer representing
 multiple tiles.  For this reason, `row_gap' is needed to identify the
 separation between consecutive rows in the real buffer. */
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	S32 c;
 	// Now walk through the lines of the buffer, recovering them from the
 	// relevant tile-component processing engines.
@@ -1339,18 +1343,27 @@ separation between consecutive rows in the real buffer. */
 	LLTimer decode_timer;
 	while (mDims.size.y--)
 	{
-		for (c = 0; c < mNumComponents; c++)
-		{
-			mEngines[c].pull(mLines[c]);
-		}
+        {
+            LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("kduptc - pull");
+            for (c = 0; c < mNumComponents; c++)
+            {
+                mEngines[c].pull(mLines[c]);
+            }
+        }
+
 		if ((mNumComponents >= 3) && mUseYCC)
 		{
+            LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("kduptc - convert");
 			kdu_convert_ycc_to_rgb(mLines[0],mLines[1],mLines[2]);
 		}
-		for (c = 0; c < mNumComponents; c++)
-		{
-			transfer_bytes(mBuf+c,mLines[c],mNumComponents,mBitDepths[c]);
-		}
+
+        {
+            LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("kduptc - transfer");
+            for (c = 0; c < mNumComponents; c++)
+            {
+                transfer_bytes(mBuf + c, mLines[c], mNumComponents, mBitDepths[c]);
+            }
+        }
 		mBuf += mRowGap;
 		if (mDims.size.y % 10)
 		{
diff --git a/indra/llmessage/llavatarnamecache.cpp b/indra/llmessage/llavatarnamecache.cpp
index c67f59bc0c..ae066112c1 100644
--- a/indra/llmessage/llavatarnamecache.cpp
+++ b/indra/llmessage/llavatarnamecache.cpp
@@ -64,7 +64,6 @@ LLCore::HttpRequest::ptr_t		sHttpRequest;
 LLCore::HttpHeaders::ptr_t		sHttpHeaders;
 LLCore::HttpOptions::ptr_t		sHttpOptions;
 LLCore::HttpRequest::policy_t	sHttpPolicy;
-LLCore::HttpRequest::priority_t	sHttpPriority;
 
 /* Sample response:
 <?xml version="1.0"?>
@@ -121,7 +120,6 @@ LLAvatarNameCache::LLAvatarNameCache()
     sHttpHeaders = LLCore::HttpHeaders::ptr_t(new LLCore::HttpHeaders());
     sHttpOptions = LLCore::HttpOptions::ptr_t(new LLCore::HttpOptions());
     sHttpPolicy = LLCore::HttpRequest::DEFAULT_POLICY_ID;
-    sHttpPriority = 0;
 }
 
 LLAvatarNameCache::~LLAvatarNameCache()
diff --git a/indra/llmessage/llcorehttputil.cpp b/indra/llmessage/llcorehttputil.cpp
index 7031f1aa8c..96af8bacee 100644
--- a/indra/llmessage/llcorehttputil.cpp
+++ b/indra/llmessage/llcorehttputil.cpp
@@ -131,7 +131,6 @@ bool responseToLLSD(HttpResponse * response, bool log, LLSD & out_llsd)
 
 HttpHandle requestPostWithLLSD(HttpRequest * request,
     HttpRequest::policy_t policy_id,
-    HttpRequest::priority_t priority,
     const std::string & url,
     const LLSD & body,
     const HttpOptions::ptr_t &options,
@@ -145,7 +144,6 @@ HttpHandle requestPostWithLLSD(HttpRequest * request,
     LLSDSerialize::toXML(body, bas);
 
     handle = request->requestPost(policy_id,
-        priority,
         url,
         ba,
         options,
@@ -158,7 +156,6 @@ HttpHandle requestPostWithLLSD(HttpRequest * request,
 
 HttpHandle requestPutWithLLSD(HttpRequest * request,
     HttpRequest::policy_t policy_id,
-    HttpRequest::priority_t priority,
     const std::string & url,
     const LLSD & body,
     const HttpOptions::ptr_t &options,
@@ -172,7 +169,6 @@ HttpHandle requestPutWithLLSD(HttpRequest * request,
     LLSDSerialize::toXML(body, bas);
 
     handle = request->requestPut(policy_id,
-        priority,
         url,
         ba,
         options,
@@ -184,7 +180,6 @@ HttpHandle requestPutWithLLSD(HttpRequest * request,
 
 HttpHandle requestPatchWithLLSD(HttpRequest * request,
     HttpRequest::policy_t policy_id,
-    HttpRequest::priority_t priority,
     const std::string & url,
     const LLSD & body,
     const HttpOptions::ptr_t &options,
@@ -198,7 +193,6 @@ HttpHandle requestPatchWithLLSD(HttpRequest * request,
     LLSDSerialize::toXML(body, bas);
 
     handle = request->requestPatch(policy_id,
-        priority,
         url,
         ba,
         options,
@@ -672,10 +666,9 @@ const std::string HttpCoroutineAdapter::HTTP_RESULTS_CONTENT("content");
 const std::string HttpCoroutineAdapter::HTTP_RESULTS_RAW("raw");
 
 HttpCoroutineAdapter::HttpCoroutineAdapter(const std::string &name,
-    LLCore::HttpRequest::policy_t policyId, LLCore::HttpRequest::priority_t priority) :
+    LLCore::HttpRequest::policy_t policyId) :
     mAdapterName(name),
     mPolicyId(policyId),
-    mPriority(priority),
     mYieldingHandle(LLCORE_HTTP_HANDLE_INVALID),
     mWeakRequest(),
     mWeakHandler()
@@ -709,7 +702,7 @@ LLSD HttpCoroutineAdapter::postAndSuspend_(LLCore::HttpRequest::ptr_t &request,
     // The HTTPCoroHandler does not self delete, so retrieval of a the contained 
     // pointer from the smart pointer is safe in this case.
     LLCore::HttpHandle hhandle = requestPostWithLLSD(request,
-        mPolicyId, mPriority, url, body, options, headers,
+        mPolicyId, url, body, options, headers,
         handler);
 
     if (hhandle == LLCORE_HTTP_HANDLE_INVALID)
@@ -832,7 +825,7 @@ LLSD HttpCoroutineAdapter::postAndSuspend_(LLCore::HttpRequest::ptr_t &request,
 
     // The HTTPCoroHandler does not self delete, so retrieval of a the contained 
     // pointer from the smart pointer is safe in this case.
-    LLCore::HttpHandle hhandle = request->requestPost(mPolicyId, mPriority, url, rawbody.get(),
+    LLCore::HttpHandle hhandle = request->requestPost(mPolicyId, url, rawbody.get(),
         options, headers, handler);
 
     if (hhandle == LLCORE_HTTP_HANDLE_INVALID)
@@ -890,7 +883,7 @@ LLSD HttpCoroutineAdapter::putAndSuspend_(LLCore::HttpRequest::ptr_t &request,
     // The HTTPCoroHandler does not self delete, so retrieval of a the contained 
     // pointer from the smart pointer is safe in this case.
     LLCore::HttpHandle hhandle = requestPutWithLLSD(request,
-        mPolicyId, mPriority, url, body, options, headers,
+        mPolicyId, url, body, options, headers,
         handler);
 
     if (hhandle == LLCORE_HTTP_HANDLE_INVALID)
@@ -916,7 +909,7 @@ LLSD HttpCoroutineAdapter::putAndSuspend_(LLCore::HttpRequest::ptr_t &request,
 
     // The HTTPCoroHandler does not self delete, so retrieval of a the contained 
     // pointer from the smart pointer is safe in this case.
-    LLCore::HttpHandle hhandle = request->requestPut(mPolicyId, mPriority, 
+    LLCore::HttpHandle hhandle = request->requestPut(mPolicyId,
         url, rawbody.get(), options, headers, handler);
 
     if (hhandle == LLCORE_HTTP_HANDLE_INVALID)
@@ -972,7 +965,7 @@ LLSD HttpCoroutineAdapter::getAndSuspend_(LLCore::HttpRequest::ptr_t &request,
 
     // The HTTPCoroHandler does not self delete, so retrieval of a the contained 
     // pointer from the smart pointer is safe in this case.
-    LLCore::HttpHandle hhandle = request->requestGet(mPolicyId, mPriority,
+    LLCore::HttpHandle hhandle = request->requestGet(mPolicyId,
         url, options, headers, handler);
 
     if (hhandle == LLCORE_HTTP_HANDLE_INVALID)
@@ -1018,7 +1011,7 @@ LLSD HttpCoroutineAdapter::deleteAndSuspend_(LLCore::HttpRequest::ptr_t &request
     checkDefaultHeaders(headers);
     // The HTTPCoroHandler does not self delete, so retrieval of a the contained 
     // pointer from the smart pointer is safe in this case.
-    LLCore::HttpHandle hhandle = request->requestDelete(mPolicyId, mPriority,
+    LLCore::HttpHandle hhandle = request->requestDelete(mPolicyId,
         url, options, headers, handler);
 
     if (hhandle == LLCORE_HTTP_HANDLE_INVALID)
@@ -1056,7 +1049,7 @@ LLSD HttpCoroutineAdapter::patchAndSuspend_(LLCore::HttpRequest::ptr_t &request,
     // The HTTPCoroHandler does not self delete, so retrieval of a the contained 
     // pointer from the smart pointer is safe in this case.
     LLCore::HttpHandle hhandle = requestPatchWithLLSD(request,
-        mPolicyId, mPriority, url, body, options, headers,
+        mPolicyId, url, body, options, headers,
         handler);
 
     if (hhandle == LLCORE_HTTP_HANDLE_INVALID)
@@ -1098,7 +1091,7 @@ LLSD HttpCoroutineAdapter::copyAndSuspend_(LLCore::HttpRequest::ptr_t &request,
     // The HTTPCoroHandler does not self delete, so retrieval of a the contained 
     // pointer from the smart pointer is safe in this case.
     // 
-    LLCore::HttpHandle hhandle = request->requestCopy(mPolicyId, mPriority, url,
+    LLCore::HttpHandle hhandle = request->requestCopy(mPolicyId, url,
         options, headers, handler);
 
     if (hhandle == LLCORE_HTTP_HANDLE_INVALID)
@@ -1140,7 +1133,7 @@ LLSD HttpCoroutineAdapter::moveAndSuspend_(LLCore::HttpRequest::ptr_t &request,
     // The HTTPCoroHandler does not self delete, so retrieval of a the contained 
     // pointer from the smart pointer is safe in this case.
     // 
-    LLCore::HttpHandle hhandle = request->requestMove(mPolicyId, mPriority, url,
+    LLCore::HttpHandle hhandle = request->requestMove(mPolicyId, url,
         options, headers, handler);
 
     if (hhandle == LLCORE_HTTP_HANDLE_INVALID)
diff --git a/indra/llmessage/llcorehttputil.h b/indra/llmessage/llcorehttputil.h
index 6f0b865f83..430dc417ac 100644
--- a/indra/llmessage/llcorehttputil.h
+++ b/indra/llmessage/llcorehttputil.h
@@ -116,7 +116,6 @@ std::string responseToString(LLCore::HttpResponse * response);
 ///
 LLCore::HttpHandle requestPostWithLLSD(LLCore::HttpRequest * request,
     LLCore::HttpRequest::policy_t policy_id,
-    LLCore::HttpRequest::priority_t priority,
     const std::string & url,
     const LLSD & body,
     const LLCore::HttpOptions::ptr_t &options,
@@ -125,20 +124,18 @@ LLCore::HttpHandle requestPostWithLLSD(LLCore::HttpRequest * request,
 
 inline LLCore::HttpHandle requestPostWithLLSD(LLCore::HttpRequest::ptr_t & request,
 	LLCore::HttpRequest::policy_t policy_id,
-	LLCore::HttpRequest::priority_t priority,
 	const std::string & url,
 	const LLSD & body,
 	const LLCore::HttpOptions::ptr_t & options,
 	const LLCore::HttpHeaders::ptr_t & headers,
     const LLCore::HttpHandler::ptr_t & handler)
 {
-    return requestPostWithLLSD(request.get(), policy_id, priority,
+    return requestPostWithLLSD(request.get(), policy_id,
         url, body, options, headers, handler);
 }
 
 inline LLCore::HttpHandle requestPostWithLLSD(LLCore::HttpRequest::ptr_t & request,
     LLCore::HttpRequest::policy_t policy_id,
-    LLCore::HttpRequest::priority_t priority,
     const std::string & url,
     const LLSD & body,
     const LLCore::HttpHandler::ptr_t &handler)
@@ -146,7 +143,7 @@ inline LLCore::HttpHandle requestPostWithLLSD(LLCore::HttpRequest::ptr_t & reque
     LLCore::HttpOptions::ptr_t options;
     LLCore::HttpHeaders::ptr_t headers;
 
-    return requestPostWithLLSD(request.get(), policy_id, priority,
+    return requestPostWithLLSD(request.get(), policy_id,
         url, body, options, headers, handler);
 }
 
@@ -169,7 +166,6 @@ inline LLCore::HttpHandle requestPostWithLLSD(LLCore::HttpRequest::ptr_t & reque
 ///
 LLCore::HttpHandle requestPutWithLLSD(LLCore::HttpRequest * request,
 	LLCore::HttpRequest::policy_t policy_id,
-	LLCore::HttpRequest::priority_t priority,
 	const std::string & url,
 	const LLSD & body,
 	const LLCore::HttpOptions::ptr_t &options,
@@ -178,20 +174,18 @@ LLCore::HttpHandle requestPutWithLLSD(LLCore::HttpRequest * request,
 
 inline LLCore::HttpHandle requestPutWithLLSD(LLCore::HttpRequest::ptr_t & request,
 	LLCore::HttpRequest::policy_t policy_id,
-	LLCore::HttpRequest::priority_t priority,
 	const std::string & url,
 	const LLSD & body,
 	const LLCore::HttpOptions::ptr_t & options,
 	const LLCore::HttpHeaders::ptr_t & headers,
     LLCore::HttpHandler::ptr_t handler)
 {
-    return requestPutWithLLSD(request.get(), policy_id, priority,
+    return requestPutWithLLSD(request.get(), policy_id,
         url, body, options, headers, handler);
 }
 
 inline LLCore::HttpHandle requestPutWithLLSD(LLCore::HttpRequest::ptr_t & request,
     LLCore::HttpRequest::policy_t policy_id,
-    LLCore::HttpRequest::priority_t priority,
     const std::string & url,
     const LLSD & body,
     LLCore::HttpHandler::ptr_t handler)
@@ -199,7 +193,7 @@ inline LLCore::HttpHandle requestPutWithLLSD(LLCore::HttpRequest::ptr_t & reques
     LLCore::HttpOptions::ptr_t options;
     LLCore::HttpHeaders::ptr_t headers;
 
-    return requestPutWithLLSD(request.get(), policy_id, priority,
+    return requestPutWithLLSD(request.get(), policy_id,
         url, body, options, headers, handler);
 }
 
@@ -221,7 +215,6 @@ inline LLCore::HttpHandle requestPutWithLLSD(LLCore::HttpRequest::ptr_t & reques
 ///
 LLCore::HttpHandle requestPatchWithLLSD(LLCore::HttpRequest * request,
     LLCore::HttpRequest::policy_t policy_id,
-    LLCore::HttpRequest::priority_t priority,
     const std::string & url,
     const LLSD & body,
     const LLCore::HttpOptions::ptr_t &options,
@@ -230,20 +223,18 @@ LLCore::HttpHandle requestPatchWithLLSD(LLCore::HttpRequest * request,
 
 inline LLCore::HttpHandle requestPatchWithLLSD(LLCore::HttpRequest::ptr_t & request,
     LLCore::HttpRequest::policy_t policy_id,
-    LLCore::HttpRequest::priority_t priority,
     const std::string & url,
     const LLSD & body,
     const LLCore::HttpOptions::ptr_t & options,
     const LLCore::HttpHeaders::ptr_t & headers,
     const LLCore::HttpHandler::ptr_t & handler)
 {
-    return requestPatchWithLLSD(request.get(), policy_id, priority,
+    return requestPatchWithLLSD(request.get(), policy_id,
         url, body, options, headers, handler);
 }
 
 inline LLCore::HttpHandle requestPatchWithLLSD(LLCore::HttpRequest::ptr_t & request,
     LLCore::HttpRequest::policy_t policy_id,
-    LLCore::HttpRequest::priority_t priority,
     const std::string & url,
     const LLSD & body,
     const LLCore::HttpHandler::ptr_t &handler)
@@ -251,7 +242,7 @@ inline LLCore::HttpHandle requestPatchWithLLSD(LLCore::HttpRequest::ptr_t & requ
     LLCore::HttpOptions::ptr_t options;
     LLCore::HttpHeaders::ptr_t headers;
 
-    return requestPatchWithLLSD(request.get(), policy_id, priority,
+    return requestPatchWithLLSD(request.get(), policy_id,
         url, body, options, headers, handler);
 }
 
@@ -329,8 +320,7 @@ public:
     typedef boost::shared_ptr<HttpCoroutineAdapter> ptr_t;
     typedef boost::weak_ptr<HttpCoroutineAdapter>   wptr_t;
 
-    HttpCoroutineAdapter(const std::string &name, LLCore::HttpRequest::policy_t policyId,
-        LLCore::HttpRequest::priority_t priority = 0L);
+    HttpCoroutineAdapter(const std::string &name, LLCore::HttpRequest::policy_t policyId);
     ~HttpCoroutineAdapter();
 
     /// Execute a Post transaction on the supplied URL and yield execution of 
@@ -673,7 +663,6 @@ private:
     void checkDefaultHeaders(LLCore::HttpHeaders::ptr_t &headers);
 
     std::string                     mAdapterName;
-    LLCore::HttpRequest::priority_t mPriority;
     LLCore::HttpRequest::policy_t   mPolicyId;
 
     LLCore::HttpHandle              mYieldingHandle;
diff --git a/indra/llmessage/tests/llcoproceduremanager_test.cpp b/indra/llmessage/tests/llcoproceduremanager_test.cpp
index 6424117ef3..78424a28c8 100644
--- a/indra/llmessage/tests/llcoproceduremanager_test.cpp
+++ b/indra/llmessage/tests/llcoproceduremanager_test.cpp
@@ -48,7 +48,7 @@
 #pragma warning(disable: 4702)
 #endif
 
-LLCoreHttpUtil::HttpCoroutineAdapter::HttpCoroutineAdapter(std::string const&, unsigned int, unsigned int)
+LLCoreHttpUtil::HttpCoroutineAdapter::HttpCoroutineAdapter(std::string const&, unsigned int)
 {
 }
 
diff --git a/indra/llrender/llimagegl.cpp b/indra/llrender/llimagegl.cpp
index 89dd68da76..6215727de0 100644
--- a/indra/llrender/llimagegl.cpp
+++ b/indra/llrender/llimagegl.cpp
@@ -53,13 +53,75 @@ const F32 MIN_TEXTURE_LIFETIME = 10.f;
 //assumes i is a power of 2 > 0
 U32 wpo2(U32 i);
 
+
+// texture memory accounting (for OS X)
+static LLMutex sTexMemMutex;
+static std::unordered_map<U32, U32> sTextureAllocs;
+static U64 sTextureBytes = 0;
+
+// track a texture alloc on the currently bound texture.
+// asserts that no currently tracked alloc exists
+static void alloc_tex_image(U32 width, U32 height, U32 pixformat)
+{
+    U32 texUnit = gGL.getCurrentTexUnitIndex();
+    U32 texName = gGL.getTexUnit(texUnit)->getCurrTexture();
+    S32 size = LLImageGL::dataFormatBytes(pixformat, width, height);
+
+    llassert(size >= 0);
+
+    sTexMemMutex.lock();
+    llassert(sTextureAllocs.find(texName) == sTextureAllocs.end());
+
+    sTextureAllocs[texName] = size;
+    sTextureBytes += size;
+
+    sTexMemMutex.unlock();
+}
+
+// track texture free on given texName
+static void free_tex_image(U32 texName)
+{
+    sTexMemMutex.lock();
+    auto iter = sTextureAllocs.find(texName);
+    if (iter != sTextureAllocs.end())
+    {
+        llassert(iter->second <= sTextureBytes); // sTextureBytes MUST NOT go below zero
+
+        sTextureBytes -= iter->second;
+
+        sTextureAllocs.erase(iter);
+    }
+
+    sTexMemMutex.unlock();
+}
+
+// track texture free on given texNames
+static void free_tex_images(U32 count, const U32* texNames)
+{
+    for (int i = 0; i < count; ++i)
+    {
+        free_tex_image(texNames[i]);
+    }
+}
+
+// track texture free on currently bound texture
+static void free_cur_tex_image()
+{
+    U32 texUnit = gGL.getCurrentTexUnitIndex();
+    U32 texName = gGL.getTexUnit(texUnit)->getCurrTexture();
+    free_tex_image(texName);
+}
+
+// static 
+U64 LLImageGL::getTextureBytesAllocated()
+{
+    return sTextureBytes;
+}
+
 //statics
 
 U32 LLImageGL::sUniqueCount				= 0;
 U32 LLImageGL::sBindCount				= 0;
-S32Bytes LLImageGL::sGlobalTextureMemory(0);
-S32Bytes LLImageGL::sBoundTextureMemory(0);
-S32Bytes LLImageGL::sCurBoundTextureMemory(0);
 S32 LLImageGL::sCount					= 0;
 
 BOOL LLImageGL::sGlobalUseAnisotropic	= FALSE;
@@ -220,6 +282,7 @@ S32 LLImageGL::dataFormatBits(S32 dataformat)
     case GL_RGBA:								    return 32;
     case GL_SRGB_ALPHA:						        return 32;
     case GL_BGRA:								    return 32;		// Used for QuickTime media textures on the Mac
+    case GL_DEPTH_COMPONENT:                        return 24;
     default:
         LL_ERRS() << "LLImageGL::Unknown format: " << dataformat << LL_ENDL;
         return 0;
@@ -282,15 +345,6 @@ void LLImageGL::updateStats(F32 current_time)
 {
     LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	sLastFrameTime = current_time;
-	sBoundTextureMemory = sCurBoundTextureMemory;
-	sCurBoundTextureMemory = S32Bytes(0);
-}
-
-//static
-S32 LLImageGL::updateBoundTexMem(const S32Bytes mem, const S32 ncomponents, S32 category)
-{
-	LLImageGL::sCurBoundTextureMemory += mem ;
-	return LLImageGL::sCurBoundTextureMemory.value();
 }
 
 //----------------------------------------------------------------------------
@@ -623,7 +677,7 @@ void LLImageGL::forceUpdateBindStats(void) const
 	mLastBindTime = sLastFrameTime;
 }
 
-BOOL LLImageGL::updateBindStats(S32Bytes tex_mem) const
+BOOL LLImageGL::updateBindStats() const
 {	
 	if (mTexName != 0)
 	{
@@ -635,7 +689,6 @@ BOOL LLImageGL::updateBindStats(S32Bytes tex_mem) const
 		{
 			// we haven't accounted for this texture yet this frame
 			sUniqueCount++;
-			updateBoundTexMem(tex_mem, mComponents, mCategory);
 			mLastBindTime = sLastFrameTime;
 
 			return TRUE ;
@@ -1232,6 +1285,7 @@ void LLImageGL::deleteTextures(S32 numTextures, const U32 *textures)
 {
 	if (gGLManager.mInited)
 	{
+        free_tex_images(numTextures, textures);
 		glDeleteTextures(numTextures, textures);
 	}
 }
@@ -1354,7 +1408,10 @@ void LLImageGL::setManualImage(U32 target, S32 miplevel, S32 intformat, S32 widt
     stop_glerror();
     {
         LL_PROFILE_ZONE_NAMED("glTexImage2D");
+
+        free_cur_tex_image();
         glTexImage2D(target, miplevel, intformat, width, height, 0, pixformat, pixtype, use_scratch ? scratch : pixels);
+        alloc_tex_image(width, height, pixformat);
     }
     stop_glerror();
 
@@ -1601,11 +1658,6 @@ BOOL LLImageGL::createGLTexture(S32 discard_level, const U8* data_in, BOOL data_
     // things will break if we don't unbind after creation
     gGL.getTexUnit(0)->unbind(mBindTarget);
 
-    if (old_texname != 0)
-    {
-        sGlobalTextureMemory -= mTextureMemory;
-    }
-
     //if we're on the image loading thread, be sure to delete old_texname and update mTexName on the main thread
     if (!defer_copy)
     {
@@ -1626,7 +1678,6 @@ BOOL LLImageGL::createGLTexture(S32 discard_level, const U8* data_in, BOOL data_
 
     
     mTextureMemory = (S32Bytes)getMipBytes(mCurrentDiscardLevel);
-    sGlobalTextureMemory += mTextureMemory;
     mTexelsInGLTexture = getWidth() * getHeight();
 
     // mark this as bound at this point, so we don't throw it out immediately
@@ -1636,51 +1687,6 @@ BOOL LLImageGL::createGLTexture(S32 discard_level, const U8* data_in, BOOL data_
     return TRUE;
 }
 
-void LLImageGLThread::updateClass()
-{
-    LL_PROFILE_ZONE_SCOPED;
-
-    // update available vram one per second
-    static LLFrameTimer sTimer;
-
-    if (sTimer.getElapsedSeconds() < 1.f)
-    {
-        return;
-    }
-    
-    sTimer.reset();
-
-    auto func = []()
-    {
-        if (gGLManager.mHasATIMemInfo)
-        {
-            S32 meminfo[4];
-            glGetIntegerv(GL_TEXTURE_FREE_MEMORY_ATI, meminfo);
-            LLImageGLThread::sFreeVRAMMegabytes = meminfo[0];
-
-        }
-        else if (gGLManager.mHasNVXMemInfo)
-        {
-            S32 free_memory;
-            glGetIntegerv(GL_GPU_MEMORY_INFO_CURRENT_AVAILABLE_VIDMEM_NVX, &free_memory);
-            LLImageGLThread::sFreeVRAMMegabytes = free_memory / 1024;
-        }
-    };
-
-    
-    // post update to background thread if available, otherwise execute immediately
-    auto queue = LL::WorkQueue::getInstance("LLImageGL");
-    if (sEnabled)
-    {
-        queue->post(func);
-    }
-    else
-    {
-        llassert(queue == nullptr);
-        func();
-    }
-}
-
 void LLImageGL::syncToMainThread(LLGLuint new_tex_name)
 {
     LL_PROFILE_ZONE_SCOPED;
@@ -1874,7 +1880,6 @@ void LLImageGL::destroyGLTexture()
 	{
 		if(mTextureMemory != S32Bytes(0))
 		{
-			sGlobalTextureMemory -= mTextureMemory;
 			mTextureMemory = (S32Bytes)0;
 		}
 		
@@ -2426,13 +2431,9 @@ void LLImageGL::checkActiveThread()
 		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL,  nummips);
 */  
 
-std::atomic<S32> LLImageGLThread::sFreeVRAMMegabytes(4096); //if free vram is unknown, default to 4GB
-
 LLImageGLThread::LLImageGLThread(LLWindow* window)
-    // We want exactly one thread, but a very large capacity: we never want
-    // anyone, especially inner-loop render code, to have to block on post()
-    // because we're full.
-    : ThreadPool("LLImageGL", 1, 1024*1024)
+    // We want exactly one thread.
+    : ThreadPool("LLImageGL", 1)
     , mWindow(window)
 {
     LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
@@ -2455,8 +2456,3 @@ void LLImageGLThread::run()
     mWindow->destroySharedContext(mContext);
 }
 
-S32 LLImageGLThread::getFreeVRAMMegabytes()
-{
-    return sFreeVRAMMegabytes;
-}
-
diff --git a/indra/llrender/llimagegl.h b/indra/llrender/llimagegl.h
index b419c9fab5..b4618fd35c 100644
--- a/indra/llrender/llimagegl.h
+++ b/indra/llrender/llimagegl.h
@@ -52,6 +52,13 @@ class LLImageGL : public LLRefCount
 {
 	friend class LLTexUnit;
 public:
+
+    // Get an estimate of how many bytes have been allocated in vram for textures.
+    // Does not include mipmaps.
+    // NOTE: multiplying this number by two gives a good estimate for total
+    // video memory usage based on testing in lagland against an NVIDIA GPU.
+    static U64 getTextureBytesAllocated();
+
 	// These 2 functions replace glGenTextures() and glDeleteTextures()
 	static void generateTextures(S32 numTextures, U32 *textures);
 	static void deleteTextures(S32 numTextures, const U32 *textures);
@@ -61,7 +68,7 @@ public:
 	static S32 dataFormatBytes(S32 dataformat, S32 width, S32 height);
 	static S32 dataFormatComponents(S32 dataformat);
 
-	BOOL updateBindStats(S32Bytes tex_mem) const ;
+	BOOL updateBindStats() const ;
 	F32 getTimePassedSinceLastBound();
 	void forceUpdateBindStats(void) const;
 
@@ -73,9 +80,6 @@ public:
 	static void restoreGL();
 	static void dirtyTexOptions();
 
-	// Sometimes called externally for textures not using LLImageGL (should go away...)	
-	static S32 updateBoundTexMem(const S32Bytes mem, const S32 ncomponents, S32 category) ;
-	
 	static bool checkSize(S32 width, S32 height);
 
 	//for server side use only.
@@ -165,7 +169,7 @@ public:
 	void updatePickMask(S32 width, S32 height, const U8* data_in);
 	BOOL getMask(const LLVector2 &tc);
 
-	void checkTexSize(bool forced = false) const ;
+    void checkTexSize(bool forced = false) const ;
 	
 	// Sets the addressing mode used to sample the texture 
 	//  (such as wrapping, mirrored wrapping, and clamp)
@@ -265,9 +269,6 @@ public:
 	static F32 sLastFrameTime;
 
 	// Global memory statistics
-	static S32Bytes sGlobalTextureMemory;	// Tracks main memory texmem
-	static S32Bytes sBoundTextureMemory;	// Tracks bound texmem for last completed frame
-	static S32Bytes sCurBoundTextureMemory;		// Tracks bound texmem for current frame
 	static U32 sBindCount;					// Tracks number of texture binds for current frame
 	static U32 sUniqueCount;				// Tracks number of unique texture binds for current frame
 	static BOOL sGlobalUseAnisotropic;
@@ -327,12 +328,6 @@ public:
     // follows gSavedSettings "RenderGLMultiThreaded"
     static bool sEnabled;
     
-    // app should call this function periodically
-    static void updateClass();
-
-    // free video memory in megabytes
-    static std::atomic<S32> sFreeVRAMMegabytes;
-
     LLImageGLThread(LLWindow* window);
 
     // post a function to be executed on the LLImageGL background thread
@@ -344,8 +339,6 @@ public:
 
     void run() override;
 
-    static S32 getFreeVRAMMegabytes();
-
 private:
     LLWindow* mWindow;
     void* mContext = nullptr;
diff --git a/indra/llrender/llrender.cpp b/indra/llrender/llrender.cpp
index 3adb47f493..e5bd19e91c 100644
--- a/indra/llrender/llrender.cpp
+++ b/indra/llrender/llrender.cpp
@@ -224,7 +224,7 @@ bool LLTexUnit::bind(LLTexture* texture, bool for_rendering, bool forceBind)
 					enable(gl_tex->getTarget());
 					mCurrTexture = gl_tex->getTexName();
 					glBindTexture(sGLTextureType[gl_tex->getTarget()], mCurrTexture);
-					if(gl_tex->updateBindStats(gl_tex->mTextureMemory))
+					if(gl_tex->updateBindStats())
 					{
 						texture->setActive() ;
 						texture->updateBindStatsForTester() ;
@@ -303,7 +303,7 @@ bool LLTexUnit::bind(LLImageGL* texture, bool for_rendering, bool forceBind, S32
 		mCurrTexture = texname;
 		glBindTexture(sGLTextureType[texture->getTarget()], mCurrTexture);
 		stop_glerror();
-		texture->updateBindStats(texture->mTextureMemory);		
+        texture->updateBindStats();
 		mHasMipMaps = texture->mHasMipMaps;
 		if (texture->mTexOptionsDirty)
 		{
@@ -342,7 +342,7 @@ bool LLTexUnit::bind(LLCubeMap* cubeMap)
             mCurrTexture = cubeMap->mImages[0]->getTexName();
 			glBindTexture(GL_TEXTURE_CUBE_MAP_ARB, mCurrTexture);
 			mHasMipMaps = cubeMap->mImages[0]->mHasMipMaps;
-			cubeMap->mImages[0]->updateBindStats(cubeMap->mImages[0]->mTextureMemory);
+			cubeMap->mImages[0]->updateBindStats();
 			if (cubeMap->mImages[0]->mTexOptionsDirty)
 			{
 				cubeMap->mImages[0]->mTexOptionsDirty = false;
diff --git a/indra/llwindow/CMakeLists.txt b/indra/llwindow/CMakeLists.txt
index 70eb99c86c..32f0fa14c4 100644
--- a/indra/llwindow/CMakeLists.txt
+++ b/indra/llwindow/CMakeLists.txt
@@ -145,6 +145,8 @@ if (WINDOWS)
   list(APPEND llwindow_LINK_LIBRARIES
        comdlg32     # Common Dialogs for ChooseColor
        ole32
+       dxgi
+       d3d9
        )
 endif (WINDOWS)
 
diff --git a/indra/llwindow/llopenglview-objc.mm b/indra/llwindow/llopenglview-objc.mm
index fd20f2ad15..8d064ec86c 100644
--- a/indra/llwindow/llopenglview-objc.mm
+++ b/indra/llwindow/llopenglview-objc.mm
@@ -141,7 +141,12 @@ attributedStringInfo getSegments(NSAttributedString *str)
     CGLError the_err = CGLQueryRendererInfo (CGDisplayIDToOpenGLDisplayMask(kCGDirectMainDisplay), &info, &num_renderers);
     if(0 == the_err)
     {
-        CGLDescribeRenderer (info, 0, kCGLRPTextureMemoryMegabytes, &vram_megabytes);
+        // The name, uses, and other platform definitions of gGLManager.mVRAM suggest that this is supposed to be total vram in MB,
+        // rather than, say, just the texture memory. The two exceptions are:
+        // 1. LLAppViewer::getViewerInfo() puts the value in a field labeled "TEXTURE_MEMORY"
+        // 2. For years, this present function used kCGLRPTextureMemoryMegabytes
+        // Now we use kCGLRPVideoMemoryMegabytes to bring it in line with everything else (except thatone label).
+        CGLDescribeRenderer (info, 0, kCGLRPVideoMemoryMegabytes, &vram_megabytes);
         CGLDestroyRendererInfo (info);
     }
     else
diff --git a/indra/llwindow/llwindow.h b/indra/llwindow/llwindow.h
index 0edf39f6ef..2c538a60c9 100644
--- a/indra/llwindow/llwindow.h
+++ b/indra/llwindow/llwindow.h
@@ -162,7 +162,10 @@ public:
 	virtual F32	getNativeAspectRatio() = 0;
 	virtual F32 getPixelAspectRatio() = 0;
 	virtual void setNativeAspectRatio(F32 aspect) = 0;
-	
+
+	// query VRAM usage
+	virtual U32 getAvailableVRAMMegabytes() = 0;
+
 	virtual void beforeDialog() {};	// prepare to put up an OS dialog (if special measures are required, such as in fullscreen mode)
 	virtual void afterDialog() {};	// undo whatever was done in beforeDialog()
 
diff --git a/indra/llwindow/llwindowheadless.h b/indra/llwindow/llwindowheadless.h
index 410da79623..2f2c0de5bd 100644
--- a/indra/llwindow/llwindowheadless.h
+++ b/indra/llwindow/llwindowheadless.h
@@ -32,72 +32,79 @@
 class LLWindowHeadless : public LLWindow
 {
 public:
-	/*virtual*/ void show() {};
-	/*virtual*/ void hide() {};
-	/*virtual*/ void close() {};
-	/*virtual*/ BOOL getVisible() {return FALSE;};
-	/*virtual*/ BOOL getMinimized() {return FALSE;};
-	/*virtual*/ BOOL getMaximized() {return FALSE;};
-	/*virtual*/ BOOL maximize() {return FALSE;};
-	/*virtual*/ void minimize() {};
-	/*virtual*/ void restore() {};
-	/*virtual*/ BOOL getFullscreen() {return FALSE;};
-	/*virtual*/ BOOL getPosition(LLCoordScreen *position) {return FALSE;};
-	/*virtual*/ BOOL getSize(LLCoordScreen *size) {return FALSE;};
-	/*virtual*/ BOOL getSize(LLCoordWindow *size) {return FALSE;};
-	/*virtual*/ BOOL setPosition(LLCoordScreen position) {return FALSE;};
-	/*virtual*/ BOOL setSizeImpl(LLCoordScreen size) {return FALSE;};
-	/*virtual*/ BOOL setSizeImpl(LLCoordWindow size) {return FALSE;};
-	/*virtual*/ BOOL switchContext(BOOL fullscreen, const LLCoordScreen &size, BOOL enable_vsync, const LLCoordScreen * const posp = NULL) {return FALSE;};
-    void* createSharedContext()  { return nullptr; }
-    void makeContextCurrent(void*)  {}
-    void destroySharedContext(void*)  {}
-    /*virtual*/ void toggleVSync(bool enable_vsync) { }
-    /*virtual*/ BOOL setCursorPosition(LLCoordWindow position) {return FALSE;};
-    /*virtual*/ BOOL getCursorPosition(LLCoordWindow *position) {return FALSE;};
+	/*virtual*/ void show() override {}
+	/*virtual*/ void hide() override {}
+	/*virtual*/ void close() override {}
+	/*virtual*/ BOOL getVisible() override {return FALSE;}
+	/*virtual*/ BOOL getMinimized() override {return FALSE;}
+	/*virtual*/ BOOL getMaximized() override {return FALSE;}
+	/*virtual*/ BOOL maximize() override {return FALSE;}
+	/*virtual*/ void minimize() override {}
+	/*virtual*/ void restore() override {}
+	// TODO: LLWindow::getFullscreen() is (intentionally?) NOT virtual.
+	// Apparently the coder of LLWindowHeadless didn't realize that. Is it a
+	// mistake to shadow the base-class method with an LLWindowHeadless
+	// override when called on the subclass, yet call the base-class method
+	// when indirecting through a polymorphic pointer or reference?
+	BOOL getFullscreen() {return FALSE;}
+	/*virtual*/ BOOL getPosition(LLCoordScreen *position) override {return FALSE;}
+	/*virtual*/ BOOL getSize(LLCoordScreen *size) override {return FALSE;}
+	/*virtual*/ BOOL getSize(LLCoordWindow *size) override {return FALSE;}
+	/*virtual*/ BOOL setPosition(LLCoordScreen position) override {return FALSE;}
+	/*virtual*/ BOOL setSizeImpl(LLCoordScreen size) override {return FALSE;}
+	/*virtual*/ BOOL setSizeImpl(LLCoordWindow size) override {return FALSE;}
+	/*virtual*/ BOOL switchContext(BOOL fullscreen, const LLCoordScreen &size, BOOL enable_vsync, const LLCoordScreen * const posp = NULL) override {return FALSE;}
+    void* createSharedContext() override  { return nullptr; }
+    void makeContextCurrent(void*) override  {}
+    void destroySharedContext(void*) override  {}
+    /*virtual*/ void toggleVSync(bool enable_vsync) override { }
+    /*virtual*/ BOOL setCursorPosition(LLCoordWindow position) override {return FALSE;}
+    /*virtual*/ BOOL getCursorPosition(LLCoordWindow *position) override {return FALSE;}
 #if LL_WINDOWS
-    /*virtual*/ BOOL getCursorDelta(LLCoordCommon* delta) { return FALSE; }
+    /*virtual*/ BOOL getCursorDelta(LLCoordCommon* delta) override { return FALSE; }
 #endif
-	/*virtual*/ void showCursor() {};
-	/*virtual*/ void hideCursor() {};
-	/*virtual*/ void showCursorFromMouseMove() {};
-	/*virtual*/ void hideCursorUntilMouseMove() {};
-	/*virtual*/ BOOL isCursorHidden() {return FALSE;};
-	/*virtual*/ void updateCursor() {};
-	//virtual ECursorType getCursor() { return mCurrentCursor; };
-	/*virtual*/ void captureMouse() {};
-	/*virtual*/ void releaseMouse() {};
-	/*virtual*/ void setMouseClipping( BOOL b ) {};
-	/*virtual*/ BOOL isClipboardTextAvailable() {return FALSE; };
-	/*virtual*/ BOOL pasteTextFromClipboard(LLWString &dst) {return FALSE; };
-	/*virtual*/ BOOL copyTextToClipboard(const LLWString &src) {return FALSE; };
-	/*virtual*/ void flashIcon(F32 seconds) {};
-	/*virtual*/ F32 getGamma() {return 1.0f; };
-	/*virtual*/ BOOL setGamma(const F32 gamma) {return FALSE; }; // Set the gamma
-	/*virtual*/ void setFSAASamples(const U32 fsaa_samples) { }
-	/*virtual*/ U32 getFSAASamples() { return 0; }
-	/*virtual*/ BOOL restoreGamma() {return FALSE; };	// Restore original gamma table (before updating gamma)
-	//virtual ESwapMethod getSwapMethod() { return mSwapMethod; }
-	/*virtual*/ void gatherInput() {};
-	/*virtual*/ void delayInputProcessing() {};
-	/*virtual*/ void swapBuffers();
+	/*virtual*/ void showCursor() override {}
+	/*virtual*/ void hideCursor() override {}
+	/*virtual*/ void showCursorFromMouseMove() override {}
+	/*virtual*/ void hideCursorUntilMouseMove() override {}
+	/*virtual*/ BOOL isCursorHidden() override {return FALSE;}
+	/*virtual*/ void updateCursor() override {}
+	//virtual ECursorType getCursor() override { return mCurrentCursor; }
+	/*virtual*/ void captureMouse() override {}
+	/*virtual*/ void releaseMouse() override {}
+	/*virtual*/ void setMouseClipping( BOOL b ) override {}
+	/*virtual*/ BOOL isClipboardTextAvailable() override {return FALSE; }
+	/*virtual*/ BOOL pasteTextFromClipboard(LLWString &dst) override {return FALSE; }
+	/*virtual*/ BOOL copyTextToClipboard(const LLWString &src) override {return FALSE; }
+	/*virtual*/ void flashIcon(F32 seconds) override {}
+	/*virtual*/ F32 getGamma() override {return 1.0f; }
+	/*virtual*/ BOOL setGamma(const F32 gamma) override {return FALSE; } // Set the gamma
+	/*virtual*/ void setFSAASamples(const U32 fsaa_samples) override { }
+	/*virtual*/ U32 getFSAASamples() override { return 0; }
+	/*virtual*/ BOOL restoreGamma() override {return FALSE; }	// Restore original gamma table (before updating gamma)
+	//virtual ESwapMethod getSwapMethod() override { return mSwapMethod; }
+	/*virtual*/ void gatherInput() override {}
+	/*virtual*/ void delayInputProcessing() override {}
+	/*virtual*/ void swapBuffers() override;
 
 	
     // handy coordinate space conversion routines
-	/*virtual*/ BOOL convertCoords(LLCoordScreen from, LLCoordWindow *to) { return FALSE; };
-	/*virtual*/ BOOL convertCoords(LLCoordWindow from, LLCoordScreen *to) { return FALSE; };
-	/*virtual*/ BOOL convertCoords(LLCoordWindow from, LLCoordGL *to) { return FALSE; };
-	/*virtual*/ BOOL convertCoords(LLCoordGL from, LLCoordWindow *to) { return FALSE; };
-	/*virtual*/ BOOL convertCoords(LLCoordScreen from, LLCoordGL *to) { return FALSE; };
-	/*virtual*/ BOOL convertCoords(LLCoordGL from, LLCoordScreen *to) { return FALSE; };
+	/*virtual*/ BOOL convertCoords(LLCoordScreen from, LLCoordWindow *to) override { return FALSE; }
+	/*virtual*/ BOOL convertCoords(LLCoordWindow from, LLCoordScreen *to) override { return FALSE; }
+	/*virtual*/ BOOL convertCoords(LLCoordWindow from, LLCoordGL *to) override { return FALSE; }
+	/*virtual*/ BOOL convertCoords(LLCoordGL from, LLCoordWindow *to) override { return FALSE; }
+	/*virtual*/ BOOL convertCoords(LLCoordScreen from, LLCoordGL *to) override { return FALSE; }
+	/*virtual*/ BOOL convertCoords(LLCoordGL from, LLCoordScreen *to) override { return FALSE; }
 
-	/*virtual*/ LLWindowResolution* getSupportedResolutions(S32 &num_resolutions) { return NULL; };
-	/*virtual*/ F32	getNativeAspectRatio() { return 1.0f; };
-	/*virtual*/ F32 getPixelAspectRatio() { return 1.0f; };
-	/*virtual*/ void setNativeAspectRatio(F32 ratio) {}
+	/*virtual*/ LLWindowResolution* getSupportedResolutions(S32 &num_resolutions) override { return NULL; }
+	/*virtual*/ F32	getNativeAspectRatio() override { return 1.0f; }
+	/*virtual*/ F32 getPixelAspectRatio() override { return 1.0f; }
+	/*virtual*/ void setNativeAspectRatio(F32 ratio) override {}
 
-	/*virtual*/ void *getPlatformWindow() { return 0; };
-	/*virtual*/ void bringToFront() {};
+    U32 getAvailableVRAMMegabytes() override { return 4096; }
+
+	/*virtual*/ void *getPlatformWindow() override { return 0; }
+	/*virtual*/ void bringToFront() override {}
 	
 	LLWindowHeadless(LLWindowCallbacks* callbacks,
 		const std::string& title, const std::string& name,
@@ -113,12 +120,12 @@ private:
 class LLSplashScreenHeadless : public LLSplashScreen
 {
 public:
-	LLSplashScreenHeadless() {};
-	virtual ~LLSplashScreenHeadless() {};
+	LLSplashScreenHeadless() {}
+	virtual ~LLSplashScreenHeadless() {}
 
-	/*virtual*/ void showImpl() {};
-	/*virtual*/ void updateImpl(const std::string& mesg) {};
-	/*virtual*/ void hideImpl() {};
+	/*virtual*/ void showImpl() override {}
+	/*virtual*/ void updateImpl(const std::string& mesg) override {}
+	/*virtual*/ void hideImpl() override {}
 
 };
 
diff --git a/indra/llwindow/llwindowmacosx.cpp b/indra/llwindow/llwindowmacosx.cpp
index bc4f07941b..4bcb9b3aef 100644
--- a/indra/llwindow/llwindowmacosx.cpp
+++ b/indra/llwindow/llwindowmacosx.cpp
@@ -1222,6 +1222,16 @@ F32 LLWindowMacOSX::getPixelAspectRatio()
 	return 1.f;
 }
 
+U32 LLWindowMacOSX::getAvailableVRAMMegabytes() {
+    // MTL (and MoltenVK) has some additional gpu data, such as recommendedMaxWorkingSetSize and currentAllocatedSize.
+    // But these are not available for OpenGL and/or our current mimimum OS version.
+    // So we will estimate.
+    static const U32 mb = 1024*1024;
+    // We're asked for total available gpu memory, but we only have allocation info on texture usage. So estimate by doubling that.
+    static const U32 total_factor = 2; // estimated total/textures
+    return gGLManager.mVRAM - (LLImageGL::getTextureBytesAllocated() * total_factor/mb);
+}
+
 //static SInt32 oldWindowLevel;
 
 // MBW -- XXX -- There's got to be a better way than this.  Find it, please...
diff --git a/indra/llwindow/llwindowmacosx.h b/indra/llwindow/llwindowmacosx.h
index b0f339e1db..0f316f1ddf 100644
--- a/indra/llwindow/llwindowmacosx.h
+++ b/indra/llwindow/llwindowmacosx.h
@@ -100,6 +100,9 @@ public:
 	F32 getPixelAspectRatio() override;
 	void setNativeAspectRatio(F32 ratio) override { mOverrideAspectRatio = ratio; }
 
+	// query VRAM usage
+    /*virtual*/ U32 getAvailableVRAMMegabytes() override;
+
 	void beforeDialog() override;
 	void afterDialog() override;
 
diff --git a/indra/llwindow/llwindowwin32.cpp b/indra/llwindow/llwindowwin32.cpp
index 1f23040260..553507bc0c 100644
--- a/indra/llwindow/llwindowwin32.cpp
+++ b/indra/llwindow/llwindowwin32.cpp
@@ -47,6 +47,9 @@
 #include "llglslshader.h"
 #include "llthreadsafequeue.h"
 #include "stringize.h"
+#include "llframetimer.h"
+#include "commoncontrol.h" // TODO: Remove after testing
+#include "llsd.h" // TODO: Remove after testing
 
 // System includes
 #include <commdlg.h>
@@ -61,6 +64,9 @@
 #include <sstream>
 #include <utility>                  // std::pair
 
+#include <d3d9.h>
+#include <dxgi1_4.h>
+
 // Require DirectInput version 8
 #define DIRECTINPUT_VERSION 0x0800
 
@@ -347,6 +353,20 @@ struct LLWindowWin32::LLWindowWin32Thread : public LL::ThreadPool
 
     void run() override;
 
+    // initialzie DXGI adapter (for querying available VRAM)
+    void initDX();
+    
+    // initialize D3D (if DXGI cannot be used)
+    void initD3D();
+
+    // call periodically to update available VRAM
+    void updateVRAMUsage();
+
+    U32 getAvailableVRAMMegabytes()
+    {
+        return mAvailableVRAM;
+    }
+
     /// called by main thread to post work to this window thread
     template <typename CALLABLE>
     void post(CALLABLE&& func)
@@ -395,6 +415,15 @@ struct LLWindowWin32::LLWindowWin32Thread : public LL::ThreadPool
     void gatherInput();
     HWND mWindowHandle = NULL;
     HDC mhDC = 0;
+
+    // best guess at available video memory in MB
+    std::atomic<U32> mAvailableVRAM;
+
+    bool mTryUseDXGIAdapter; // TODO: Remove after testing
+    IDXGIAdapter3* mDXGIAdapter = nullptr;
+    bool mTryUseD3DDevice; // TODO: Remove after testing
+    LPDIRECT3D9 mD3D = nullptr;
+    LPDIRECT3DDEVICE9 mD3DDevice = nullptr;
 };
 
 
@@ -4531,12 +4560,24 @@ std::vector<std::string> LLWindowWin32::getDynamicFallbackFontList()
 	return std::vector<std::string>();
 }
 
+U32 LLWindowWin32::getAvailableVRAMMegabytes()
+{
+    return mWindowThread ? mWindowThread->getAvailableVRAMMegabytes() : 0;
+}
 
 #endif // LL_WINDOWS
 
 inline LLWindowWin32::LLWindowWin32Thread::LLWindowWin32Thread()
     : ThreadPool("Window Thread", 1, MAX_QUEUE_SIZE)
 {
+    const LLSD skipDXGI{ LL::CommonControl::get("Global", "DisablePrimaryGraphicsMemoryAccounting") }; // TODO: Remove after testing
+    LL_WARNS() << "DisablePrimaryGraphicsMemoryAccounting: " << skipDXGI << ", as boolean: " << skipDXGI.asBoolean() << LL_ENDL;
+    mTryUseDXGIAdapter = !skipDXGI.asBoolean();
+    LL_WARNS() << "mTryUseDXGIAdapter: " << mTryUseDXGIAdapter << LL_ENDL;
+    const LLSD skipD3D{ LL::CommonControl::get("Global", "DisableSecondaryGraphicsMemoryAccounting") }; // TODO: Remove after testing
+    LL_WARNS() << "DisableSecondaryGraphicsMemoryAccounting: " << skipD3D << ", as boolean: " << skipD3D.asBoolean() << LL_ENDL;
+    mTryUseD3DDevice = !skipD3D.asBoolean();
+    LL_WARNS() << "mTryUseD3DDevice: " << mTryUseD3DDevice << LL_ENDL;
     ThreadPool::start();
 }
 
@@ -4586,17 +4627,216 @@ private:
     std::string mPrev;
 };
 
+// Print hardware debug info about available graphics adapters in ordinal order
+void debugEnumerateGraphicsAdapters()
+{
+    LL_INFOS("Window") << "Enumerating graphics adapters..." << LL_ENDL;
+
+    IDXGIFactory1* factory;
+    HRESULT res = CreateDXGIFactory1(__uuidof(IDXGIFactory1), (void**)&factory);
+    if (FAILED(res) || !factory)
+    {
+        LL_WARNS() << "CreateDXGIFactory1 failed: 0x" << std::hex << res << LL_ENDL;
+    }
+    else
+    {
+        UINT graphics_adapter_index = 0;
+        IDXGIAdapter3* dxgi_adapter;
+        while (true)
+        {
+            res = factory->EnumAdapters(graphics_adapter_index, reinterpret_cast<IDXGIAdapter**>(&dxgi_adapter));
+            if (FAILED(res))
+            {
+                if (graphics_adapter_index == 0)
+                {
+                    LL_WARNS() << "EnumAdapters failed: 0x" << std::hex << res << LL_ENDL;
+                }
+                else
+                {
+                    LL_INFOS("Window") << "Done enumerating graphics adapters" << LL_ENDL;
+                }
+            }
+            else
+            {
+                DXGI_ADAPTER_DESC desc;
+                dxgi_adapter->GetDesc(&desc);
+                std::wstring description_w((wchar_t*)desc.Description);
+                std::string description(description_w.begin(), description_w.end());
+                LL_INFOS("Window") << "Graphics adapter index: " << graphics_adapter_index << ", "
+                    << "Description: " << description << ", "
+                    << "DeviceId: " << desc.DeviceId << ", "
+                    << "SubSysId: " << desc.SubSysId << ", "
+                    << "AdapterLuid: " << desc.AdapterLuid.HighPart << "_" << desc.AdapterLuid.LowPart << ", "
+                    << "DedicatedVideoMemory: " << desc.DedicatedVideoMemory / 1024 / 1024 << ", "
+                    << "DedicatedSystemMemory: " << desc.DedicatedSystemMemory / 1024 / 1024 << ", "
+                    << "SharedSystemMemory: " << desc.SharedSystemMemory / 1024 / 1024 << LL_ENDL;
+            }
+
+            if (dxgi_adapter)
+            {
+                dxgi_adapter->Release();
+                dxgi_adapter = NULL;
+            }
+            else
+            {
+                break;
+            }
+
+            graphics_adapter_index++;
+        }
+    }
+
+    if (factory)
+    {
+        factory->Release();
+    }
+}
+
+void LLWindowWin32::LLWindowWin32Thread::initDX()
+{
+    if (mDXGIAdapter == NULL && mTryUseDXGIAdapter)
+    {
+        debugEnumerateGraphicsAdapters();
+
+        IDXGIFactory4* pFactory = nullptr;
+
+        HRESULT res = CreateDXGIFactory1(__uuidof(IDXGIFactory4), (void**)&pFactory);
+
+        if (FAILED(res))
+        {
+            LL_WARNS() << "CreateDXGIFactory1 failed: 0x" << std::hex << res << LL_ENDL;
+        }
+        else
+        {
+            res = pFactory->EnumAdapters(0, reinterpret_cast<IDXGIAdapter**>(&mDXGIAdapter));
+            if (FAILED(res))
+            {
+                LL_WARNS() << "EnumAdapters failed: 0x" << std::hex << res << LL_ENDL;
+            }
+            else
+            {
+                LL_INFOS() << "EnumAdapters success" << LL_ENDL;
+            }
+        }
+
+        if (pFactory)
+        {
+            pFactory->Release();
+        }
+    }
+}
+
+void LLWindowWin32::LLWindowWin32Thread::initD3D()
+{
+    if (mDXGIAdapter == NULL && mD3DDevice == NULL && mTryUseD3DDevice && mWindowHandle != 0)
+    {
+        mD3D = Direct3DCreate9(D3D_SDK_VERSION);
+        
+        D3DPRESENT_PARAMETERS d3dpp;
+
+        ZeroMemory(&d3dpp, sizeof(d3dpp));
+        d3dpp.Windowed = TRUE;
+        d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
+
+        HRESULT res = mD3D->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, mWindowHandle, D3DCREATE_SOFTWARE_VERTEXPROCESSING, &d3dpp, &mD3DDevice);
+        
+        if (FAILED(res))
+        {
+            LL_WARNS() << "(fallback) CreateDevice failed: 0x" << std::hex << res << LL_ENDL;
+        }
+        else
+        {
+            LL_INFOS() << "(fallback) CreateDevice success" << LL_ENDL;
+        }
+    }
+}
+
+void LLWindowWin32::LLWindowWin32Thread::updateVRAMUsage()
+{
+    LL_PROFILE_ZONE_SCOPED;
+    if (mDXGIAdapter != nullptr)
+    {
+        // NOTE: what lies below is hand wavy math based on compatibility testing and observation against a variety of hardware
+        //  It doesn't make sense, but please don't refactor it to make sense. -- davep
+
+        DXGI_QUERY_VIDEO_MEMORY_INFO info;
+        mDXGIAdapter->QueryVideoMemoryInfo(0, DXGI_MEMORY_SEGMENT_GROUP_LOCAL, &info);
+
+#if 0 // debug 0 budget and 0 CU
+        info.Budget = 0;
+        info.CurrentUsage = 0;
+#endif
+
+        U32 budget_mb = info.Budget / 1024 / 1024;
+        U32 afr_mb = info.AvailableForReservation / 1024 / 1024;
+        // correct for systems that misreport budget
+        if (budget_mb == 0)
+        { 
+            // fall back to available for reservation clamped between 512MB and 2GB
+            budget_mb = llclamp(afr_mb, (U32) 512, (U32) 2048);
+        }
+
+        U32 cu_mb = info.CurrentUsage / 1024 / 1024;
+
+        // get an estimated usage based on texture bytes allocated
+        U32 eu_mb = LLImageGL::getTextureBytesAllocated() * 2 / 1024 / 1024;
+
+        if (cu_mb == 0)
+        { // current usage is sometimes unreliable on Intel GPUs, fall back to estimated usage
+            cu_mb = llmax((U32)1, eu_mb);
+        }
+        F32 eu_error = (F32)((S32)eu_mb - (S32)cu_mb) / (F32)cu_mb;
+
+        U32 target_mb = info.Budget / 1024 / 1024;
+
+        if (target_mb > 4096)  // if 4GB are installed, try to leave 2GB free 
+        {
+            target_mb -= 2048;
+        }
+        else // if less than 4GB are installed, try not to use more than half of it
+        {
+            target_mb /= 2;
+        }
+
+        mAvailableVRAM = cu_mb < target_mb ? target_mb - cu_mb : 0;
+
+        LL_INFOS("Window") << "\nLocal\nAFR: " << info.AvailableForReservation / 1024 / 1024
+            << "\nBudget: " << info.Budget / 1024 / 1024
+            << "\nCR: " << info.CurrentReservation / 1024 / 1024
+            << "\nCU: " << info.CurrentUsage / 1024 / 1024
+            << "\nEU: " << eu_mb << llformat(" (%.2f)", eu_error)
+            << "\nTU: " << target_mb
+            << "\nAM: " << mAvailableVRAM << LL_ENDL;
+
+        /*mDXGIAdapter->QueryVideoMemoryInfo(0, DXGI_MEMORY_SEGMENT_GROUP_NON_LOCAL, &info);
+        LL_INFOS("Window") << "\nNon-Local\nAFR: " << info.AvailableForReservation / 1024 / 1024
+            << "\nBudget: " << info.Budget / 1024 / 1024
+            << "\nCR: " << info.CurrentReservation / 1024 / 1024
+            << "\nCU: " << info.CurrentUsage / 1024 / 1024 << LL_ENDL;*/
+    }
+    else if (mD3DDevice != NULL)
+    { // fallback to D3D9
+        mAvailableVRAM = mD3DDevice->GetAvailableTextureMem() / 1024 / 1024;
+    }
+}
+
 void LLWindowWin32::LLWindowWin32Thread::run()
 {
     sWindowThreadId = std::this_thread::get_id();
     LogChange logger("Window");
 
+    initDX();
+
     while (! getQueue().done())
     {
         LL_PROFILE_ZONE_SCOPED_CATEGORY_WIN32;
 
         if (mWindowHandle != 0)
         {
+            // lazily call initD3D inside this loop to catch when mWindowHandle has been set
+            // *TODO: Shutdown if this fails when mWindowHandle exists
+            initD3D();
+
             MSG msg;
             BOOL status;
             if (mhDC == 0)
@@ -4629,6 +4869,13 @@ void LLWindowWin32::LLWindowWin32Thread::run()
             getQueue().runPending();
         }
         
+        // update available vram once every 3 seconds
+        static LLFrameTimer vramTimer;
+        if (vramTimer.getElapsedTimeF32() > 3.f)
+        {
+            updateVRAMUsage();
+            vramTimer.reset();
+        }
 #if 0
         {
             LL_PROFILE_ZONE_NAMED_CATEGORY_WIN32("w32t - Sleep");
@@ -4637,6 +4884,26 @@ void LLWindowWin32::LLWindowWin32Thread::run()
         }
 #endif
     }
+
+    //clean up DXGI/D3D resources
+    if (mDXGIAdapter)
+    {
+        mDXGIAdapter->Release();
+        mDXGIAdapter = nullptr;
+    }
+
+    if (mD3DDevice)
+    {
+        mD3DDevice->Release();
+        mD3DDevice = nullptr;
+    }
+
+    if (mD3D)
+    {
+        mD3D->Release();
+        mD3D = nullptr;
+    }
+
 }
 
 void LLWindowWin32::post(const std::function<void()>& func)
diff --git a/indra/llwindow/llwindowwin32.h b/indra/llwindow/llwindowwin32.h
index b391acc12d..bd53b3e92a 100644
--- a/indra/llwindow/llwindowwin32.h
+++ b/indra/llwindow/llwindowwin32.h
@@ -108,7 +108,9 @@ public:
 	/*virtual*/ F32 getPixelAspectRatio();
 	/*virtual*/ void setNativeAspectRatio(F32 ratio) { mOverrideAspectRatio = ratio; }
 
-	/*virtual*/	BOOL dialogColorPicker(F32 *r, F32 *g, F32 *b );
+    U32 getAvailableVRAMMegabytes() override;
+	
+    /*virtual*/	BOOL dialogColorPicker(F32 *r, F32 *g, F32 *b );
 
 	/*virtual*/ void *getPlatformWindow();
 	/*virtual*/ void bringToFront();
diff --git a/indra/newview/CMakeLists.txt b/indra/newview/CMakeLists.txt
index 950697a72a..213b34b4a6 100644
--- a/indra/newview/CMakeLists.txt
+++ b/indra/newview/CMakeLists.txt
@@ -321,7 +321,6 @@ set(viewer_SOURCE_FILES
     llfloatertelehub.cpp
     llfloatertestinspectors.cpp
     llfloatertestlistview.cpp
-    llfloatertexturefetchdebugger.cpp
     llfloatertools.cpp
     llfloatertopobjects.cpp
     llfloatertos.cpp
@@ -967,7 +966,6 @@ set(viewer_HEADER_FILES
     llfloatertelehub.h
     llfloatertestinspectors.h
     llfloatertestlistview.h
-    llfloatertexturefetchdebugger.h
     llfloatertools.h
     llfloatertopobjects.h
     llfloatertos.h
@@ -2519,6 +2517,19 @@ if (LL_TESTS)
     "${test_libs}"
     )
 
+  set(llviewercontrollistener_test_sources
+    llviewercontrollistener.cpp
+    ../llxml/llcontrol.cpp
+    ../llxml/llxmltree.cpp
+    ../llxml/llxmlparser.cpp
+    ../llcommon/commoncontrol.cpp
+    )
+
+  LL_ADD_INTEGRATION_TEST(llviewercontrollistener
+    "${llviewercontrollistener_test_sources}"
+    "${test_libs}"
+    )
+
   LL_ADD_INTEGRATION_TEST(llviewernetwork
      llviewernetwork.cpp
     "${test_libs}"
diff --git a/indra/newview/app_settings/settings.xml b/indra/newview/app_settings/settings.xml
index 0d1870903b..cd33690075 100644
--- a/indra/newview/app_settings/settings.xml
+++ b/indra/newview/app_settings/settings.xml
@@ -3398,6 +3398,29 @@
       <key>Value</key>
       <integer>0</integer>
     </map>
+    <!-- TODO: Remove settings keys DisablePrimaryGraphicsMemoryAccounting and DisableSecondaryGraphicsMemoryAccounting after testing, and code that references them -->
+    <key>DisablePrimaryGraphicsMemoryAccounting</key>
+    <map>
+      <key>Comment</key>
+      <string>Disable the first method used to detect GPU memory use</string>
+      <key>Persist</key>
+      <integer>1</integer>
+      <key>Type</key>
+      <string>Boolean</string>
+      <key>Value</key>
+      <integer>0</integer>
+    </map>
+    <key>DisableSecondaryGraphicsMemoryAccounting</key>
+    <map>
+      <key>Comment</key>
+      <string>Disable the second method used to detect GPU memory use, used as a fallback when the first method fails</string>
+      <key>Persist</key>
+      <integer>1</integer>
+      <key>Type</key>
+      <string>Boolean</string>
+      <key>Value</key>
+      <integer>0</integer>
+    </map>
     <key>DisableTextHyperlinkActions</key>
     <map>
       <key>Comment</key>
@@ -3924,7 +3947,7 @@
         <key>Type</key>
         <string>F32</string>
         <key>Value</key>
-        <real>0.1</real>
+        <real>1.0</real>
     </map>
     <key>QueueInventoryFetchTimeout</key>
     <map>
@@ -10458,17 +10481,6 @@
       <key>Value</key>
       <real>12.0</real>
     </map>
-    <key>RenderTextureMemoryMultiple</key>
-    <map>
-      <key>Comment</key>
-      <string>Multiple of texture memory value to use (should fit: 0 &lt; value &lt;= 1.0)</string>
-      <key>Persist</key>
-      <integer>1</integer>
-      <key>Type</key>
-      <string>F32</string>
-      <key>Value</key>
-      <real>1.0</real>
-    </map>
     <key>RenderTrackerBeacon</key>
     <map>
       <key>Comment</key>
@@ -12548,17 +12560,6 @@
       <key>Value</key>
       <real>20.0</real>
     </map>
-    <key>TexelPixelRatio</key>
-    <map>
-      <key>Comment</key>
-      <string>texel pixel ratio = texel / pixel</string>
-      <key>Persist</key>
-      <integer>1</integer>
-      <key>Type</key>
-      <string>F32</string>
-      <key>Value</key>
-      <real>1.0</real>
-    </map>
     <key>TextureCameraMotionThreshold</key>
     <map>
       <key>Comment</key>
@@ -12658,17 +12659,6 @@
       <key>Value</key>
       <integer>0</integer>
     </map>
-    <key>TextureFetchDebuggerEnabled</key>
-    <map>
-      <key>Comment</key>
-      <string>Enable the texture fetching debugger if set</string>
-      <key>Persist</key>
-      <integer>1</integer>
-      <key>Type</key>
-      <string>Boolean</string>
-      <key>Value</key>
-      <integer>0</integer>
-    </map>
     <key>TextureFetchMinTimeToLog</key>
     <map>
       <key>Comment</key>
@@ -12691,21 +12681,10 @@
     <key>Value</key>
     <real>0.0</real>
   </map>
-    <key>TextureFetchSource</key>
+    <key>TextureFetchUpdateMinCount</key>
     <map>
       <key>Comment</key>
-      <string>Debug use: Source to fetch textures</string>
-      <key>Persist</key>
-      <integer>1</integer>
-      <key>Type</key>
-      <string>S32</string>
-      <key>Value</key>
-      <integer>0</integer>
-    </map>
-    <key>TextureFetchUpdateHighPriority</key>
-    <map>
-      <key>Comment</key>
-      <string>Number of high priority textures to update per frame</string>
+      <string>Minimum number of textures to update per frame</string>
       <key>Persist</key>
       <integer>1</integer>
       <key>Type</key>
@@ -12713,91 +12692,14 @@
       <key>Value</key>
       <integer>32</integer>
     </map>
-    <key>TextureFetchUpdateMaxMediumPriority</key>
-    <map>
-      <key>Comment</key>
-      <string>Maximum number of medium priority textures to update per frame</string>
-      <key>Persist</key>
-      <integer>1</integer>
-      <key>Type</key>
-      <string>S32</string>
-      <key>Value</key>
-      <integer>256</integer>
-    </map>
-    <key>TextureFetchUpdateMinMediumPriority</key>
-    <map>
-      <key>Comment</key>
-      <string>Minimum number of medium priority textures to update per frame</string>
-      <key>Persist</key>
-      <integer>1</integer>
-      <key>Type</key>
-      <string>S32</string>
-      <key>Value</key>
-      <integer>32</integer>
-    </map>
-    <key>TextureFetchUpdatePriorityThreshold</key>
-    <map>
-      <key>Comment</key>
-      <string>Threshold under which textures will be considered too low priority and skipped for update</string>
-      <key>Persist</key>
-      <integer>1</integer>
-      <key>Type</key>
-      <string>F32</string>
-      <key>Value</key>
-      <real>0.0</real>
-    </map>
-    <key>TextureFetchUpdateSkipLowPriority</key>
-    <map>
-      <key>Comment</key>
-      <string>Flag indicating if we want to skip textures with too low of a priority</string>
-      <key>Persist</key>
-      <integer>1</integer>
-      <key>Type</key>
-      <string>Boolean</string>
-      <key>Value</key>
-      <integer>0</integer>
-    </map>
-    <key>TextureFetchUpdatePriorities</key>
-    <map>
-      <key>Comment</key>
-      <string>Number of priority texture to update per frame</string>
-      <key>Persist</key>
-      <integer>1</integer>
-      <key>Type</key>
-      <string>S32</string>
-      <key>Value</key>
-      <integer>32</integer>
-    </map>
-    <key>TextureListFetchingThreshold</key>
-    <map>
-      <key>Comment</key>
-      <string>If the ratio between fetched and all textures in the list is greater than this threshold, which we assume that almost all textures are fetched</string>
-      <key>Persist</key>
-      <integer>1</integer>
-      <key>Type</key>
-      <string>F32</string>
-      <key>Value</key>
-      <real>0.97</real>
-    </map>
     <key>TextureLoadFullRes</key>
     <map>
       <key>Comment</key>
       <string>If TRUE, always load textures at full resolution (discard = 0)</string>
       <key>Persist</key>
-      <integer>0</integer>
-      <key>Type</key>
-      <string>Boolean</string>
-      <key>Value</key>
-      <integer>0</integer>
-    </map>
-    <key>TextureMemory</key>
-    <map>
-      <key>Comment</key>
-      <string>Amount of memory to use for textures in MB (0 = autodetect)</string>
-      <key>Persist</key>
       <integer>1</integer>
       <key>Type</key>
-      <string>S32</string>
+      <string>Boolean</string>
       <key>Value</key>
       <integer>0</integer>
     </map>
@@ -12867,7 +12769,9 @@
       <key>Value</key>
       <map>
         <key>General</key>
-        <integer>4</integer>
+        <integer>1</integer>
+        <key>ImageDecode</key>
+        <integer>9</integer>
       </map>
     </map>
     <key>ThrottleBandwidthKBPS</key>
diff --git a/indra/newview/featuretable.txt b/indra/newview/featuretable.txt
index 3269158903..6b4ab1be17 100644
--- a/indra/newview/featuretable.txt
+++ b/indra/newview/featuretable.txt
@@ -60,7 +60,6 @@ WindLightUseAtmosShaders	1	1
 WLSkyDetail					1	128
 Disregard128DefaultDrawDistance	1	1
 Disregard96DefaultDrawDistance	1	1
-RenderTextureMemoryMultiple		1	1.0
 RenderCompressTextures		1	1
 RenderShaderLightingMaxLevel	1	3
 RenderPBR                   1   1
diff --git a/indra/newview/featuretable_mac.txt b/indra/newview/featuretable_mac.txt
index 7bad9b56f1..311b669d7f 100644
--- a/indra/newview/featuretable_mac.txt
+++ b/indra/newview/featuretable_mac.txt
@@ -60,7 +60,6 @@ WindLightUseAtmosShaders	1	1
 WLSkyDetail					1	128
 Disregard128DefaultDrawDistance	1	1
 Disregard96DefaultDrawDistance	1	1
-RenderTextureMemoryMultiple		1	1.0
 RenderCompressTextures		1	1
 RenderShaderLightingMaxLevel	1	3
 RenderDeferred				1	1
diff --git a/indra/newview/llappviewer.cpp b/indra/newview/llappviewer.cpp
index 225a14dee0..0e2828332e 100644
--- a/indra/newview/llappviewer.cpp
+++ b/indra/newview/llappviewer.cpp
@@ -103,7 +103,6 @@
 #include "lldiskcache.h"
 #include "llvopartgroup.h"
 #include "llweb.h"
-#include "llfloatertexturefetchdebugger.h"
 #include "llspellcheck.h"
 #include "llscenemonitor.h"
 #include "llavatarrenderinfoaccountant.h"
@@ -1551,7 +1550,6 @@ bool LLAppViewer::doFrame()
 			{
 				S32 non_interactive_ms_sleep_time = 100;
 				LLAppViewer::getTextureCache()->pause();
-				LLAppViewer::getImageDecodeThread()->pause();
 				ms_sleep(non_interactive_ms_sleep_time);
 			}
 
@@ -1571,7 +1569,6 @@ bool LLAppViewer::doFrame()
 					ms_sleep(milliseconds_to_sleep);
 					// also pause worker threads during this wait period
 					LLAppViewer::getTextureCache()->pause();
-					LLAppViewer::getImageDecodeThread()->pause();
 				}
 			}
 
@@ -1620,7 +1617,6 @@ bool LLAppViewer::doFrame()
 			{
 				LL_PROFILE_ZONE_NAMED_CATEGORY_APP( "df getTextureCache" )
 				LLAppViewer::getTextureCache()->pause();
-				LLAppViewer::getImageDecodeThread()->pause();
 				LLAppViewer::getTextureFetch()->pause();
 			}
 			if(!total_io_pending) //pause file threads if nothing to process.
@@ -1629,21 +1625,9 @@ bool LLAppViewer::doFrame()
 				LLLFSThread::sLocal->pause();
 			}
 
-			//texture fetching debugger
-			if(LLTextureFetchDebugger::isEnabled())
-			{
-				LL_PROFILE_ZONE_NAMED_CATEGORY_APP( "df tex_fetch_debugger_instance" )
-				LLFloaterTextureFetchDebugger* tex_fetch_debugger_instance =
-					LLFloaterReg::findTypedInstance<LLFloaterTextureFetchDebugger>("tex_fetch_debugger");
-				if(tex_fetch_debugger_instance)
-				{
-					tex_fetch_debugger_instance->idle() ;
-				}
-			}
-
 			{
 				LL_PROFILE_ZONE_NAMED_CATEGORY_APP( "df resumeMainloopTimeout" )
-			resumeMainloopTimeout();
+			    resumeMainloopTimeout();
 			}
 			pingMainloopTimeout("Main:End");
 		}
@@ -1695,16 +1679,20 @@ S32 LLAppViewer::updateTextureThreads(F32 max_time)
 
 void LLAppViewer::flushLFSIO()
 {
-	while (1)
-	{
-		S32 pending = LLLFSThread::updateClass(0);
-		if (!pending)
-		{
-			break;
-		}
-		LL_INFOS() << "Waiting for pending IO to finish: " << pending << LL_ENDL;
-		ms_sleep(100);
-	}
+    S32 pending = LLLFSThread::updateClass(0);
+    if (pending > 0)
+    {
+        LL_INFOS() << "Waiting for pending IO to finish: " << pending << LL_ENDL;
+        while (1)
+        {
+            pending = LLLFSThread::updateClass(0);
+            if (!pending)
+            {
+                break;
+            }
+            ms_sleep(100);
+        }
+    }
 }
 
 bool LLAppViewer::cleanup()
@@ -1861,8 +1849,6 @@ bool LLAppViewer::cleanup()
 
 	LL_INFOS() << "Cache files removed" << LL_ENDL;
 
-	// Wait for any pending LFS IO
-	flushLFSIO();
 	LL_INFOS() << "Shutting down Views" << LL_ENDL;
 
 	// Destroy the UI
@@ -2062,13 +2048,13 @@ bool LLAppViewer::cleanup()
 	sTextureCache->shutdown();
 	sImageDecodeThread->shutdown();
 	sPurgeDiskCacheThread->shutdown();
-    if (mGeneralThreadPool)
-    {
-        mGeneralThreadPool->close();
-    }
+	if (mGeneralThreadPool)
+	{
+		mGeneralThreadPool->close();
+	}
 
 	sTextureFetch->shutDownTextureCacheThread() ;
-	sTextureFetch->shutDownImageDecodeThread() ;
+    LLLFSThread::sLocal->shutdown();
 
 	LL_INFOS() << "Shutting down message system" << LL_ENDL;
 	end_messaging_system();
@@ -2185,14 +2171,7 @@ void LLAppViewer::initGeneralThread()
         return;
     }
 
-    LLSD poolSizes{ gSavedSettings.getLLSD("ThreadPoolSizes") };
-    LLSD sizeSpec{ poolSizes["General"] };
-    LLSD::Integer poolSize{ sizeSpec.isInteger() ? sizeSpec.asInteger() : 3 };
-    LL_DEBUGS("ThreadPool") << "Instantiating General pool with "
-        << poolSize << " threads" << LL_ENDL;
-    // We don't want anyone, especially the main thread, to have to block
-    // due to this ThreadPool being full.
-    mGeneralThreadPool = new LL::ThreadPool("General", poolSize, 1024 * 1024);
+    mGeneralThreadPool = new LL::ThreadPool("General", 3);
     mGeneralThreadPool->start();
 }
 
@@ -2202,13 +2181,12 @@ bool LLAppViewer::initThreads()
 
 	LLImage::initClass(gSavedSettings.getBOOL("TextureNewByteRange"),gSavedSettings.getS32("TextureReverseByteRange"));
 
-	LLLFSThread::initClass(enable_threads && false);
+	LLLFSThread::initClass(enable_threads && true); // TODO: fix crashes associated with this shutdo
 
 	// Image decoding
 	LLAppViewer::sImageDecodeThread = new LLImageDecodeThread(enable_threads && true);
 	LLAppViewer::sTextureCache = new LLTextureCache(enable_threads && true);
 	LLAppViewer::sTextureFetch = new LLTextureFetch(LLAppViewer::getTextureCache(),
-													sImageDecodeThread,
 													enable_threads && true,
 													app_metrics_qa_mode);
 	LLAppViewer::sPurgeDiskCacheThread = new LLPurgeDiskCacheThread();
@@ -3279,7 +3257,7 @@ LLSD LLAppViewer::getViewerInfo() const
     info["LOD_FACTOR"] = gSavedSettings.getF32("RenderVolumeLODFactor");
     info["RENDER_QUALITY"] = (F32)gSavedSettings.getU32("RenderQualityPerformance");
     info["GPU_SHADERS"] = gSavedSettings.getBOOL("RenderDeferred") ? "Enabled" : "Disabled";
-    info["TEXTURE_MEMORY"] = gSavedSettings.getS32("TextureMemory");
+    info["TEXTURE_MEMORY"] = gGLManager.mVRAM;
 
 #if LL_DARWIN
     info["HIDPI"] = gHiDPISupport;
@@ -4711,10 +4689,6 @@ void LLAppViewer::idle()
 	//
 	// Special case idle if still starting up
 	//
-	if (LLStartUp::getStartupState() >= STATE_WORLD_INIT)
-	{
-		update_texture_time();
-	}
 	if (LLStartUp::getStartupState() < STATE_STARTED)
 	{
 		// Skip rest if idle startup returns false (essentially, no world yet)
diff --git a/indra/newview/lldrawpoolterrain.cpp b/indra/newview/lldrawpoolterrain.cpp
index cc5cb667f0..be33e1b30a 100644
--- a/indra/newview/lldrawpoolterrain.cpp
+++ b/indra/newview/lldrawpoolterrain.cpp
@@ -148,7 +148,7 @@ void LLDrawPoolTerrain::boostTerrainDetailTextures()
 	for (S32 i = 0; i < 4; i++)
 	{
 		compp->mDetailTextures[i]->setBoostLevel(LLGLTexture::BOOST_TERRAIN);
-		compp->mDetailTextures[i]->addTextureStats(1024.f*1024.f); // assume large pixel area
+        gPipeline.touchTexture(compp->mDetailTextures[i], 1024.f * 1024.f);
 	}
 }
 
diff --git a/indra/newview/llface.cpp b/indra/newview/llface.cpp
index 499d8d161d..52aacb607c 100644
--- a/indra/newview/llface.cpp
+++ b/indra/newview/llface.cpp
@@ -2321,6 +2321,7 @@ void LLFace::resetVirtualSize()
 
 F32 LLFace::getTextureVirtualSize()
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	F32 radius;
 	F32 cos_angle_to_view_dir;	
 	BOOL in_frustum = calcPixelArea(cos_angle_to_view_dir, radius);
diff --git a/indra/newview/llfloaterlagmeter.cpp b/indra/newview/llfloaterlagmeter.cpp
index f72f2631a1..db00f69f03 100644
--- a/indra/newview/llfloaterlagmeter.cpp
+++ b/indra/newview/llfloaterlagmeter.cpp
@@ -179,7 +179,7 @@ void LLFloaterLagMeter::determineClient()
 		{
 			mClientCause->setText( getString("client_texture_loading_cause_msg", mStringArgs) );
 		}
-		else if(LLViewerTexture::sBoundTextureMemory > LLViewerTexture::sMaxBoundTextureMemory)
+		else if(LLViewerTexture::isMemoryForTextureLow())
 		{
 			mClientCause->setText( getString("client_texture_memory_cause_msg", mStringArgs) );
 		}
diff --git a/indra/newview/llfloaterpreference.cpp b/indra/newview/llfloaterpreference.cpp
index f1db12ddb0..34596d165b 100644
--- a/indra/newview/llfloaterpreference.cpp
+++ b/indra/newview/llfloaterpreference.cpp
@@ -1225,12 +1225,7 @@ void LLFloaterPreferenceGraphicsAdvanced::refreshEnabledState()
 	shadow_text->setEnabled(enabled);
 
 	// Hardware settings
-	F32 mem_multiplier = gSavedSettings.getF32("RenderTextureMemoryMultiple");
-	S32Megabytes min_tex_mem = LLViewerTextureList::getMinVideoRamSetting();
-	S32Megabytes max_tex_mem = LLViewerTextureList::getMaxVideoRamSetting(false, mem_multiplier);
-	getChild<LLSliderCtrl>("GraphicsCardTextureMemory")->setMinValue(min_tex_mem.value());
-	getChild<LLSliderCtrl>("GraphicsCardTextureMemory")->setMaxValue(max_tex_mem.value());
-
+	
 	if (!LLFeatureManager::getInstance()->isFeatureAvailable("RenderVBOEnable") ||
 		!gGLManager.mHasVertexBufferObject)
 	{
diff --git a/indra/newview/llfloatertexturefetchdebugger.cpp b/indra/newview/llfloatertexturefetchdebugger.cpp
deleted file mode 100644
index cda4dc8bcc..0000000000
--- a/indra/newview/llfloatertexturefetchdebugger.cpp
+++ /dev/null
@@ -1,480 +0,0 @@
-/** 
- * @file llfloatertexturefetchdebugger.cpp
- * @brief LLFloaterTextureFetchDebugger class definition
- *
- * $LicenseInfo:firstyear=2007&license=viewerlgpl$
- * Second Life Viewer Source Code
- * Copyright (C) 2012, Linden Research, Inc.
- * 
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation;
- * version 2.1 of the License only.
- * 
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- * 
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
- * 
- * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
- * $/LicenseInfo$
- */
-
-#include "llviewerprecompiledheaders.h"
-
-#include "llfloatertexturefetchdebugger.h"
-
-#include "lluictrlfactory.h"
-#include "llbutton.h"
-#include "llspinctrl.h"
-#include "llresmgr.h"
-
-#include "llmath.h"
-#include "llviewerwindow.h"
-#include "llappviewer.h"
-#include "lltexturefetch.h"
-#include "llviewercontrol.h"
-#include "llviewerassetstats.h" //gTextureTimer
-
-LLFloaterTextureFetchDebugger::LLFloaterTextureFetchDebugger(const LLSD& key)
-	: LLFloater(key),
-	mDebugger(NULL)
-{
-	setTitle("Texture Fetching Debugger Floater");
-	
-	mCommitCallbackRegistrar.add("TexFetchDebugger.ChangeTexelPixelRatio",	boost::bind(&LLFloaterTextureFetchDebugger::onChangeTexelPixelRatio, this));
-
-	mCommitCallbackRegistrar.add("TexFetchDebugger.Start",	boost::bind(&LLFloaterTextureFetchDebugger::onClickStart, this));
-	mCommitCallbackRegistrar.add("TexFetchDebugger.Clear",	boost::bind(&LLFloaterTextureFetchDebugger::onClickClear, this));
-	mCommitCallbackRegistrar.add("TexFetchDebugger.Close",	boost::bind(&LLFloaterTextureFetchDebugger::onClickClose, this));
-	mCommitCallbackRegistrar.add("TexFetchDebugger.ResetFetchTime",	boost::bind(&LLFloaterTextureFetchDebugger::onClickResetFetchTime, this));
-
-	mCommitCallbackRegistrar.add("TexFetchDebugger.CacheRead",	boost::bind(&LLFloaterTextureFetchDebugger::onClickCacheRead, this));
-	mCommitCallbackRegistrar.add("TexFetchDebugger.CacheWrite",	boost::bind(&LLFloaterTextureFetchDebugger::onClickCacheWrite, this));
-	mCommitCallbackRegistrar.add("TexFetchDebugger.HTTPLoad",	boost::bind(&LLFloaterTextureFetchDebugger::onClickHTTPLoad, this));
-	mCommitCallbackRegistrar.add("TexFetchDebugger.Decode",	boost::bind(&LLFloaterTextureFetchDebugger::onClickDecode, this));
-	mCommitCallbackRegistrar.add("TexFetchDebugger.GLTexture",	boost::bind(&LLFloaterTextureFetchDebugger::onClickGLTexture, this));
-
-	mCommitCallbackRegistrar.add("TexFetchDebugger.RefetchVisCache",	boost::bind(&LLFloaterTextureFetchDebugger::onClickRefetchVisCache, this));
-	mCommitCallbackRegistrar.add("TexFetchDebugger.RefetchVisHTTP",	boost::bind(&LLFloaterTextureFetchDebugger::onClickRefetchVisHTTP, this));
-	mCommitCallbackRegistrar.add("TexFetchDebugger.RefetchAllCache",	boost::bind(&LLFloaterTextureFetchDebugger::onClickRefetchAllCache, this));
-	mCommitCallbackRegistrar.add("TexFetchDebugger.RefetchAllHTTP",	boost::bind(&LLFloaterTextureFetchDebugger::onClickRefetchAllHTTP, this));
-}
-//----------------------------------------------
-
-BOOL LLFloaterTextureFetchDebugger::postBuild(void) 
-{	
-	mDebugger = LLAppViewer::getTextureFetch()->getFetchDebugger();
-	mStartStatus = (S32)LLTextureFetchDebugger::IDLE;
-
-	//set states for buttons
-	mButtonStateMap["start_btn"] = true;
-	mButtonStateMap["close_btn"] = true;
-	mButtonStateMap["clear_btn"] = true;
-	mButtonStateMap["cacheread_btn"] = false;
-	mButtonStateMap["cachewrite_btn"] = false;
-	mButtonStateMap["http_btn"] = false;
-	mButtonStateMap["decode_btn"] = false;
-	mButtonStateMap["gl_btn"] = false;
-
-	mButtonStateMap["refetchviscache_btn"] = false;
-	mButtonStateMap["refetchvishttp_btn"] = false;
-	mButtonStateMap["refetchallcache_btn"] = false;
-	mButtonStateMap["refetchallhttp_btn"] = false;
-
-	updateButtons();
-
-	getChild<LLUICtrl>("texel_pixel_ratio")->setValue(gSavedSettings.getF32("TexelPixelRatio"));
-
-	return TRUE ;
-}
-
-LLFloaterTextureFetchDebugger::~LLFloaterTextureFetchDebugger()
-{
-	//stop everything
-	mDebugger->setStopDebug();
-}
-
-void LLFloaterTextureFetchDebugger::updateButtons()
-{
-	for(std::map<std::string, bool>::iterator iter = mButtonStateMap.begin(); iter != mButtonStateMap.end(); ++iter)
-	{
-		if(iter->second)
-		{
-			childEnable(iter->first.c_str());
-		}
-		else
-		{
-			childDisable(iter->first.c_str());
-		}
-	}
-}
-
-void LLFloaterTextureFetchDebugger::disableButtons()
-{
-	childDisable("start_btn");
-	childDisable("clear_btn");
-	childDisable("cacheread_btn");
-	childDisable("cachewrite_btn");
-	childDisable("http_btn");
-	childDisable("decode_btn");
-	childDisable("gl_btn");
-	childDisable("refetchviscache_btn");
-	childDisable("refetchvishttp_btn");
-	childDisable("refetchallcache_btn");
-	childDisable("refetchallhttp_btn");
-}
-void LLFloaterTextureFetchDebugger::setStartStatus(S32 status)
-{
-	llassert_always(LLTextureFetchDebugger::IDLE == (LLTextureFetchDebugger::e_debug_state)mStartStatus) ;
-	mStartStatus = status;
-}
-	
-bool LLFloaterTextureFetchDebugger::idleStart()
-{
-	if(mStartStatus != (S32)LLTextureFetchDebugger::IDLE)
-	{
-		mDebugger->startWork((LLTextureFetchDebugger::e_debug_state)mStartStatus);
-		mStartStatus = (S32)LLTextureFetchDebugger::IDLE;
-		return true;
-	}
-
-	return false;
-}
-
-void LLFloaterTextureFetchDebugger::idle()
-{	
-	if(idleStart())
-	{
-		return;
-	}
-
-	const F32 max_time = 0.005f; //5ms
-	LLTextureFetchDebugger::e_debug_state state = mDebugger->getState();	
-	if(mDebugger->update(max_time))
-	{
-		switch(state)
-		{
-		case LLTextureFetchDebugger::IDLE:
-			break;
-		case LLTextureFetchDebugger::START_DEBUG:
-			mButtonStateMap["cacheread_btn"] = true;
-			mButtonStateMap["http_btn"] = true;
-			mButtonStateMap["refetchviscache_btn"] = true;
-			mButtonStateMap["refetchvishttp_btn"] = true;
-			mButtonStateMap["refetchallcache_btn"] = true;
-			mButtonStateMap["refetchallhttp_btn"] = true;
-			break;
-		case LLTextureFetchDebugger::READ_CACHE:			
-			mButtonStateMap["decode_btn"] = true;			
-			break;
-		case LLTextureFetchDebugger::WRITE_CACHE:			
-			break;
-		case LLTextureFetchDebugger::DECODING:
-			mButtonStateMap["gl_btn"] = true;			
-			break;
-		case LLTextureFetchDebugger::HTTP_FETCHING:
-			mButtonStateMap["cacheread_btn"] = true;
-			mButtonStateMap["cachewrite_btn"] = true;
-			mButtonStateMap["decode_btn"] = true;			
-			break;
-		case LLTextureFetchDebugger::GL_TEX:			
-			break;
-		case LLTextureFetchDebugger::REFETCH_VIS_CACHE:			
-			break;
-		case LLTextureFetchDebugger::REFETCH_VIS_HTTP:			
-			break;
-		case LLTextureFetchDebugger::REFETCH_ALL_CACHE:			
-			break;
-		case LLTextureFetchDebugger::REFETCH_ALL_HTTP:
-			break;
-		default:
-			break;
-		}
-
-		if(state != LLTextureFetchDebugger::IDLE)
-		{
-			updateButtons();
-		}
-	}
-}
-
-//----------------------
-void LLFloaterTextureFetchDebugger::onChangeTexelPixelRatio()
-{
-	gSavedSettings.setF32("TexelPixelRatio", getChild<LLUICtrl>("texel_pixel_ratio")->getValue().asReal());
-}
-
-void LLFloaterTextureFetchDebugger::onClickStart()
-{
-	disableButtons();
-
-	setStartStatus((S32)LLTextureFetchDebugger::START_DEBUG);	
-
-	mButtonStateMap["start_btn"] = false;
-
-	updateButtons();
-}
-
-void LLFloaterTextureFetchDebugger::onClickClose()
-{
-	setVisible(FALSE);
-	
-	//stop everything
-	mDebugger->setStopDebug();
-
-	delete this;
-}
-
-void LLFloaterTextureFetchDebugger::onClickResetFetchTime()
-{
-	gTextureTimer.start();
-	gTextureTimer.pause();
-}
-
-void LLFloaterTextureFetchDebugger::onClickClear()
-{
-	mButtonStateMap["start_btn"] = true;
-	mButtonStateMap["close_btn"] = true;
-	mButtonStateMap["clear_btn"] = true;
-	mButtonStateMap["cacheread_btn"] = false;
-	mButtonStateMap["cachewrite_btn"] = false;
-	mButtonStateMap["http_btn"] = false;
-	mButtonStateMap["decode_btn"] = false;
-	mButtonStateMap["gl_btn"] = false;
-	mButtonStateMap["refetchviscache_btn"] = true;
-	mButtonStateMap["refetchvishttp_btn"] = true;
-	updateButtons();
-
-	//stop everything
-	mDebugger->setStopDebug();
-	mDebugger->clearHistory();
-}
-
-void LLFloaterTextureFetchDebugger::onClickCacheRead()
-{
-	disableButtons();
-
-	setStartStatus((S32)LLTextureFetchDebugger::READ_CACHE);
-}
-
-void LLFloaterTextureFetchDebugger::onClickCacheWrite()
-{
-	disableButtons();
-
-	setStartStatus((S32)LLTextureFetchDebugger::WRITE_CACHE);
-}
-
-void LLFloaterTextureFetchDebugger::onClickHTTPLoad()
-{
-	disableButtons();
-
-	setStartStatus((S32)LLTextureFetchDebugger::HTTP_FETCHING);
-}
-
-void LLFloaterTextureFetchDebugger::onClickDecode()
-{
-	disableButtons();
-
-	setStartStatus((S32)LLTextureFetchDebugger::DECODING);
-}
-
-void LLFloaterTextureFetchDebugger::onClickGLTexture()
-{
-	disableButtons();
-
-	setStartStatus((S32)LLTextureFetchDebugger::GL_TEX);	
-}
-
-void LLFloaterTextureFetchDebugger::onClickRefetchVisCache()
-{
-	disableButtons();
-
-	setStartStatus((S32)LLTextureFetchDebugger::REFETCH_VIS_CACHE);
-}
-
-void LLFloaterTextureFetchDebugger::onClickRefetchVisHTTP()
-{
-	disableButtons();
-
-	setStartStatus((S32)LLTextureFetchDebugger::REFETCH_VIS_HTTP);	
-}
-
-void LLFloaterTextureFetchDebugger::onClickRefetchAllCache()
-{
-	disableButtons();
-
-	setStartStatus((S32)LLTextureFetchDebugger::REFETCH_ALL_CACHE);
-}
-
-void LLFloaterTextureFetchDebugger::onClickRefetchAllHTTP()
-{
-	disableButtons();
-
-	setStartStatus((S32)LLTextureFetchDebugger::REFETCH_ALL_HTTP);	
-}
-
-void LLFloaterTextureFetchDebugger::draw()
-{
-	//total number of fetched textures
-	{
-		getChild<LLUICtrl>("total_num_fetched_label")->setTextArg("[NUM]", llformat("%d", mDebugger->getNumFetchedTextures()));
-	}
-
-	//total number of fetching requests
-	{
-		getChild<LLUICtrl>("total_num_fetching_requests_label")->setTextArg("[NUM]", llformat("%d", mDebugger->getNumFetchingRequests()));
-	}
-
-	//total number of cache hits
-	{
-		getChild<LLUICtrl>("total_num_cache_hits_label")->setTextArg("[NUM]", llformat("%d", mDebugger->getNumCacheHits()));
-	}
-
-	//total number of visible textures
-	{
-		getChild<LLUICtrl>("total_num_visible_tex_label")->setTextArg("[NUM]", llformat("%d", mDebugger->getNumVisibleFetchedTextures()));
-	}
-
-	//total number of visible texture fetching requests
-	{
-		getChild<LLUICtrl>("total_num_visible_tex_fetch_req_label")->setTextArg("[NUM]", llformat("%d", mDebugger->getNumVisibleFetchingRequests()));
-	}
-
-	//total number of fetched data
-	{
-		getChild<LLUICtrl>("total_fetched_data_label")->setTextArg("[SIZE1]", llformat("%d", mDebugger->getFetchedData() >> 10));		
-		getChild<LLUICtrl>("total_fetched_data_label")->setTextArg("[SIZE2]", llformat("%d", mDebugger->getDecodedData() >> 10));
-		getChild<LLUICtrl>("total_fetched_data_label")->setTextArg("[PIXEL]", llformat("%.3f", mDebugger->getFetchedPixels() / 1000000.f));
-	}
-
-	//total number of visible fetched data
-	{		
-		getChild<LLUICtrl>("total_fetched_vis_data_label")->setTextArg("[SIZE1]", llformat("%d", mDebugger->getVisibleFetchedData() >> 10));		
-		getChild<LLUICtrl>("total_fetched_vis_data_label")->setTextArg("[SIZE2]", llformat("%d", mDebugger->getVisibleDecodedData() >> 10));
-	}
-
-	//total number of rendered fetched data
-	{
-		getChild<LLUICtrl>("total_fetched_rendered_data_label")->setTextArg("[SIZE1]", llformat("%d", mDebugger->getRenderedData() >> 10));		
-		getChild<LLUICtrl>("total_fetched_rendered_data_label")->setTextArg("[SIZE2]", llformat("%d", mDebugger->getRenderedDecodedData() >> 10));
-		getChild<LLUICtrl>("total_fetched_rendered_data_label")->setTextArg("[PIXEL]", llformat("%.3f", mDebugger->getRenderedPixels() / 1000000.f));
-	}
-
-	//total time on cache readings
-	if(mDebugger->getCacheReadTime() < 0.f)
-	{
-		getChild<LLUICtrl>("total_time_cache_read_label")->setTextArg("[TIME]", std::string("----"));
-	}
-	else
-	{
-		getChild<LLUICtrl>("total_time_cache_read_label")->setTextArg("[TIME]", llformat("%.3f", mDebugger->getCacheReadTime()));
-	}
-
-	//total time on cache writings
-	if(mDebugger->getCacheWriteTime() < 0.f)
-	{
-		getChild<LLUICtrl>("total_time_cache_write_label")->setTextArg("[TIME]", std::string("----"));
-	}
-	else
-	{
-		getChild<LLUICtrl>("total_time_cache_write_label")->setTextArg("[TIME]", llformat("%.3f", mDebugger->getCacheWriteTime()));
-	}
-
-	//total time on decoding
-	if(mDebugger->getDecodeTime() < 0.f)
-	{
-		getChild<LLUICtrl>("total_time_decode_label")->setTextArg("[TIME]", std::string("----"));
-	}
-	else
-	{
-		getChild<LLUICtrl>("total_time_decode_label")->setTextArg("[TIME]", llformat("%.3f", mDebugger->getDecodeTime()));
-	}
-
-	//total time on gl texture creation
-	if(mDebugger->getGLCreationTime() < 0.f)
-	{
-		getChild<LLUICtrl>("total_time_gl_label")->setTextArg("[TIME]", std::string("----"));
-	}
-	else
-	{
-		getChild<LLUICtrl>("total_time_gl_label")->setTextArg("[TIME]", llformat("%.3f", mDebugger->getGLCreationTime()));
-	}
-
-	//total time on HTTP fetching
-	if(mDebugger->getHTTPTime() < 0.f)
-	{
-		getChild<LLUICtrl>("total_time_http_label")->setTextArg("[TIME]", std::string("----"));
-	}
-	else
-	{
-		getChild<LLUICtrl>("total_time_http_label")->setTextArg("[TIME]", llformat("%.3f", mDebugger->getHTTPTime()));
-	}
-
-	//total time on entire fetching
-	{
-		getChild<LLUICtrl>("total_time_fetch_label")->setTextArg("[TIME]", llformat("%.3f", mDebugger->getTotalFetchingTime()));
-	}
-
-	//total time on refetching visible textures from cache
-	if(mDebugger->getRefetchVisCacheTime() < 0.f)
-	{
-		getChild<LLUICtrl>("total_time_refetch_vis_cache_label")->setTextArg("[TIME]", std::string("----"));
-		getChild<LLUICtrl>("total_time_refetch_vis_cache_label")->setTextArg("[SIZE]", std::string("----"));
-		getChild<LLUICtrl>("total_time_refetch_vis_cache_label")->setTextArg("[PIXEL]", std::string("----"));
-	}
-	else
-	{
-		getChild<LLUICtrl>("total_time_refetch_vis_cache_label")->setTextArg("[TIME]", llformat("%.3f", mDebugger->getRefetchVisCacheTime()));
-		getChild<LLUICtrl>("total_time_refetch_vis_cache_label")->setTextArg("[SIZE]", llformat("%d", mDebugger->getRefetchedVisData() >> 10));
-		getChild<LLUICtrl>("total_time_refetch_vis_cache_label")->setTextArg("[PIXEL]", llformat("%.3f", mDebugger->getRefetchedVisPixels() / 1000000.f));
-	}
-
-	//total time on refetching all textures from cache
-	if(mDebugger->getRefetchAllCacheTime() < 0.f)
-	{
-		getChild<LLUICtrl>("total_time_refetch_all_cache_label")->setTextArg("[TIME]", std::string("----"));
-		getChild<LLUICtrl>("total_time_refetch_all_cache_label")->setTextArg("[SIZE]", std::string("----"));
-		getChild<LLUICtrl>("total_time_refetch_all_cache_label")->setTextArg("[PIXEL]", std::string("----"));
-	}
-	else
-	{
-		getChild<LLUICtrl>("total_time_refetch_all_cache_label")->setTextArg("[TIME]", llformat("%.3f", mDebugger->getRefetchAllCacheTime()));
-		getChild<LLUICtrl>("total_time_refetch_all_cache_label")->setTextArg("[SIZE]", llformat("%d", mDebugger->getRefetchedAllData() >> 10));
-		getChild<LLUICtrl>("total_time_refetch_all_cache_label")->setTextArg("[PIXEL]", llformat("%.3f", mDebugger->getRefetchedAllPixels() / 1000000.f));
-	}
-
-	//total time on refetching visible textures from http
-	if(mDebugger->getRefetchVisHTTPTime() < 0.f)
-	{
-		getChild<LLUICtrl>("total_time_refetch_vis_http_label")->setTextArg("[TIME]", std::string("----"));
-		getChild<LLUICtrl>("total_time_refetch_vis_http_label")->setTextArg("[SIZE]", std::string("----"));
-		getChild<LLUICtrl>("total_time_refetch_vis_http_label")->setTextArg("[PIXEL]", std::string("----"));
-	}
-	else
-	{
-		getChild<LLUICtrl>("total_time_refetch_vis_http_label")->setTextArg("[TIME]", llformat("%.3f", mDebugger->getRefetchVisHTTPTime()));
-		getChild<LLUICtrl>("total_time_refetch_vis_http_label")->setTextArg("[SIZE]", llformat("%d", mDebugger->getRefetchedVisData() >> 10));
-		getChild<LLUICtrl>("total_time_refetch_vis_http_label")->setTextArg("[PIXEL]", llformat("%.3f", mDebugger->getRefetchedVisPixels() / 1000000.f));
-	}
-
-	//total time on refetching all textures from http
-	if(mDebugger->getRefetchAllHTTPTime() < 0.f)
-	{
-		getChild<LLUICtrl>("total_time_refetch_all_http_label")->setTextArg("[TIME]", std::string("----"));
-		getChild<LLUICtrl>("total_time_refetch_all_http_label")->setTextArg("[SIZE]", std::string("----"));
-		getChild<LLUICtrl>("total_time_refetch_all_http_label")->setTextArg("[PIXEL]", std::string("----"));
-	}
-	else
-	{
-		getChild<LLUICtrl>("total_time_refetch_all_http_label")->setTextArg("[TIME]", llformat("%.3f", mDebugger->getRefetchAllHTTPTime()));
-		getChild<LLUICtrl>("total_time_refetch_all_http_label")->setTextArg("[SIZE]", llformat("%d", mDebugger->getRefetchedAllData() >> 10));
-		getChild<LLUICtrl>("total_time_refetch_all_http_label")->setTextArg("[PIXEL]", llformat("%.3f", mDebugger->getRefetchedAllPixels() / 1000000.f));
-	}
-
-	LLFloater::draw();
-}
diff --git a/indra/newview/llfloatertexturefetchdebugger.h b/indra/newview/llfloatertexturefetchdebugger.h
deleted file mode 100644
index 637f3b03e5..0000000000
--- a/indra/newview/llfloatertexturefetchdebugger.h
+++ /dev/null
@@ -1,77 +0,0 @@
-/** 
- * @file llfloatertexturefetchdebugger.h
- * @brief texture fetching debugger window, debug use only
- *
- * $LicenseInfo:firstyear=2004&license=viewerlgpl$
- * Second Life Viewer Source Code
- * Copyright (C) 2010, Linden Research, Inc.
- * 
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation;
- * version 2.1 of the License only.
- * 
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- * 
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
- * 
- * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
- * $/LicenseInfo$
- */
-
-#ifndef LL_FLOATER_TEXTURE_FETCH_DEBUGGER__H
-#define LL_FLOATER_TEXTURE_FETCH_DEBUGGER__H
-
-#include "llfloater.h"
-class LLTextureFetchDebugger;
-
-class LLFloaterTextureFetchDebugger : public LLFloater
-{
-	friend class LLFloaterReg;
-public:
-	/// initialize all the callbacks for the menu
-
-	virtual BOOL postBuild() ;
-	virtual void draw() ;
-	
-	void onChangeTexelPixelRatio();
-	
-	void onClickStart();
-	void onClickClear();
-	void onClickClose();
-	void onClickResetFetchTime();
-
-	void onClickCacheRead();
-	void onClickCacheWrite();
-	void onClickHTTPLoad();
-	void onClickDecode();
-	void onClickGLTexture();
-
-	void onClickRefetchVisCache();
-	void onClickRefetchVisHTTP();
-	void onClickRefetchAllCache();
-	void onClickRefetchAllHTTP();
-public:
-	void idle() ;
-
-private:	
-	LLFloaterTextureFetchDebugger(const LLSD& key);
-	virtual ~LLFloaterTextureFetchDebugger();
-
-	void updateButtons();
-	void disableButtons();
-
-	void setStartStatus(S32 status);
-	bool idleStart();
-private:	
-	LLTextureFetchDebugger* mDebugger;
-	std::map<std::string, bool> mButtonStateMap;
-	S32 mStartStatus;
-};
-
-#endif // LL_FLOATER_TEXTURE_FETCH_DEBUGGER__H
diff --git a/indra/newview/llinventorymodel.cpp b/indra/newview/llinventorymodel.cpp
index 37500176ea..c101033a5d 100644
--- a/indra/newview/llinventorymodel.cpp
+++ b/indra/newview/llinventorymodel.cpp
@@ -222,8 +222,6 @@ LLInventoryModel::LLInventoryModel()
 	mHttpOptions(),
 	mHttpHeaders(),
 	mHttpPolicyClass(LLCore::HttpRequest::DEFAULT_POLICY_ID),
-	mHttpPriorityFG(0),
-	mHttpPriorityBG(0),
 	mCategoryLock(),
 	mItemLock(),
 	mValidationInfo(new LLInventoryValidationInfo)
@@ -2799,7 +2797,6 @@ LLCore::HttpHandle LLInventoryModel::requestPost(bool foreground,
 		
 	handle = LLCoreHttpUtil::requestPostWithLLSD(request,
 												 mHttpPolicyClass,
-												 (foreground ? mHttpPriorityFG : mHttpPriorityBG),
 												 url,
 												 body,
 												 mHttpOptions,
diff --git a/indra/newview/llinventorymodel.h b/indra/newview/llinventorymodel.h
index eeec89bfb0..85343cf95c 100644
--- a/indra/newview/llinventorymodel.h
+++ b/indra/newview/llinventorymodel.h
@@ -617,8 +617,6 @@ private:
 	LLCore::HttpOptions::ptr_t			mHttpOptions;
 	LLCore::HttpHeaders::ptr_t			mHttpHeaders;
 	LLCore::HttpRequest::policy_t		mHttpPolicyClass;
-	LLCore::HttpRequest::priority_t		mHttpPriorityFG;
-	LLCore::HttpRequest::priority_t		mHttpPriorityBG;
 	
 /**                    HTTP Transport
  **                                                                            **
diff --git a/indra/newview/llmaterialmgr.cpp b/indra/newview/llmaterialmgr.cpp
index 11aa607393..27a9758ec3 100644
--- a/indra/newview/llmaterialmgr.cpp
+++ b/indra/newview/llmaterialmgr.cpp
@@ -133,8 +133,7 @@ LLMaterialMgr::LLMaterialMgr():
 	mHttpRequest(),
 	mHttpHeaders(),
 	mHttpOptions(),
-	mHttpPolicy(LLCore::HttpRequest::DEFAULT_POLICY_ID),
-	mHttpPriority(0)
+	mHttpPolicy(LLCore::HttpRequest::DEFAULT_POLICY_ID)
 {
 	LLAppCoreHttp & app_core_http(LLAppViewer::instance()->getAppCoreHttp());
 
@@ -699,7 +698,7 @@ void LLMaterialMgr::processGetQueue()
 			<< "\ndata: " << ll_pretty_print_sd(materialsData) << LL_ENDL;
 
 		LLCore::HttpHandle handle = LLCoreHttpUtil::requestPostWithLLSD(mHttpRequest, 
-				mHttpPolicy, mHttpPriority, capURL, 
+				mHttpPolicy, capURL, 
 				postData, mHttpOptions, mHttpHeaders, handler);
 
 		if (handle == LLCORE_HTTP_HANDLE_INVALID)
@@ -985,7 +984,7 @@ void LLMaterialMgr::processPutQueue()
 										));
 
 			LLCore::HttpHandle handle = LLCoreHttpUtil::requestPutWithLLSD(
-				mHttpRequest, mHttpPolicy, mHttpPriority, capURL,
+				mHttpRequest, mHttpPolicy, capURL,
 				putData, mHttpOptions, mHttpHeaders, handler);
 
 			if (handle == LLCORE_HTTP_HANDLE_INVALID)
diff --git a/indra/newview/llmaterialmgr.h b/indra/newview/llmaterialmgr.h
index 843dc66fbc..f76cc27db1 100644
--- a/indra/newview/llmaterialmgr.h
+++ b/indra/newview/llmaterialmgr.h
@@ -141,7 +141,6 @@ private:
 	LLCore::HttpHeaders::ptr_t		mHttpHeaders;
 	LLCore::HttpOptions::ptr_t		mHttpOptions;
 	LLCore::HttpRequest::policy_t	mHttpPolicy;
-	LLCore::HttpRequest::priority_t	mHttpPriority;
 
 	U32 getMaxEntries(const LLViewerRegion* regionp);
 };
diff --git a/indra/newview/llmediadataclient.cpp b/indra/newview/llmediadataclient.cpp
index bc45eb6d3a..142977e939 100644
--- a/indra/newview/llmediadataclient.cpp
+++ b/indra/newview/llmediadataclient.cpp
@@ -355,7 +355,7 @@ void LLMediaDataClient::serviceQueue()
 		
 		// and make the post
         LLCore::HttpHandler::ptr_t handler = request->createHandler();
-        LLCore::HttpHandle handle = LLCoreHttpUtil::requestPostWithLLSD(mHttpRequest, mHttpPolicy, 0,
+        LLCore::HttpHandle handle = LLCoreHttpUtil::requestPostWithLLSD(mHttpRequest, mHttpPolicy,
             url, sd_payload, mHttpOpts, mHttpHeaders, handler);
 
         if (handle == LLCORE_HTTP_HANDLE_INVALID)
diff --git a/indra/newview/llmeshrepository.cpp b/indra/newview/llmeshrepository.cpp
index d28e929b48..6fa71e130e 100644
--- a/indra/newview/llmeshrepository.cpp
+++ b/indra/newview/llmeshrepository.cpp
@@ -823,8 +823,7 @@ LLMeshRepoThread::LLMeshRepoThread()
   mHttpLargeOptions(),
   mHttpHeaders(),
   mHttpPolicyClass(LLCore::HttpRequest::DEFAULT_POLICY_ID),
-  mHttpLargePolicyClass(LLCore::HttpRequest::DEFAULT_POLICY_ID),
-  mHttpPriority(0)
+  mHttpLargePolicyClass(LLCore::HttpRequest::DEFAULT_POLICY_ID)
 {
 	LLAppCoreHttp & app_core_http(LLAppViewer::instance()->getAppCoreHttp());
 
@@ -1268,7 +1267,6 @@ LLCore::HttpHandle LLMeshRepoThread::getByteRange(const std::string & url,
 	if (len < LARGE_MESH_FETCH_THRESHOLD)
 	{
 		handle = mHttpRequest->requestGetByteRange( mHttpPolicyClass,
-                                                    mHttpPriority,
                                                     url,
                                                     (disable_range_req ? size_t(0) : offset),
                                                     (disable_range_req ? size_t(0) : len),
@@ -1283,7 +1281,6 @@ LLCore::HttpHandle LLMeshRepoThread::getByteRange(const std::string & url,
 	else
 	{
 		handle = mHttpRequest->requestGetByteRange(mHttpLargePolicyClass,
-												   mHttpPriority,
 												   url,
 												   (disable_range_req ? size_t(0) : offset),
 												   (disable_range_req ? size_t(0) : len),
@@ -2130,7 +2127,6 @@ LLMeshUploadThread::LLMeshUploadThread(LLMeshUploadThread::instance_list& data,
 	mHttpHeaders = LLCore::HttpHeaders::ptr_t(new LLCore::HttpHeaders);
 	mHttpHeaders->append(HTTP_OUT_HEADER_CONTENT_TYPE, HTTP_CONTENT_LLSD_XML);
 	mHttpPolicyClass = LLAppViewer::instance()->getAppCoreHttp().getPolicy(LLAppCoreHttp::AP_UPLOADS);
-	mHttpPriority = 0;
 }
 
 LLMeshUploadThread::~LLMeshUploadThread()
@@ -2649,7 +2645,6 @@ void LLMeshUploadThread::doWholeModelUpload()
 
 		LLCore::HttpHandle handle = LLCoreHttpUtil::requestPostWithLLSD(mHttpRequest,
 																		mHttpPolicyClass,
-																		mHttpPriority,
 																		mWholeModelUploadURL,
 																		body,
 																		mHttpOptions,
@@ -2700,7 +2695,6 @@ void LLMeshUploadThread::requestWholeModelFee()
 	dump_llsd_to_file(mModelData, make_dump_name("whole_model_fee_request_", dump_num));
 	LLCore::HttpHandle handle = LLCoreHttpUtil::requestPostWithLLSD(mHttpRequest,
 																	mHttpPolicyClass,
-																	mHttpPriority,
 																	mWholeModelFeeCapability,
 																	mModelData,
 																	mHttpOptions,
diff --git a/indra/newview/llmeshrepository.h b/indra/newview/llmeshrepository.h
index 1989350303..5459bbb4af 100644
--- a/indra/newview/llmeshrepository.h
+++ b/indra/newview/llmeshrepository.h
@@ -321,7 +321,6 @@ public:
 	LLCore::HttpHeaders::ptr_t			mHttpHeaders;
 	LLCore::HttpRequest::policy_t		mHttpPolicyClass;
 	LLCore::HttpRequest::policy_t		mHttpLargePolicyClass;
-	LLCore::HttpRequest::priority_t		mHttpPriority;
 
 	typedef std::set<LLCore::HttpHandler::ptr_t> http_request_set;
 	http_request_set					mHttpRequestSet;			// Outstanding HTTP requests
@@ -489,7 +488,6 @@ private:
 	LLCore::HttpOptions::ptr_t			mHttpOptions;
 	LLCore::HttpHeaders::ptr_t			mHttpHeaders;
 	LLCore::HttpRequest::policy_t		mHttpPolicyClass;
-	LLCore::HttpRequest::priority_t		mHttpPriority;
 };
 
 // Params related to streaming cost, render cost, and scene complexity tracking.
diff --git a/indra/newview/llspatialpartition.cpp b/indra/newview/llspatialpartition.cpp
index f445bc98eb..10b3683cc8 100644
--- a/indra/newview/llspatialpartition.cpp
+++ b/indra/newview/llspatialpartition.cpp
@@ -3367,10 +3367,10 @@ public:
 				}
 			}	
 
-			if (drawable->getVOVolume() && gPipeline.hasRenderDebugMask(LLPipeline::RENDER_DEBUG_TEXTURE_PRIORITY))
+			/*if (drawable->getVOVolume() && gPipeline.hasRenderDebugMask(LLPipeline::RENDER_DEBUG_TEXTURE_PRIORITY))
 			{
 				renderTexturePriority(drawable);
-			}
+			}*/
 
 			if (gPipeline.hasRenderDebugMask(LLPipeline::RENDER_DEBUG_POINTS))
 			{
@@ -3697,7 +3697,7 @@ void LLSpatialPartition::renderDebug()
 									  LLPipeline::RENDER_DEBUG_BBOXES |
 									  LLPipeline::RENDER_DEBUG_NORMALS |
 									  LLPipeline::RENDER_DEBUG_POINTS |
-									  LLPipeline::RENDER_DEBUG_TEXTURE_PRIORITY |
+									  //LLPipeline::RENDER_DEBUG_TEXTURE_PRIORITY |
 									  LLPipeline::RENDER_DEBUG_TEXTURE_ANIM |
 									  LLPipeline::RENDER_DEBUG_RAYCAST |
 									  LLPipeline::RENDER_DEBUG_AVATAR_VOLUME |
diff --git a/indra/newview/lltexturecache.cpp b/indra/newview/lltexturecache.cpp
index d4fc6f3de2..8f4eb9438b 100644
--- a/indra/newview/lltexturecache.cpp
+++ b/indra/newview/lltexturecache.cpp
@@ -95,14 +95,13 @@ private:
 	};
 	
 public:
-	LLTextureCacheWorker(LLTextureCache* cache, U32 priority, const LLUUID& id,
+	LLTextureCacheWorker(LLTextureCache* cache, const LLUUID& id,
 						 U8* data, S32 datasize, S32 offset,
 						 S32 imagesize, // for writes
 						 LLTextureCache::Responder* responder)
 		: LLWorkerClass(cache, "LLTextureCacheWorker"),
 		  mID(id),
 		  mCache(cache),
-		  mPriority(priority),
 		  mReadData(NULL),
 		  mWriteData(data),
 		  mDataSize(datasize),
@@ -115,7 +114,6 @@ public:
 		  mBytesToRead(0),
 		  mBytesRead(0)
 	{
-		mPriority &= LLWorkerThread::PRIORITY_LOWBITS;
 	}
 	~LLTextureCacheWorker()
 	{
@@ -129,13 +127,12 @@ public:
 
 	virtual bool doWork(S32 param); // Called from LLWorkerThread::processRequest()
 
-	handle_t read() { addWork(0, LLWorkerThread::PRIORITY_HIGH | mPriority); return mRequestHandle; }
-	handle_t write() { addWork(1, LLWorkerThread::PRIORITY_HIGH | mPriority); return mRequestHandle; }
+	handle_t read() { addWork(0); return mRequestHandle; }
+	handle_t write() { addWork(1); return mRequestHandle; }
 	bool complete() { return checkWork(); }
 	void ioComplete(S32 bytes)
 	{
 		mBytesRead = bytes;
-		setPriority(LLWorkerThread::PRIORITY_HIGH | mPriority);
 	}
 
 private:
@@ -145,7 +142,6 @@ private:
 
 protected:
 	LLTextureCache* mCache;
-	U32 mPriority;
 	LLUUID	mID;
 	
 	U8* mReadData;
@@ -164,11 +160,11 @@ protected:
 class LLTextureCacheLocalFileWorker : public LLTextureCacheWorker
 {
 public:
-	LLTextureCacheLocalFileWorker(LLTextureCache* cache, U32 priority, const std::string& filename, const LLUUID& id,
+	LLTextureCacheLocalFileWorker(LLTextureCache* cache, const std::string& filename, const LLUUID& id,
 						 U8* data, S32 datasize, S32 offset,
 						 S32 imagesize, // for writes
 						 LLTextureCache::Responder* responder) 
-			: LLTextureCacheWorker(cache, priority, id, data, datasize, offset, imagesize, responder),
+			: LLTextureCacheWorker(cache, id, data, datasize, offset, imagesize, responder),
 			mFileName(filename)
 
 	{
@@ -183,6 +179,7 @@ private:
 
 bool LLTextureCacheLocalFileWorker::doRead()
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	S32 local_size = LLAPRFile::size(mFileName, mCache->getLocalAPRFilePool());
 
 	if (local_size > 0 && mFileName.size() > 4)
@@ -207,50 +204,6 @@ bool LLTextureCacheLocalFileWorker::doRead()
 		return true;
 	}
 
-#if USE_LFS_READ
-	if (mFileHandle == LLLFSThread::nullHandle())
-	{
-		mImageLocal = TRUE;
-		mImageSize = local_size;
-		if (!mDataSize || mDataSize + mOffset > local_size)
-		{
-			mDataSize = local_size - mOffset;
-		}
-		if (mDataSize <= 0)
-		{
-			// no more data to read
-			mDataSize = 0;
-			return true;
-		}
-		mReadData = (U8*)ALLOCATE_MEM(LLImageBase::getPrivatePool(), mDataSize);
-		mBytesRead = -1;
-		mBytesToRead = mDataSize;
-		setPriority(LLWorkerThread::PRIORITY_LOW | mPriority);
-		mFileHandle = LLLFSThread::sLocal->read(local_filename, mReadData, mOffset, mDataSize,
-												new ReadResponder(mCache, mRequestHandle));
-		return false;
-	}
-	else
-	{
-		if (mBytesRead >= 0)
-		{
-			if (mBytesRead != mBytesToRead)
-			{
-// 				LL_WARNS() << "Error reading file from local cache: " << local_filename
-// 						<< " Bytes: " << mDataSize << " Offset: " << mOffset
-// 						<< " / " << mDataSize << LL_ENDL;
-				mDataSize = 0; // failed
-				ll_aligned_free_16(mReadData);
-				mReadData = NULL;
-			}
-			return true;
-		}
-		else
-		{
-			return false;
-		}
-	}
-#else
 	if (!mDataSize || mDataSize > local_size)
 	{
 		mDataSize = local_size;
@@ -274,7 +227,6 @@ bool LLTextureCacheLocalFileWorker::doRead()
 		mImageLocal = TRUE;
 	}
 	return true;
-#endif
 }
 
 bool LLTextureCacheLocalFileWorker::doWrite()
@@ -286,12 +238,12 @@ bool LLTextureCacheLocalFileWorker::doWrite()
 class LLTextureCacheRemoteWorker : public LLTextureCacheWorker
 {
 public:
-	LLTextureCacheRemoteWorker(LLTextureCache* cache, U32 priority, const LLUUID& id,
+	LLTextureCacheRemoteWorker(LLTextureCache* cache, const LLUUID& id,
 						 U8* data, S32 datasize, S32 offset,
 						 S32 imagesize, // for writes
 						 LLPointer<LLImageRaw> raw, S32 discardlevel,
 						 LLTextureCache::Responder* responder) 
-			: LLTextureCacheWorker(cache, priority, id, data, datasize, offset, imagesize, responder),
+			: LLTextureCacheWorker(cache, id, data, datasize, offset, imagesize, responder),
 			mState(INIT),
 			mRawImage(raw),
 			mRawDiscardLevel(discardlevel)
@@ -329,6 +281,7 @@ void LLTextureCacheWorker::startWork(S32 param)
 // - the code supports offset reading but this is actually never exercised in the viewer
 bool LLTextureCacheRemoteWorker::doRead()
 {
+    LL_PROFILE_ZONE_SCOPED;
 	bool done = false;
 	S32 idx = -1;
 
@@ -580,6 +533,7 @@ bool LLTextureCacheRemoteWorker::doRead()
 // - the code *does not* support offset writing so there are no difference between buffer addresses and start of data
 bool LLTextureCacheRemoteWorker::doWrite()
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	bool done = false;
 	S32 idx = -1;	
 
@@ -756,6 +710,7 @@ bool LLTextureCacheRemoteWorker::doWrite()
 //virtual
 bool LLTextureCacheWorker::doWork(S32 param)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	bool res = false;
 	if (param == 0) // read
 	{
@@ -775,11 +730,13 @@ bool LLTextureCacheWorker::doWork(S32 param)
 //virtual (WORKER THREAD)
 void LLTextureCacheWorker::finishWork(S32 param, bool completed)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	if (mResponder.notNull())
 	{
 		bool success = (completed && mDataSize > 0);
 		if (param == 0)
 		{
+            LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("tcwfw - read");
 			// read
 			if (success)
 			{
@@ -789,12 +746,14 @@ void LLTextureCacheWorker::finishWork(S32 param, bool completed)
 			}
 			else
 			{
+                LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("tcwfw - read fail");
 				ll_aligned_free_16(mReadData);
 				mReadData = NULL;
 			}
 		}
 		else
 		{
+            LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("tcwfw - write");
 			// write
 			mWriteData = NULL; // we never owned data
 			mDataSize = 0;
@@ -806,6 +765,7 @@ void LLTextureCacheWorker::finishWork(S32 param, bool completed)
 //virtual (MAIN THREAD)
 void LLTextureCacheWorker::endWork(S32 param, bool aborted)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	if (aborted)
 	{
 		// Let the destructor handle any cleanup
@@ -861,6 +821,7 @@ LLTextureCache::~LLTextureCache()
 //virtual
 S32 LLTextureCache::update(F32 max_time_ms)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	static LLFrameTimer timer ;
 	static const F32 MAX_TIME_INTERVAL = 300.f ; //seconds.
 
@@ -874,22 +835,6 @@ S32 LLTextureCache::update(F32 max_time_ms)
 	mCompletedList.clear();
 	mListMutex.unlock();
 	
-	lockWorkers();
-	
-	for (handle_list_t::iterator iter1 = priorty_list.begin();
-		 iter1 != priorty_list.end(); ++iter1)
-	{
-		handle_t handle = *iter1;
-		handle_map_t::iterator iter2 = mWriters.find(handle);
-		if(iter2 != mWriters.end())
-		{
-			LLTextureCacheWorker* worker = iter2->second;
-			worker->setPriority(LLWorkerThread::PRIORITY_HIGH | worker->mPriority);
-		}
-	}
-
-	unlockWorkers(); 
-	
 	// call 'completed' with workers list unlocked (may call readComplete() or writeComplete()
 	for (responder_list_t::iterator iter1 = completed_list.begin();
 		 iter1 != completed_list.end(); ++iter1)
@@ -1323,6 +1268,7 @@ void LLTextureCache::updateEntryTimeStamp(S32 idx, Entry& entry)
 //update an existing entry, write to header file immediately.
 bool LLTextureCache::updateEntry(S32& idx, Entry& entry, S32 new_image_size, S32 new_data_size)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	S32 new_body_size = llmax(0, new_data_size - TEXTURE_CACHE_ENTRY_SIZE) ;
 	
 	if(new_image_size == entry.mImageSize && new_body_size == entry.mBodySize)
@@ -1872,6 +1818,7 @@ void LLTextureCache::purgeTextures(bool validate)
 // call lockWorkers() first!
 LLTextureCacheWorker* LLTextureCache::getReader(handle_t handle)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	LLTextureCacheWorker* res = NULL;
 	handle_map_t::iterator iter = mReaders.find(handle);
 	if (iter != mReaders.end())
@@ -1883,6 +1830,7 @@ LLTextureCacheWorker* LLTextureCache::getReader(handle_t handle)
 
 LLTextureCacheWorker* LLTextureCache::getWriter(handle_t handle)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	LLTextureCacheWorker* res = NULL;
 	handle_map_t::iterator iter = mWriters.find(handle);
 	if (iter != mWriters.end())
@@ -1898,6 +1846,7 @@ LLTextureCacheWorker* LLTextureCache::getWriter(handle_t handle)
 // Reads imagesize from the header, updates timestamp
 S32 LLTextureCache::getHeaderCacheEntry(const LLUUID& id, Entry& entry)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	LLMutexLock lock(&mHeaderMutex);	
 	S32 idx = openAndReadEntry(id, entry, false);
 	if (idx >= 0)
@@ -1910,6 +1859,7 @@ S32 LLTextureCache::getHeaderCacheEntry(const LLUUID& id, Entry& entry)
 // Writes imagesize to the header, updates timestamp
 S32 LLTextureCache::setHeaderCacheEntry(const LLUUID& id, Entry& entry, S32 imagesize, S32 datasize)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	mHeaderMutex.lock();
 	S32 idx = openAndReadEntry(id, entry, true); // read or create
 	mHeaderMutex.unlock();
@@ -1942,13 +1892,14 @@ S32 LLTextureCache::setHeaderCacheEntry(const LLUUID& id, Entry& entry, S32 imag
 
 // Calls from texture pipeline thread (i.e. LLTextureFetch)
 
-LLTextureCache::handle_t LLTextureCache::readFromCache(const std::string& filename, const LLUUID& id, U32 priority,
+LLTextureCache::handle_t LLTextureCache::readFromCache(const std::string& filename, const LLUUID& id,
 													   S32 offset, S32 size, ReadResponder* responder)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	// Note: checking to see if an entry exists can cause a stall,
 	//  so let the thread handle it
 	LLMutexLock lock(&mWorkersMutex);
-	LLTextureCacheWorker* worker = new LLTextureCacheLocalFileWorker(this, priority, filename, id,
+	LLTextureCacheWorker* worker = new LLTextureCacheLocalFileWorker(this, filename, id,
 																	 NULL, size, offset, 0,
 																	 responder);
 	handle_t handle = worker->read();
@@ -1956,13 +1907,14 @@ LLTextureCache::handle_t LLTextureCache::readFromCache(const std::string& filena
 	return handle;
 }
 
-LLTextureCache::handle_t LLTextureCache::readFromCache(const LLUUID& id, U32 priority,
+LLTextureCache::handle_t LLTextureCache::readFromCache(const LLUUID& id,
 													   S32 offset, S32 size, ReadResponder* responder)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	// Note: checking to see if an entry exists can cause a stall,
 	//  so let the thread handle it
 	LLMutexLock lock(&mWorkersMutex);
-	LLTextureCacheWorker* worker = new LLTextureCacheRemoteWorker(this, priority, id,
+	LLTextureCacheWorker* worker = new LLTextureCacheRemoteWorker(this, id,
 																  NULL, size, offset,
 																  0, NULL, 0, responder);
 	handle_t handle = worker->read();
@@ -1973,6 +1925,7 @@ LLTextureCache::handle_t LLTextureCache::readFromCache(const LLUUID& id, U32 pri
 
 bool LLTextureCache::readComplete(handle_t handle, bool abort)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	lockWorkers();
 	handle_map_t::iterator iter = mReaders.find(handle);
 	LLTextureCacheWorker* worker = NULL;
@@ -2000,7 +1953,7 @@ bool LLTextureCache::readComplete(handle_t handle, bool abort)
 	return (complete || abort);
 }
 
-LLTextureCache::handle_t LLTextureCache::writeToCache(const LLUUID& id, U32 priority,
+LLTextureCache::handle_t LLTextureCache::writeToCache(const LLUUID& id,
 													  U8* data, S32 datasize, S32 imagesize,
 													  LLPointer<LLImageRaw> rawimage, S32 discardlevel,
 													  WriteResponder* responder)
@@ -2018,7 +1971,7 @@ LLTextureCache::handle_t LLTextureCache::writeToCache(const LLUUID& id, U32 prio
 		mDoPurge = !mPurgeEntryList.empty();
 	}
 	LLMutexLock lock(&mWorkersMutex);
-	LLTextureCacheWorker* worker = new LLTextureCacheRemoteWorker(this, priority, id,
+	LLTextureCacheWorker* worker = new LLTextureCacheRemoteWorker(this, id,
 																  data, datasize, 0,
 																  imagesize, rawimage, discardlevel, responder);
 	handle_t handle = worker->write();
@@ -2086,6 +2039,7 @@ LLPointer<LLImageRaw> LLTextureCache::readFromFastCache(const LLUUID& id, S32& d
 //return the fast cache location
 bool LLTextureCache::writeToFastCache(LLUUID image_id, S32 id, LLPointer<LLImageRaw> raw, S32 discardlevel)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	//rescale image if needed
 	if (raw.isNull() || raw->isBufferInvalid() || !raw->getData())
 	{
diff --git a/indra/newview/lltexturecache.h b/indra/newview/lltexturecache.h
index e1c752b58e..f2a5978a7c 100644
--- a/indra/newview/lltexturecache.h
+++ b/indra/newview/lltexturecache.h
@@ -119,13 +119,13 @@ public:
 	void setReadOnly(BOOL read_only) ;
 	S64 initCache(ELLPath location, S64 maxsize, BOOL texture_cache_mismatch);
 
-	handle_t readFromCache(const std::string& local_filename, const LLUUID& id, U32 priority, S32 offset, S32 size,
+	handle_t readFromCache(const std::string& local_filename, const LLUUID& id, S32 offset, S32 size,
 						   ReadResponder* responder);
 
-	handle_t readFromCache(const LLUUID& id, U32 priority, S32 offset, S32 size,
+	handle_t readFromCache(const LLUUID& id, S32 offset, S32 size,
 						   ReadResponder* responder);
 	bool readComplete(handle_t handle, bool abort);
-	handle_t writeToCache(const LLUUID& id, U32 priority, U8* data, S32 datasize, S32 imagesize, LLPointer<LLImageRaw> rawimage, S32 discardlevel,
+	handle_t writeToCache(const LLUUID& id, U8* data, S32 datasize, S32 imagesize, LLPointer<LLImageRaw> rawimage, S32 discardlevel,
 						  WriteResponder* responder);
 	LLPointer<LLImageRaw> readFromFastCache(const LLUUID& id, S32& discardlevel);
 	bool writeComplete(handle_t handle, bool abort = false);
diff --git a/indra/newview/lltexturefetch.cpp b/indra/newview/lltexturefetch.cpp
index 35e4bb03ac..dc10e42446 100644
--- a/indra/newview/lltexturefetch.cpp
+++ b/indra/newview/lltexturefetch.cpp
@@ -62,8 +62,6 @@
 #include "llcorehttputil.h"
 #include "llhttpretrypolicy.h"
 
-bool LLTextureFetchDebugger::sDebuggerEnabled = false ;
-
 LLTrace::CountStatHandle<F64> LLTextureFetch::sCacheHit("texture_cache_hit");
 LLTrace::CountStatHandle<F64> LLTextureFetch::sCacheAttempt("texture_cache_attempt");
 LLTrace::EventStatHandle<LLUnit<F32, LLUnits::Percent> > LLTextureFetch::sCacheHitRate("texture_cache_hits");
@@ -213,35 +211,17 @@ const std::string sTesterName("TextureFetchTester");
 //
 // Worker State Machine
 //
-// (ASCII art needed)
-//
-//
-// Priority Scheme
-//
-// [PRIORITY_LOW, PRIORITY_NORMAL)   - for WAIT_HTTP_RESOURCE state
-//									   and other wait states
-// [PRIORITY_HIGH, PRIORITY_URGENT)  - External event delivered,
-//                                     rapidly transitioning through states,
-//                                     no waiting allowed
-//
-// By itself, the above work queue model would fail the concurrency
-// and liveness requirements of the interface.  A high priority
-// request could find itself on the head and stalled for external
-// reasons (see VWR-28996).  So a few additional constraints are
-// required to keep things running:
-// * Anything that can make forward progress must be kept at a
-//   higher priority than anything that can't.
-// * On completion of external events, the associated request
-//   needs to be elevated beyond the normal range to handle
-//   any data delivery and release any external resource.
-//
-// This effort is made to keep higher-priority entities moving
-// forward in their state machines at every possible step of
-// processing.  It's not entirely proven that this produces the
-// experiencial benefits promised.
+// "doWork" will be executed for a given worker on its respective
+// LLQueuedThread.  If doWork returns true, the worker is treated 
+// as completed.  If doWork returns false, the worker will be 
+// put on the back of the work queue at the start of the next iteration
+// of the mainloop.  If a worker is waiting on a resource, it should
+// return false as soon as possible and not block to avoid starving
+// other workers of cpu cycles.
 //
 
 
+
 //////////////////////////////////////////////////////////////////////////////
 
 // Tuning/Parameterization Constants
@@ -262,8 +242,8 @@ static const S32 HTTP_REQUESTS_RANGE_END_MAX = 20000000;
 //////////////////////////////////////////////////////////////////////////////
 namespace
 {
-    // The NoOpDeletor is used when passing certain objects (the LLTextureFetchWorker and
-    // the LLTextureFetchDebugger) in a smart pointer below for passage into 
+    // The NoOpDeletor is used when passing certain objects (the LLTextureFetchWorker)
+    // in a smart pointer below for passage into 
     // the LLCore::Http libararies. When the smart pointer is destroyed,  no 
     // action will be taken since we do not in these cases want the object to 
     // be destroyed at the end of the call.
@@ -301,7 +281,6 @@ class LLTextureFetchWorker : public LLWorkerClass, public LLCore::HttpHandler
 
 {
 	friend class LLTextureFetch;
-	friend class LLTextureFetchDebugger;
 	
 private:
 	class CacheReadResponder : public LLTextureCache::ReadResponder
@@ -386,14 +365,7 @@ private:
 		bool operator()(const LLTextureFetchWorker* lhs, const LLTextureFetchWorker* rhs) const
 		{
 			// greater priority is "less"
-			const F32 lpriority = lhs->mImagePriority;
-			const F32 rpriority = rhs->mImagePriority;
-			if (lpriority > rpriority) // higher priority
-				return true;
-			else if (lpriority < rpriority)
-				return false;
-			else
-				return lhs < rhs;
+            return lhs->mImagePriority > rhs->mImagePriority;
 		}
 	};
 	
@@ -484,6 +456,9 @@ private:
 	// Locks:  Mw
 	void resetFormattedData();
 	
+    // get the relative priority of this worker (should map to max virtual size)
+    F32 getImagePriority() const;
+
 	// Locks:  Mw
 	void setImagePriority(F32 priority);
 
@@ -500,9 +475,6 @@ private:
 	// Locks:  Mw
 	void setupPacketData();
 
-	// Locks:  Mw (ctor invokes without lock)
-	U32 calcWorkPriority();
-	
 	// Locks:  Mw
 	void removeFromCache();
 
@@ -573,16 +545,13 @@ private:
 	LLHost mHost;
 	std::string mUrl;
 	U8 mType;
-	F32 mImagePriority;
-	U32 mWorkPriority;
+	F32 mImagePriority; // should map to max virtual size
 	F32 mRequestedPriority;
 	S32 mDesiredDiscard;
 	S32 mSimRequestedDiscard;
 	S32 mRequestedDiscard;
     S32 mLoadedDiscard;
     S32 mDecodedDiscard;
-	S32 mFullWidth;
-	S32 mFullHeight;
 	LLFrameTimer mRequestedDeltaTimer;
 	LLFrameTimer mFetchDeltaTimer;
 	LLTimer mCacheReadTimer;
@@ -923,7 +892,6 @@ LLTextureFetchWorker::LLTextureFetchWorker(LLTextureFetch* fetcher,
 	  mHost(host),
 	  mUrl(url),
 	  mImagePriority(priority),
-	  mWorkPriority(0),
 	  mRequestedPriority(0.f),
 	  mDesiredDiscard(-1),
 	  mSimRequestedDiscard(-1),
@@ -970,17 +938,15 @@ LLTextureFetchWorker::LLTextureFetchWorker(LLTextureFetch* fetcher,
 	  mCacheReadCount(0U),
 	  mCacheWriteCount(0U),
 	  mResourceWaitCount(0U),
-	  mFetchRetryPolicy(10.0,3600.0,2.0,10)
+	  mFetchRetryPolicy(10.f,3600.f,2.f,10)
 {
 	mCanUseNET = mUrl.empty() ;
 	
-	calcWorkPriority();
 	mType = host.isOk() ? LLImageBase::TYPE_AVATAR_BAKE : LLImageBase::TYPE_NORMAL;
 // 	LL_INFOS(LOG_TXT) << "Create: " << mID << " mHost:" << host << " Discard=" << discard << LL_ENDL;
 	if (!mFetcher->mDebugPause)
 	{
-		U32 work_priority = mWorkPriority | LLWorkerThread::PRIORITY_HIGH;
-		addWork(0, work_priority );
+		addWork(0);
 	}
 	setDesiredDiscard(discard, size);
 }
@@ -1071,16 +1037,6 @@ void LLTextureFetchWorker::setupPacketData()
 }
 
 // Locks:  Mw (ctor invokes without lock)
-U32 LLTextureFetchWorker::calcWorkPriority()
-{
- 	//llassert_always(mImagePriority >= 0 && mImagePriority <= LLViewerFetchedTexture::maxDecodePriority());
-	static const F32 PRIORITY_SCALE = (F32)LLWorkerThread::PRIORITY_LOWBITS / LLViewerFetchedTexture::maxDecodePriority();
-
-	mWorkPriority = llmin((U32)LLWorkerThread::PRIORITY_LOWBITS, (U32)(mImagePriority * PRIORITY_SCALE));
-	return mWorkPriority;
-}
-
-// Locks:  Mw (ctor invokes without lock)
 void LLTextureFetchWorker::setDesiredDiscard(S32 discard, S32 size)
 {
 	bool prioritize = false;
@@ -1088,11 +1044,9 @@ void LLTextureFetchWorker::setDesiredDiscard(S32 discard, S32 size)
 	{
 		if (!haveWork())
 		{
-			calcWorkPriority();
 			if (!mFetcher->mDebugPause)
 			{
-				U32 work_priority = mWorkPriority | LLWorkerThread::PRIORITY_HIGH;
-				addWork(0, work_priority);
+				addWork(0);
 			}
 		}
 		else if (mDesiredDiscard < discard)
@@ -1111,23 +1065,13 @@ void LLTextureFetchWorker::setDesiredDiscard(S32 discard, S32 size)
 	if ((prioritize && mState == INIT) || mState == DONE)
 	{
 		setState(INIT);
-		U32 work_priority = mWorkPriority | LLWorkerThread::PRIORITY_HIGH;
-		setPriority(work_priority);
 	}
 }
 
 // Locks:  Mw
 void LLTextureFetchWorker::setImagePriority(F32 priority)
 {
-// 	llassert_always(priority >= 0 && priority <= LLViewerTexture::maxDecodePriority());
-	F32 delta = fabs(priority - mImagePriority);
-	if (delta > (mImagePriority * .05f) || mState == DONE)
-	{
-		mImagePriority = priority;
-		calcWorkPriority();
-		U32 work_priority = mWorkPriority | (getPriority() & LLWorkerThread::PRIORITY_HIGHBITS);
-		setPriority(work_priority);
-	}
+	mImagePriority = priority; //should map to max virtual size, abort if zero
 }
 
 // Locks:  Mw
@@ -1147,6 +1091,11 @@ void LLTextureFetchWorker::resetFormattedData()
 	mHaveAllData = FALSE;
 }
 
+F32 LLTextureFetchWorker::getImagePriority() const
+{
+    return mImagePriority;
+}
+
 // Threads:  Tmain
 void LLTextureFetchWorker::startWork(S32 param)
 {
@@ -1156,7 +1105,7 @@ void LLTextureFetchWorker::startWork(S32 param)
 // Threads:  Ttf
 bool LLTextureFetchWorker::doWork(S32 param)
 {
-    LL_PROFILE_ZONE_SCOPED;
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_THREAD;
 	if (gNonInteractive)
 	{
 		return true;
@@ -1171,20 +1120,23 @@ bool LLTextureFetchWorker::doWork(S32 param)
 	{
 		if (mState < DECODE_IMAGE)
 		{
+            LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("tfwdw - state < decode");
 			return true; // abort
 		}
 	}
 
-	if(mImagePriority < F_ALMOST_ZERO)
+	if (mImagePriority < F_ALMOST_ZERO)
 	{
 		if (mState == INIT || mState == LOAD_FROM_NETWORK || mState == LOAD_FROM_SIMULATOR)
 		{
+            LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("tfwdw - priority < 0");
 			LL_DEBUGS(LOG_TXT) << mID << " abort: mImagePriority < F_ALMOST_ZERO" << LL_ENDL;
 			return true; // abort
 		}
 	}
 	if(mState > CACHE_POST && !mCanUseNET && !mCanUseHTTP)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("tfwdw - state > cache_post");
 		//nowhere to get data, abort.
 		LL_WARNS(LOG_TXT) << mID << " abort, nowhere to get data" << LL_ENDL;
 		return true ;
@@ -1206,6 +1158,7 @@ bool LLTextureFetchWorker::doWork(S32 param)
 
 	if (mState == INIT)
 	{		
+        LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("tfwdw - INIT");
 		mStateTimer.reset();
 		mFetchTimer.reset();
 		for(auto i : LOGGED_STATES) 
@@ -1247,15 +1200,16 @@ bool LLTextureFetchWorker::doWork(S32 param)
 
 	if (mState == LOAD_FROM_TEXTURE_CACHE)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("tfwdw - LOAD_FROM_TEXTURE_CACHE");
 		if (mCacheReadHandle == LLTextureCache::nullHandle())
 		{
-			U32 cache_priority = mWorkPriority;
 			S32 offset = mFormattedImage.notNull() ? mFormattedImage->getDataSize() : 0;
 			S32 size = mDesiredSize - offset;
 			if (size <= 0)
 			{
 				setState(CACHE_POST);
-				return false;
+                return doWork(param);
+                // return false;
 			}
 			mFileSize = 0;
 			mLoaded = FALSE;			
@@ -1264,35 +1218,28 @@ bool LLTextureFetchWorker::doWork(S32 param)
 
 			if (mUrl.compare(0, 7, "file://") == 0)
 			{
-				setPriority(LLWorkerThread::PRIORITY_LOW | mWorkPriority); // Set priority first since Responder may change it
-
 				// read file from local disk
 				++mCacheReadCount;
 				std::string filename = mUrl.substr(7, std::string::npos);
 				CacheReadResponder* responder = new CacheReadResponder(mFetcher, mID, mFormattedImage);
 				mCacheReadTimer.reset();  
-				mCacheReadHandle = mFetcher->mTextureCache->readFromCache(filename, mID, cache_priority,
-																		  offset, size, responder);
+				mCacheReadHandle = mFetcher->mTextureCache->readFromCache(filename, mID, offset, size, responder);
               
 			}
 			else if ((mUrl.empty() || mFTType==FTT_SERVER_BAKE) && mFetcher->canLoadFromCache())
 			{
-				setPriority(LLWorkerThread::PRIORITY_LOW | mWorkPriority); // Set priority first since Responder may change it
-
 				++mCacheReadCount;
 				CacheReadResponder* responder = new CacheReadResponder(mFetcher, mID, mFormattedImage);
 				mCacheReadTimer.reset();
-				mCacheReadHandle = mFetcher->mTextureCache->readFromCache(mID, cache_priority,
+				mCacheReadHandle = mFetcher->mTextureCache->readFromCache(mID,
 																		  offset, size, responder);;
 			}
 			else if(!mUrl.empty() && mCanUseHTTP)
 			{
-				setPriority(LLWorkerThread::PRIORITY_HIGH | mWorkPriority);
 				setState(WAIT_HTTP_RESOURCE);
 			}
 			else
 			{
-				setPriority(LLWorkerThread::PRIORITY_HIGH | mWorkPriority);
 				setState(LOAD_FROM_NETWORK);
 			}
 		}
@@ -1325,6 +1272,7 @@ bool LLTextureFetchWorker::doWork(S32 param)
 
 	if (mState == CACHE_POST)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("tfwdw - CACHE_POST");
 		mCachedSize = mFormattedImage.notNull() ? mFormattedImage->getDataSize() : 0;
 		// Successfully loaded
 		if ((mCachedSize >= mDesiredSize) || mHaveAllData)
@@ -1366,6 +1314,7 @@ bool LLTextureFetchWorker::doWork(S32 param)
 
 	if (mState == LOAD_FROM_NETWORK)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("tfwdw - LOAD_FROM_NETWORK");
 		// Check for retries to previous server failures.
 		F32 wait_seconds;
 		if (mFetchRetryPolicy.shouldRetry(wait_seconds))
@@ -1399,7 +1348,7 @@ bool LLTextureFetchWorker::doWork(S32 param)
 				{
 					if (mFTType != FTT_DEFAULT)
 					{
-						LL_WARNS(LOG_TXT) << "trying to seek a non-default texture on the sim. Bad!" << LL_ENDL;
+                        LL_WARNS(LOG_TXT) << "Trying to fetch a texture of non-default type by UUID. This probably won't work!" << LL_ENDL;
 					}
 					setUrl(http_url + "/?texture_id=" + mID.asString().c_str());
 					LL_DEBUGS(LOG_TXT) << "Texture URL: " << mUrl << LL_ENDL;
@@ -1427,7 +1376,6 @@ bool LLTextureFetchWorker::doWork(S32 param)
 		if (mCanUseHTTP && !mUrl.empty())
 		{
 			setState(WAIT_HTTP_RESOURCE);
-			setPriority(LLWorkerThread::PRIORITY_HIGH | mWorkPriority);
 			if(mWriteToCacheState != NOT_WRITE)
 			{
 				mWriteToCacheState = CAN_WRITE ;
@@ -1444,25 +1392,19 @@ bool LLTextureFetchWorker::doWork(S32 param)
 			mSentRequest = QUEUED;
 			mFetcher->addToNetworkQueue(this);
 			recordTextureStart(false);
-			setPriority(LLWorkerThread::PRIORITY_LOW | mWorkPriority);
-			
 			return false;
 		}
 		else
 		{
 			// Shouldn't need to do anything here
-			//llassert_always(mFetcher->mNetworkQueue.find(mID) != mFetcher->mNetworkQueue.end());
-			// Make certain this is in the network queue
-			//mFetcher->addToNetworkQueue(this);
-			//recordTextureStart(false);
-			//setPriority(LLWorkerThread::PRIORITY_LOW | mWorkPriority);
-
+			//llassert(mFetcher->mNetworkQueue.find(mID) != mFetcher->mNetworkQueue.end());
 			return false;
 		}
 	}
 	
 	if (mState == LOAD_FROM_SIMULATOR)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("tfwdw - LOAD_FROM_SIMULATOR");
 		if (mFormattedImage.isNull())
 		{
 			mFormattedImage = new LLImageJ2C;
@@ -1492,7 +1434,7 @@ bool LLTextureFetchWorker::doWork(S32 param)
 				LL_WARNS(LOG_TXT) << mID << " processSimulatorPackets() failed to load buffer" << LL_ENDL;
 				return true; // failed
 			}
-			setPriority(LLWorkerThread::PRIORITY_HIGH | mWorkPriority);
+
 			if (mLoadedDiscard < 0)
 			{
 				LL_WARNS(LOG_TXT) << mID << " mLoadedDiscard is " << mLoadedDiscard
@@ -1506,7 +1448,6 @@ bool LLTextureFetchWorker::doWork(S32 param)
 		else
 		{
 			mFetcher->addToNetworkQueue(this); // failsafe
-			setPriority(LLWorkerThread::PRIORITY_LOW | mWorkPriority);
 			recordTextureStart(false);
 		}
 		return false;
@@ -1514,6 +1455,7 @@ bool LLTextureFetchWorker::doWork(S32 param)
 	
 	if (mState == WAIT_HTTP_RESOURCE)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("tfwdw - WAIT_HTTP_RESOURCE");
 		// NOTE:
 		// control the number of the http requests issued for:
 		// 1, not openning too many file descriptors at the same time;
@@ -1524,7 +1466,6 @@ bool LLTextureFetchWorker::doWork(S32 param)
 		if (mFetcher->getHttpWaitersCount() || ! acquireHttpSemaphore())
 		{
 			setState(WAIT_HTTP_RESOURCE2);
-			setPriority(LLWorkerThread::PRIORITY_LOW | mWorkPriority);
 			mFetcher->addHttpWaiter(this->mID);
 			++mResourceWaitCount;
 			return false;
@@ -1538,12 +1479,14 @@ bool LLTextureFetchWorker::doWork(S32 param)
 
 	if (mState == WAIT_HTTP_RESOURCE2)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("tfwdw - WAIT_HTTP_RESOURCE2");
 		// Just idle it if we make it to the head...
 		return false;
 	}
 	
 	if (mState == SEND_HTTP_REQ)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("tfwdw - SEND_HTTP_REQ");
 		// Also used in llmeshrepository
 		static LLCachedControl<bool> disable_range_req(gSavedSettings, "HttpRangeRequestsDisable", false);
 		
@@ -1566,7 +1509,6 @@ bool LLTextureFetchWorker::doWork(S32 param)
 				{
 					// We already have all the data, just decode it
 					mLoadedDiscard = mFormattedImage->getDiscardLevel();
-					setPriority(LLWorkerThread::PRIORITY_HIGH | mWorkPriority);
 					if (mLoadedDiscard < 0)
 					{
 						LL_WARNS(LOG_TXT) << mID << " mLoadedDiscard is " << mLoadedDiscard
@@ -1574,7 +1516,8 @@ bool LLTextureFetchWorker::doWork(S32 param)
 					}
 					setState(DECODE_IMAGE);
 					releaseHttpSemaphore();
-					return false;
+					//return false;
+                    return doWork(param);
 				}
 				else
 				{
@@ -1635,7 +1578,6 @@ bool LLTextureFetchWorker::doWork(S32 param)
 			// by people with questionable ISPs or networking gear that
 			// doesn't handle these well.
 			mHttpHandle = mFetcher->mHttpRequest->requestGet(mHttpPolicyClass,
-															 mWorkPriority,
 															 mUrl,
 															 options,
 															 mFetcher->mHttpHeaders,
@@ -1644,7 +1586,6 @@ bool LLTextureFetchWorker::doWork(S32 param)
 		else
 		{
 			mHttpHandle = mFetcher->mHttpRequest->requestGetByteRange(mHttpPolicyClass,
-																	  mWorkPriority,
 																	  mUrl,
 																	  mRequestedOffset,
 																	  (mRequestedOffset + mRequestedSize) > HTTP_REQUESTS_RANGE_END_MAX
@@ -1669,7 +1610,6 @@ bool LLTextureFetchWorker::doWork(S32 param)
 		mHttpActive = true;
 		mFetcher->addToHTTPQueue(mID);
 		recordTextureStart(true);
-		setPriority(LLWorkerThread::PRIORITY_LOW | mWorkPriority);
 		setState(WAIT_HTTP_REQ);	
 		
 		// fall through
@@ -1677,6 +1617,7 @@ bool LLTextureFetchWorker::doWork(S32 param)
 	
 	if (mState == WAIT_HTTP_REQ)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("tfwdw - WAIT_HTTP_REQ");
 		// *NOTE:  As stated above, all transitions out of this state should
 		// call releaseHttpSemaphore().
 		if (mLoaded)
@@ -1708,9 +1649,9 @@ bool LLTextureFetchWorker::doWork(S32 param)
 						setState(INIT);
 						mCanUseHTTP = false;
 						mUrl.clear();
-						setPriority(LLWorkerThread::PRIORITY_HIGH | mWorkPriority);
 						releaseHttpSemaphore();
-						return false;
+						//return false;
+                        return doWork(param);
 					}
 				}
 				else if (http_service_unavail == mGetStatus)
@@ -1730,7 +1671,7 @@ bool LLTextureFetchWorker::doWork(S32 param)
 									  << LL_ENDL;
 				}
 
-				if (mFTType != FTT_SERVER_BAKE)
+                if (mFTType != FTT_SERVER_BAKE && mFTType != FTT_MAP_TILE)
 				{
 					mUrl.clear();
 				}
@@ -1738,7 +1679,6 @@ bool LLTextureFetchWorker::doWork(S32 param)
 				{
 					// Use available data
 					mLoadedDiscard = mFormattedImage->getDiscardLevel();
-					setPriority(LLWorkerThread::PRIORITY_HIGH | mWorkPriority);
 					if (mLoadedDiscard < 0)
 					{
 						LL_WARNS(LOG_TXT) << mID << " mLoadedDiscard is " << mLoadedDiscard
@@ -1746,7 +1686,8 @@ bool LLTextureFetchWorker::doWork(S32 param)
 					}
 					setState(DECODE_IMAGE);
 					releaseHttpSemaphore();
-					return false; 
+					//return false; 
+                    return doWork(param);
 				}
 
 				// Fail harder
@@ -1863,9 +1804,9 @@ bool LLTextureFetchWorker::doWork(S32 param)
 			{
 				mWriteToCacheState = SHOULD_WRITE ;
 			}
-			setPriority(LLWorkerThread::PRIORITY_HIGH | mWorkPriority);
 			releaseHttpSemaphore();
-			return false;
+			//return false;
+            return doWork(param);
 		}
 		else
 		{
@@ -1875,17 +1816,16 @@ bool LLTextureFetchWorker::doWork(S32 param)
 			// an enormous amount of time to load textures.  We'll revisit the
 			// various possible timeout components (total request time, connection
 			// time, I/O time, with and without retries, etc.) in the future.
-
-			setPriority(LLWorkerThread::PRIORITY_LOW | mWorkPriority);
+			
 			return false;
 		}
 	}
 	
 	if (mState == DECODE_IMAGE)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("tfwdw - DECODE_IMAGE");
 		static LLCachedControl<bool> textures_decode_disabled(gSavedSettings, "TextureDecodeDisabled", false);
 
-		setPriority(LLWorkerThread::PRIORITY_LOW | mWorkPriority); // Set priority first since Responder may change it
 		if (textures_decode_disabled)
 		{
 			// for debug use, don't decode
@@ -1924,25 +1864,20 @@ bool LLTextureFetchWorker::doWork(S32 param)
 		mAuxImage = NULL;
 		llassert_always(mFormattedImage.notNull());
 		S32 discard = mHaveAllData ? 0 : mLoadedDiscard;
-		U32 image_priority = LLWorkerThread::PRIORITY_NORMAL | mWorkPriority;
 		mDecoded  = FALSE;
 		setState(DECODE_IMAGE_UPDATE);
 		LL_DEBUGS(LOG_TXT) << mID << ": Decoding. Bytes: " << mFormattedImage->getDataSize() << " Discard: " << discard
 						   << " All Data: " << mHaveAllData << LL_ENDL;
-		mDecodeHandle = mFetcher->mImageDecodeThread->decodeImage(mFormattedImage, image_priority, discard, mNeedsAux,
+		mDecodeHandle = LLAppViewer::getImageDecodeThread()->decodeImage(mFormattedImage, discard, mNeedsAux,
 																  new DecodeResponder(mFetcher, mID, this));
 		// fall though
 	}
 	
 	if (mState == DECODE_IMAGE_UPDATE)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("tfwdw - DECODE_IMAGE_UPDATE");
 		if (mDecoded)
 		{
-			if(mFetcher->getFetchDebugger() && !mInLocalCache)
-			{
-				mFetcher->getFetchDebugger()->addHistoryEntry(this);
-			}
-
             mDecodeTime = mDecodeTimer.getElapsedTimeF32();
 
 			if (mDecodedDiscard < 0)
@@ -1954,9 +1889,9 @@ bool LLTextureFetchWorker::doWork(S32 param)
 					llassert_always(mDecodeHandle == 0);
 					mFormattedImage = NULL;
 					++mRetryAttempt;
-					setPriority(LLWorkerThread::PRIORITY_HIGH | mWorkPriority);
 					setState(INIT);
-					return false;
+					//return false;
+                    return doWork(param);
 				}
 				else
 				{
@@ -1969,7 +1904,6 @@ bool LLTextureFetchWorker::doWork(S32 param)
 				llassert_always(mRawImage.notNull());
 				LL_DEBUGS(LOG_TXT) << mID << ": Decoded. Discard: " << mDecodedDiscard
 								   << " Raw Image: " << llformat("%dx%d",mRawImage->getWidth(),mRawImage->getHeight()) << LL_ENDL;
-				setPriority(LLWorkerThread::PRIORITY_HIGH | mWorkPriority);
 				setState(WRITE_TO_CACHE);
 			}
 			// fall through
@@ -1982,12 +1916,14 @@ bool LLTextureFetchWorker::doWork(S32 param)
 
 	if (mState == WRITE_TO_CACHE)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("tfwdw - WRITE_TO_CACHE");
 		if (mWriteToCacheState != SHOULD_WRITE || mFormattedImage.isNull())
 		{
 			// If we're in a local cache or we didn't actually receive any new data,
 			// or we failed to load anything, skip
 			setState(DONE);
-			return false;
+			//return false;
+            return doWork(param);
 		}
 		S32 datasize = mFormattedImage->getDataSize();
 		if(mFileSize < datasize)//This could happen when http fetching and sim fetching mixed.
@@ -2002,8 +1938,6 @@ bool LLTextureFetchWorker::doWork(S32 param)
 			}
 		}
 		llassert_always(datasize);
-		setPriority(LLWorkerThread::PRIORITY_LOW | mWorkPriority); // Set priority first since Responder may change it
-		U32 cache_priority = mWorkPriority;
 		mWritten = FALSE;
 		setState(WAIT_ON_WRITE);
 		++mCacheWriteCount;
@@ -2014,7 +1948,7 @@ bool LLTextureFetchWorker::doWork(S32 param)
         // So make sure users of getRequestFinished() does not attempt to modify image while
         // fetcher is working
 		mCacheWriteTimer.reset();
-		mCacheWriteHandle = mFetcher->mTextureCache->writeToCache(mID, cache_priority,
+		mCacheWriteHandle = mFetcher->mTextureCache->writeToCache(mID,
 																  mFormattedImage->getData(), datasize,
 																  mFileSize, mRawImage, mDecodedDiscard, responder);
 		// fall through
@@ -2022,6 +1956,7 @@ bool LLTextureFetchWorker::doWork(S32 param)
 	
 	if (mState == WAIT_ON_WRITE)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("tfwdw - WAIT_ON_WRITE");
 		if (writeToCacheComplete())
 		{
 			mCacheWriteTime = mCacheWriteTimer.getElapsedTimeF32();
@@ -2043,6 +1978,7 @@ bool LLTextureFetchWorker::doWork(S32 param)
 
 	if (mState == DONE)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_THREAD("tfwdw - DONE");
 		if (mDecodedDiscard >= 0 && mDesiredDiscard < mDecodedDiscard)
 		{
 			// More data was requested, return to INIT
@@ -2050,12 +1986,11 @@ bool LLTextureFetchWorker::doWork(S32 param)
 			LL_DEBUGS(LOG_TXT) << mID << " more data requested, returning to INIT: " 
 							   << " mDecodedDiscard " << mDecodedDiscard << ">= 0 && mDesiredDiscard " << mDesiredDiscard
 							   << "<" << " mDecodedDiscard " << mDecodedDiscard << LL_ENDL;
-			setPriority(LLWorkerThread::PRIORITY_HIGH | mWorkPriority);
-			return false;
+			// return false;
+            return doWork(param);
 		}
 		else
 		{
-			setPriority(LLWorkerThread::PRIORITY_LOW | mWorkPriority);
             mFetchTime = mFetchTimer.getElapsedTimeF32();
 			return true;
 		}
@@ -2068,6 +2003,7 @@ bool LLTextureFetchWorker::doWork(S32 param)
 // virtual
 void LLTextureFetchWorker::onCompleted(LLCore::HttpHandle handle, LLCore::HttpResponse * response)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	static LLCachedControl<bool> log_to_viewer_log(gSavedSettings, "LogTextureDownloadsToViewerLog", false);
 	static LLCachedControl<bool> log_to_sim(gSavedSettings, "LogTextureDownloadsToSimulator", false);
 	static LLCachedControl<bool> log_texture_traffic(gSavedSettings, "LogTextureNetworkTraffic", false) ;
@@ -2177,9 +2113,10 @@ void LLTextureFetchWorker::onCompleted(LLCore::HttpHandle handle, LLCore::HttpRe
 // Threads:  Tmain
 void LLTextureFetchWorker::endWork(S32 param, bool aborted)
 {
+	LL_PROFILE_ZONE_SCOPED;
 	if (mDecodeHandle != 0)
 	{
-		mFetcher->mImageDecodeThread->abortRequest(mDecodeHandle, false);
+		// LL::ThreadPool has no operation to cancel a particular work item
 		mDecodeHandle = 0;
 	}
 	mFormattedImage = NULL;
@@ -2192,6 +2129,7 @@ void LLTextureFetchWorker::endWork(S32 param, bool aborted)
 // virtual
 void LLTextureFetchWorker::finishWork(S32 param, bool completed)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	// The following are required in case the work was aborted
 	if (mCacheReadHandle != LLTextureCache::nullHandle())
 	{
@@ -2445,7 +2383,6 @@ S32 LLTextureFetchWorker::callbackHttpGet(LLCore::HttpResponse * response,
 	}
 	
 	mLoaded = TRUE;
-	setPriority(LLWorkerThread::PRIORITY_HIGH | mWorkPriority);
 
 	if (LLViewerStatsRecorder::instanceExists())
 	{
@@ -2461,6 +2398,7 @@ S32 LLTextureFetchWorker::callbackHttpGet(LLCore::HttpResponse * response,
 void LLTextureFetchWorker::callbackCacheRead(bool success, LLImageFormatted* image,
 											 S32 imagesize, BOOL islocal)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	LLMutexLock lock(&mWorkMutex);										// +Mw
 	if (mState != LOAD_FROM_TEXTURE_CACHE)
 	{
@@ -2480,7 +2418,6 @@ void LLTextureFetchWorker::callbackCacheRead(bool success, LLImageFormatted* ima
 		}
 	}
 	mLoaded = TRUE;
-	setPriority(LLWorkerThread::PRIORITY_HIGH | mWorkPriority);
 }																		// -Mw
 
 // Threads:  Ttc
@@ -2493,7 +2430,6 @@ void LLTextureFetchWorker::callbackCacheWrite(bool success)
 		return;
 	}
 	mWritten = TRUE;
-	setPriority(LLWorkerThread::PRIORITY_HIGH | mWorkPriority);
 }																		// -Mw
 
 //////////////////////////////////////////////////////////////////////////////
@@ -2532,7 +2468,6 @@ void LLTextureFetchWorker::callbackDecoded(bool success, LLImageRaw* raw, LLImag
 	}
 	mDecoded = TRUE;
 // 	LL_INFOS(LOG_TXT) << mID << " : DECODE COMPLETE " << LL_ENDL;
-	setPriority(LLWorkerThread::PRIORITY_HIGH | mWorkPriority);
 }																		// -Mw
 
 //////////////////////////////////////////////////////////////////////////////
@@ -2595,7 +2530,17 @@ void LLTextureFetchWorker::recordTextureDone(bool is_http, F64 byte_count)
 //////////////////////////////////////////////////////////////////////////////
 // public
 
-LLTextureFetch::LLTextureFetch(LLTextureCache* cache, LLImageDecodeThread* imagedecodethread, bool threaded, bool qa_mode)
+std::string LLTextureFetch::getStateString(S32 state)
+{
+    if (state < 0 || state > sizeof(e_state_name) / sizeof(char*))
+    {
+        return llformat("%d", state);
+    }
+
+    return e_state_name[state];
+}
+
+LLTextureFetch::LLTextureFetch(LLTextureCache* cache, bool threaded, bool qa_mode)
 	: LLWorkerThread("TextureFetch", threaded, true),
 	  mDebugCount(0),
 	  mDebugPause(FALSE),
@@ -2604,7 +2549,6 @@ LLTextureFetch::LLTextureFetch(LLTextureCache* cache, LLImageDecodeThread* image
 	  mQueueMutex(),
 	  mNetworkQueueMutex(),
 	  mTextureCache(cache),
-	  mImageDecodeThread(imagedecodethread),
 	  mTextureBandwidth(0),
 	  mHTTPTextureBits(0),
 	  mTotalHTTPRequests(0),
@@ -2619,10 +2563,8 @@ LLTextureFetch::LLTextureFetch(LLTextureCache* cache, LLImageDecodeThread* image
 	  mTotalCacheReadCount(0U),
 	  mTotalCacheWriteCount(0U),
 	  mTotalResourceWaitCount(0U),
-	  mFetchDebugger(NULL),
 	  mFetchSource(LLTextureFetch::FROM_ALL),
 	  mOriginFetchSource(LLTextureFetch::FROM_ALL),
-	  mFetcherLocked(FALSE),
 	  mTextureInfoMainThread(false)
 {
 	mMaxBandwidth = gSavedSettings.getF32("ThrottleBandwidthKBPS");
@@ -2643,21 +2585,6 @@ LLTextureFetch::LLTextureFetch(LLTextureCache* cache, LLImageDecodeThread* image
 	mHttpLowWater = HTTP_NONPIPE_REQUESTS_LOW_WATER;
 	mHttpSemaphore = 0;
 
-	// Conditionally construct debugger object after 'this' is
-	// fully initialized.
-	LLTextureFetchDebugger::sDebuggerEnabled = gSavedSettings.getBOOL("TextureFetchDebuggerEnabled");
-	if(LLTextureFetchDebugger::isEnabled())
-	{
-		mFetchDebugger = new LLTextureFetchDebugger(this, cache, imagedecodethread) ;
-		mFetchSource = (e_tex_source)gSavedSettings.getS32("TextureFetchSource");
-		if(mFetchSource < 0 && mFetchSource >= INVALID_SOURCE)
-		{
-			mFetchSource = LLTextureFetch::FROM_ALL;
-			gSavedSettings.setS32("TextureFetchSource", 0);
-		}
-		mOriginFetchSource = mFetchSource;
-	}
-
 	// If that test log has ben requested but not yet created, create it
 	if (LLMetricPerformanceTesterBasic::isMetricLogRequested(sTesterName) && !LLMetricPerformanceTesterBasic::getTester(sTesterName))
 	{
@@ -2686,19 +2613,13 @@ LLTextureFetch::~LLTextureFetch()
 	delete mHttpRequest;
 	mHttpRequest = NULL;
 
-	delete mFetchDebugger;
-	mFetchDebugger = NULL;
-	
 	// ~LLQueuedThread() called here
 }
 
 bool LLTextureFetch::createRequest(FTType f_type, const std::string& url, const LLUUID& id, const LLHost& host, F32 priority,
 								   S32 w, S32 h, S32 c, S32 desired_discard, bool needs_aux, bool can_use_http)
 {
-	if(mFetcherLocked)
-	{
-		return false;
-	}
+    LL_PROFILE_ZONE_SCOPED;
 	if (mDebugPause)
 	{
 		return false;
@@ -2773,6 +2694,11 @@ bool LLTextureFetch::createRequest(FTType f_type, const std::string& url, const
 			return false; // need to wait for previous aborted request to complete
 		}
 		worker->lockWorkMutex();										// +Mw
+        if (worker->mState == LLTextureFetchWorker::DONE && worker->mDesiredSize == llmax(desired_size, TEXTURE_CACHE_ENTRY_SIZE) && worker->mDesiredDiscard == desired_discard) {
+			worker->unlockWorkMutex();									// -Mw
+
+            return false; // similar request has failed or is in a transitional state
+        }
 		worker->mActiveCount++;
 		worker->mNeedsAux = needs_aux;
 		worker->setImagePriority(priority);
@@ -2786,7 +2712,7 @@ bool LLTextureFetch::createRequest(FTType f_type, const std::string& url, const
 			worker->setState(LLTextureFetchWorker::INIT);
 			worker->unlockWorkMutex();									// -Mw
 
-			worker->addWork(0, LLWorkerThread::PRIORITY_HIGH | worker->mWorkPriority);
+			worker->addWork(0);
 		}
 		else
 		{
@@ -2818,6 +2744,7 @@ bool LLTextureFetch::createRequest(FTType f_type, const std::string& url, const
 // protected
 void LLTextureFetch::addToNetworkQueue(LLTextureFetchWorker* worker)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	lockQueue();														// +Mfq
 	bool in_request_map = (mRequestMap.find(worker->mID) != mRequestMap.end()) ;
 	unlockQueue();														// -Mfq
@@ -2839,6 +2766,7 @@ void LLTextureFetch::addToNetworkQueue(LLTextureFetchWorker* worker)
 // Threads:  T*
 void LLTextureFetch::removeFromNetworkQueue(LLTextureFetchWorker* worker, bool cancel)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	LLMutexLock lock(&mNetworkQueueMutex);								// +Mfnq
 	size_t erased = mNetworkQueue.erase(worker->mID);
 	if (cancel && erased > 0)
@@ -2852,6 +2780,7 @@ void LLTextureFetch::removeFromNetworkQueue(LLTextureFetchWorker* worker, bool c
 // protected
 void LLTextureFetch::addToHTTPQueue(const LLUUID& id)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	LLMutexLock lock(&mNetworkQueueMutex);								// +Mfnq
 	mHTTPTextureQueue.insert(id);
 	mTotalHTTPRequests++;
@@ -2860,6 +2789,7 @@ void LLTextureFetch::addToHTTPQueue(const LLUUID& id)
 // Threads:  T*
 void LLTextureFetch::removeFromHTTPQueue(const LLUUID& id, S32Bytes received_size)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	LLMutexLock lock(&mNetworkQueueMutex);								// +Mfnq
 	mHTTPTextureQueue.erase(id);
 	mHTTPTextureBits += received_size; // Approximate - does not include header bits	
@@ -2872,6 +2802,7 @@ void LLTextureFetch::removeFromHTTPQueue(const LLUUID& id, S32Bytes received_siz
 // Threads:  T*
 void LLTextureFetch::deleteRequest(const LLUUID& id, bool cancel)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	lockQueue();														// +Mfq
 	LLTextureFetchWorker* worker = getWorkerAfterLock(id);
 	if (worker)
@@ -2898,6 +2829,7 @@ void LLTextureFetch::deleteRequest(const LLUUID& id, bool cancel)
 // Threads:  T*
 void LLTextureFetch::removeRequest(LLTextureFetchWorker* worker, bool cancel)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	if(!worker)
 	{
 		return;
@@ -2967,6 +2899,7 @@ U32 LLTextureFetch::getTotalNumHTTPRequests()
 // Locks:  Mfq
 LLTextureFetchWorker* LLTextureFetch::getWorkerAfterLock(const LLUUID& id)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	LLTextureFetchWorker* res = NULL;
 	map_t::iterator iter = mRequestMap.find(id);
 	if (iter != mRequestMap.end())
@@ -2990,6 +2923,7 @@ bool LLTextureFetch::getRequestFinished(const LLUUID& id, S32& discard_level,
 										LLPointer<LLImageRaw>& raw, LLPointer<LLImageRaw>& aux,
 										LLCore::HttpStatus& last_http_get_status)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	bool res = false;
 	LLTextureFetchWorker* worker = getWorker(id);
 	if (worker)
@@ -3004,7 +2938,7 @@ bool LLTextureFetch::getRequestFinished(const LLUUID& id, S32& discard_level,
 			if (!mDebugPause)
 			{
 // 				LL_WARNS(LOG_TXT) << "Adding work for inactive worker: " << id << LL_ENDL;
-				worker->addWork(0, LLWorkerThread::PRIORITY_HIGH | worker->mWorkPriority);
+				worker->addWork(0);
 			}
 		}
 		else if (worker->checkWork())
@@ -3080,16 +3014,19 @@ bool LLTextureFetch::getRequestFinished(const LLUUID& id, S32& discard_level,
 // Threads:  T*
 bool LLTextureFetch::updateRequestPriority(const LLUUID& id, F32 priority)
 {
-	bool res = false;
-	LLTextureFetchWorker* worker = getWorker(id);
-	if (worker)
-	{
-		worker->lockWorkMutex();										// +Mw
-		worker->setImagePriority(priority);
-		worker->unlockWorkMutex();										// -Mw
-		res = true;
-	}
-	return res;
+    LL_PROFILE_ZONE_SCOPED;
+    mRequestQueue.tryPost([=]()
+        {
+            LLTextureFetchWorker* worker = getWorker(id);
+            if (worker)
+            {
+                worker->lockWorkMutex();										// +Mw
+                worker->setImagePriority(priority);
+                worker->unlockWorkMutex();										// -Mw
+            }
+        });
+	
+	return true;
 }
 
 // Replicates and expands upon the base class's
@@ -3106,6 +3043,7 @@ bool LLTextureFetch::updateRequestPriority(const LLUUID& id, F32 priority)
 //virtual
 S32 LLTextureFetch::getPending()
 {
+    LL_PROFILE_ZONE_SCOPED;
 	S32 res;
 	lockData();															// +Ct
     {
@@ -3139,7 +3077,7 @@ bool LLTextureFetch::runCondition()
 	}																	// -Mfq
 	
 	return ! (have_no_commands
-			  && (mRequestQueue.empty() && mIdleThread));		// From base class
+			  && (mRequestQueue.size() == 0 && mIdleThread));		// From base class
 }
 
 //////////////////////////////////////////////////////////////////////////////
@@ -3147,6 +3085,7 @@ bool LLTextureFetch::runCondition()
 // Threads:  Ttf
 void LLTextureFetch::commonUpdate()
 {
+    LL_PROFILE_ZONE_SCOPED;
 	// Update low/high water levels based on pipelining.  We pick
 	// up setting eventually, so the semaphore/request level can
 	// fall outside the [0..HIGH_WATER] range.  Expect that.
@@ -3183,6 +3122,7 @@ void LLTextureFetch::commonUpdate()
 //virtual
 S32 LLTextureFetch::update(F32 max_time_ms)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	static LLCachedControl<F32> band_width(gSavedSettings,"ThrottleBandwidthKBPS", 3000.0);
 
 	{
@@ -3213,11 +3153,6 @@ S32 LLTextureFetch::update(F32 max_time_ms)
 		commonUpdate();
 	}
 
-	if (mFetchDebugger)
-	{
-		mFetchDebugger->tryToStopDebug(); //check if need to stop debugger.
-	}
-
 	return res;
 }
 
@@ -3233,18 +3168,6 @@ void LLTextureFetch::shutDownTextureCacheThread()
 	}
 }
 	
-// called in the MAIN thread after the ImageDecodeThread shuts down.
-//
-// Threads:  Tmain
-void LLTextureFetch::shutDownImageDecodeThread() 
-{
-	if(mImageDecodeThread)
-	{
-		llassert_always(mImageDecodeThread->isQuitting() || mImageDecodeThread->isStopped()) ;
-		mImageDecodeThread = NULL ;
-	}
-}
-
 // Threads:  Ttf
 void LLTextureFetch::startThread()
 {
@@ -3266,6 +3189,7 @@ void LLTextureFetch::endThread()
 // Threads:  Ttf
 void LLTextureFetch::threadedUpdate()
 {
+    LL_PROFILE_ZONE_SCOPED;
 	llassert_always(mHttpRequest);
 
 #if 0
@@ -3301,6 +3225,7 @@ void LLTextureFetch::threadedUpdate()
 // Threads:  Tmain
 void LLTextureFetch::sendRequestListToSimulators()
 {
+    LL_PROFILE_ZONE_SCOPED;
 	// All requests
 	const F32 REQUEST_DELTA_TIME = 0.10f; // 10 fps
 	
@@ -3351,7 +3276,6 @@ void LLTextureFetch::sendRequestListToSimulators()
 				req->mLastPacket >= req->mTotalPackets-1)
 			{
 				// We have all the packets... make sure this is high priority
-// 			req->setPriority(LLWorkerThread::PRIORITY_HIGH | req->mWorkPriority);
 				continue;
 			}
 			F32 elapsed = req->mRequestedDeltaTimer.getElapsedTimeF32();
@@ -3499,6 +3423,7 @@ void LLTextureFetch::sendRequestListToSimulators()
 // Locks:  Mw
 bool LLTextureFetchWorker::insertPacket(S32 index, U8* data, S32 size)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	mRequestedDeltaTimer.reset();
 	if (index >= mTotalPackets)
 	{
@@ -3531,6 +3456,7 @@ bool LLTextureFetchWorker::insertPacket(S32 index, U8* data, S32 size)
 
 void LLTextureFetchWorker::setState(e_state new_state)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	if (mFTType == FTT_SERVER_BAKE)
 	{
 	// NOTE: turning on these log statements is a reliable way to get
@@ -3552,7 +3478,7 @@ void LLTextureFetchWorker::setState(e_state new_state)
 			mSkippedStatesTime += d_time;
 		}
 	}
-	
+
 	mStateTimer.reset();
 	mState = new_state;
 }
@@ -3561,6 +3487,7 @@ void LLTextureFetchWorker::setState(e_state new_state)
 bool LLTextureFetch::receiveImageHeader(const LLHost& host, const LLUUID& id, U8 codec, U16 packets, U32 totalbytes,
 										U16 data_size, U8* data)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	LLTextureFetchWorker* worker = getWorker(id);
 	bool res = true;
 
@@ -3612,7 +3539,6 @@ bool LLTextureFetch::receiveImageHeader(const LLHost& host, const LLUUID& id, U8
 	llassert_always(totalbytes > 0);
 	llassert_always(data_size == FIRST_PACKET_SIZE || data_size == worker->mFileSize);
 	res = worker->insertPacket(0, data, data_size);
-	worker->setPriority(LLWorkerThread::PRIORITY_HIGH | worker->mWorkPriority);
 	worker->setState(LLTextureFetchWorker::LOAD_FROM_SIMULATOR);
 	worker->unlockWorkMutex();											// -Mw
 	return res;
@@ -3622,6 +3548,7 @@ bool LLTextureFetch::receiveImageHeader(const LLHost& host, const LLUUID& id, U8
 // Threads:  T*
 bool LLTextureFetch::receiveImagePacket(const LLHost& host, const LLUUID& id, U16 packet_num, U16 data_size, U8* data)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	LLTextureFetchWorker* worker = getWorker(id);
 	bool res = true;
 
@@ -3662,7 +3589,6 @@ bool LLTextureFetch::receiveImagePacket(const LLHost& host, const LLUUID& id, U1
 	if ((worker->mState == LLTextureFetchWorker::LOAD_FROM_SIMULATOR) ||
 		(worker->mState == LLTextureFetchWorker::LOAD_FROM_NETWORK))
 	{
-		worker->setPriority(LLWorkerThread::PRIORITY_HIGH | worker->mWorkPriority);
 		worker->setState(LLTextureFetchWorker::LOAD_FROM_SIMULATOR);
 	}
 	else
@@ -3707,10 +3633,23 @@ BOOL LLTextureFetch::isFromLocalCache(const LLUUID& id)
 	return from_cache ;
 }
 
+S32 LLTextureFetch::getFetchState(const LLUUID& id)
+{
+    S32 state = LLTextureFetchWorker::INVALID;
+    LLTextureFetchWorker* worker = getWorker(id);
+    if (worker && worker->haveWork())
+    {
+        state = worker->mState;
+    }
+
+    return state;
+}
+
 // Threads:  T*
 S32 LLTextureFetch::getFetchState(const LLUUID& id, F32& data_progress_p, F32& requested_priority_p,
 								  U32& fetch_priority_p, F32& fetch_dtime_p, F32& request_dtime_p, bool& can_use_http)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	S32 state = LLTextureFetchWorker::INVALID;
 	F32 data_progress = 0.0f;
 	F32 requested_priority = 0.0f;
@@ -3746,7 +3685,7 @@ S32 LLTextureFetch::getFetchState(const LLUUID& id, F32& data_progress_p, F32& r
 		{
 			requested_priority = worker->mImagePriority;
 		}
-		fetch_priority = worker->getPriority();
+		fetch_priority = worker->getImagePriority();
 		can_use_http = worker->getCanUseHTTP() ;
 		worker->unlockWorkMutex();										// -Mw
 	}
@@ -3760,19 +3699,6 @@ S32 LLTextureFetch::getFetchState(const LLUUID& id, F32& data_progress_p, F32& r
 
 void LLTextureFetch::dump()
 {
-	LL_INFOS(LOG_TXT) << "LLTextureFetch REQUESTS:" << LL_ENDL;
-	for (request_queue_t::iterator iter = mRequestQueue.begin();
-		 iter != mRequestQueue.end(); ++iter)
-	{
-		LLQueuedThread::QueuedRequest* qreq = *iter;
-		LLWorkerThread::WorkRequest* wreq = (LLWorkerThread::WorkRequest*)qreq;
-		LLTextureFetchWorker* worker = (LLTextureFetchWorker*)wreq->getWorkerClass();
-		LL_INFOS(LOG_TXT) << " ID: " << worker->mID
-						  << " PRI: " << llformat("0x%08x",wreq->getPriority())
-						  << " STATE: " << sStateDescs[worker->mState]
-						  << LL_ENDL;
-	}
-
 	LL_INFOS(LOG_TXT) << "LLTextureFetch ACTIVE_HTTP:" << LL_ENDL;
 	for (queue_t::const_iterator iter(mHTTPTextureQueue.begin());
 		 mHTTPTextureQueue.end() != iter;
@@ -3839,6 +3765,7 @@ bool LLTextureFetch::isHttpWaiter(const LLUUID & tid)
 // Locks:  -Mw (must not hold any worker when called)
 void LLTextureFetch::releaseHttpWaiters()
 {
+    LL_PROFILE_ZONE_SCOPED;
 	// Use mHttpSemaphore rather than mHTTPTextureQueue.size()
 	// to avoid a lock.  
 	if (mHttpSemaphore >= mHttpLowWater)
@@ -3935,7 +3862,6 @@ void LLTextureFetch::releaseHttpWaiters()
 		}
 		
 		worker->setState(LLTextureFetchWorker::SEND_HTTP_REQ);
-		worker->setPriority(LLWorkerThread::PRIORITY_HIGH | worker->mWorkPriority);
 		worker->unlockWorkMutex();										// -Mw
 
 		removeHttpWaiter(worker->mID);
@@ -4025,6 +3951,7 @@ void LLTextureFetch::commandDataBreak()
 // Threads:  T*
 void LLTextureFetch::cmdEnqueue(TFRequest * req)
 {
+    LL_PROFILE_ZONE_SCOPED;
 	lockQueue();														// +Mfq
 	mCommands.push_back(req);
 	unlockQueue();														// -Mfq
@@ -4035,6 +3962,7 @@ void LLTextureFetch::cmdEnqueue(TFRequest * req)
 // Threads:  T*
 LLTextureFetch::TFRequest * LLTextureFetch::cmdDequeue()
 {
+    LL_PROFILE_ZONE_SCOPED;
 	TFRequest * ret = 0;
 	
 	lockQueue();														// +Mfq
@@ -4051,6 +3979,7 @@ LLTextureFetch::TFRequest * LLTextureFetch::cmdDequeue()
 // Threads:  Ttf
 void LLTextureFetch::cmdDoWork()
 {
+    LL_PROFILE_ZONE_SCOPED;
 	if (mDebugPause)
 	{
 		return;  // debug: don't do any work
@@ -4141,7 +4070,7 @@ TFReqSendMetrics::~TFReqSendMetrics()
 bool
 TFReqSendMetrics::doWork(LLTextureFetch * fetcher)
 {
-	static const U32 report_priority(1);
+    LL_PROFILE_ZONE_SCOPED;
 	
 	//if (! gViewerAssetStatsThread1)
 	//	return true;
@@ -4184,7 +4113,6 @@ TFReqSendMetrics::doWork(LLTextureFetch * fetcher)
 		// Don't care about handle, this is a fire-and-forget operation.  
 		LLCoreHttpUtil::requestPostWithLLSD(&fetcher->getHttpRequest(),
 											fetcher->getMetricsPolicyClass(),
-											report_priority,
 											mCapsURL,
 											mStatsSD,
 											LLCore::HttpOptions::ptr_t(),
@@ -4246,971 +4174,6 @@ truncate_viewer_metrics(int max_regions, LLSD & metrics)
 
 } // end of anonymous namespace
 
-
-///////////////////////////////////////////////////////////////////////////////////////////
-//Start LLTextureFetchDebugger
-///////////////////////////////////////////////////////////////////////////////////////////
-//---------------------
-class LLDebuggerCacheReadResponder : public LLTextureCache::ReadResponder
-{
-public:
-	LLDebuggerCacheReadResponder(LLTextureFetchDebugger* debugger, S32 id, LLImageFormatted* image)
-		: mDebugger(debugger), mID(id)
-	{
-		setImage(image);
-	}
-	virtual void completed(bool success)
-	{
-		mDebugger->callbackCacheRead(mID, success, mFormattedImage, mImageSize, mImageLocal);
-	}
-private:
-	LLTextureFetchDebugger* mDebugger;
-	S32 mID;
-};
-
-class LLDebuggerCacheWriteResponder : public LLTextureCache::WriteResponder
-{
-public:
-	LLDebuggerCacheWriteResponder(LLTextureFetchDebugger* debugger, S32 id)
-		: mDebugger(debugger), mID(id)
-	{
-	}
-	virtual void completed(bool success)
-	{
-		mDebugger->callbackCacheWrite(mID, success);
-	}
-private:
-	LLTextureFetchDebugger* mDebugger;
-	S32 mID;
-};
-
-class LLDebuggerDecodeResponder : public LLImageDecodeThread::Responder
-{
-public:
-	LLDebuggerDecodeResponder(LLTextureFetchDebugger* debugger, S32 id)
-		: mDebugger(debugger), mID(id)
-	{
-	}
-	virtual void completed(bool success, LLImageRaw* raw, LLImageRaw* aux)
-	{
-		mDebugger->callbackDecoded(mID, success, raw, aux);
-	}
-private:
-	LLTextureFetchDebugger* mDebugger;
-	S32 mID;
-};
-
-
-LLTextureFetchDebugger::LLTextureFetchDebugger(LLTextureFetch* fetcher, LLTextureCache* cache, LLImageDecodeThread* imagedecodethread) :
-	LLCore::HttpHandler(),
-	mFetcher(fetcher),
-	mTextureCache(cache),
-	mImageDecodeThread(imagedecodethread),
-	mHttpHeaders(),
-	mHttpPolicyClass(fetcher->getPolicyClass()),
-	mNbCurlCompleted(0),
-	mTempIndex(0),
-	mHistoryListIndex(0)
-{
-	init();
-}
-	
-LLTextureFetchDebugger::~LLTextureFetchDebugger()
-{
-	mFetchingHistory.clear();
-	mStopDebug = TRUE;
-	tryToStopDebug();
-}
-
-void LLTextureFetchDebugger::init()
-{
-	setDebuggerState(IDLE);
-	
-	mCacheReadTime = -1.f;
-	mCacheWriteTime = -1.f;
-	mDecodingTime = -1.f;
-	mHTTPTime = -1.f;
-	mGLCreationTime = -1.f;
-
-	mTotalFetchingTime = 0.f;
-	mRefetchVisCacheTime = -1.f;
-	mRefetchVisHTTPTime = -1.f;
-	mRefetchAllCacheTime = -1.f;
-	mRefetchAllHTTPTime = -1.f;
-
-	mNumFetchedTextures = 0;
-	mNumCacheHits = 0;
-	mNumVisibleFetchedTextures = 0;
-	mNumVisibleFetchingRequests = 0;
-	mFetchedData = 0;
-	mDecodedData = 0;
-	mVisibleFetchedData = 0;
-	mVisibleDecodedData = 0;
-	mRenderedData = 0;
-	mRenderedDecodedData = 0;
-	mFetchedPixels = 0;
-	mRenderedPixels = 0;
-	mRefetchedVisData = 0;
-	mRefetchedVisPixels = 0;
-	mRefetchedAllData = 0;
-	mRefetchedAllPixels = 0;
-
-	mFreezeHistory = FALSE;
-	mStopDebug = FALSE;
-	mClearHistory = FALSE;
-	mRefetchNonVis = FALSE;
-	
-	mNbCurlRequests = 0;
-
-	if (! mHttpHeaders)
-	{
-        mHttpHeaders = LLCore::HttpHeaders::ptr_t(new LLCore::HttpHeaders);
-		mHttpHeaders->append(HTTP_OUT_HEADER_ACCEPT, HTTP_CONTENT_IMAGE_X_J2C);
-	}
-}
-
-void LLTextureFetchDebugger::startWork(e_debug_state state)
-{
-	switch(state)
-	{
-		case IDLE:
-			break;
-		case START_DEBUG:
-			startDebug();
-			break;
-		case READ_CACHE:			
-			debugCacheRead();
-			break;
-		case WRITE_CACHE:
-			debugCacheWrite();
-			break;
-		case DECODING:
-			debugDecoder();
-			break;
-		case HTTP_FETCHING:
-			debugHTTP();
-			break;
-		case GL_TEX:
-			debugGLTextureCreation();
-			break;
-		case REFETCH_VIS_CACHE:
-			debugRefetchVisibleFromCache();
-			break;
-		case REFETCH_VIS_HTTP:
-			debugRefetchVisibleFromHTTP();
-			break;
-		case REFETCH_ALL_CACHE:
-			debugRefetchAllFromCache();
-			break;
-		case REFETCH_ALL_HTTP:
-			debugRefetchAllFromHTTP();
-			break;
-		default:
-			break;
-	}
-	return;
-}
-
-void LLTextureFetchDebugger::startDebug()
-{
-	//lock the fetcher
-	mFetcher->lockFetcher(true);
-	mFreezeHistory = TRUE;
-	mFetcher->resetLoadSource();
-
-	//clear the current fetching queue
-	gTextureList.clearFetchingRequests();
-
-	setDebuggerState(START_DEBUG);
-}
-
-bool LLTextureFetchDebugger::processStartDebug(F32 max_time)
-{
-	mTimer.reset();
-
-	//wait for all works to be done
-	while(1)
-	{
-		S32 pending = 0;
-		pending += LLAppViewer::getTextureCache()->update(1); 
-		pending += LLAppViewer::getImageDecodeThread()->update(1); 
-		// pending += LLAppViewer::getTextureFetch()->update(1);  // This causes infinite recursion in some cases
-		pending += mNbCurlRequests;
-		if(!pending)
-		{
-			break;
-		}
-
-		if(mTimer.getElapsedTimeF32() > max_time)
-		{
-			return false;
-		}
-	}
-
-	//collect statistics
-	mTotalFetchingTime = gTextureTimer.getElapsedTimeF32() - mTotalFetchingTime;
-	
-	std::set<LLUUID> fetched_textures;
-	S32 size = mFetchingHistory.size();
-	for(S32 i = 0 ; i < size; i++)
-	{
-		bool in_list = true;
-		if(fetched_textures.find(mFetchingHistory[i].mID) == fetched_textures.end())
-		{
-			fetched_textures.insert(mFetchingHistory[i].mID);
-			in_list = false;
-		}
-
-        std::vector<LLViewerFetchedTexture*> textures;
-        LLViewerTextureManager::findFetchedTextures(mFetchingHistory[i].mID, textures);
-        std::vector<LLViewerFetchedTexture*>::iterator iter = textures.begin();
-        while (iter != textures.end())
-        {
-            LLViewerFetchedTexture* tex = *iter++;
-            // fetched data will be counted for both ui and regular elements
-            if (tex && tex->isJustBound()) //visible
-            {
-                if (!in_list)
-                {
-                    mNumVisibleFetchedTextures++;
-                }
-                mNumVisibleFetchingRequests++;
-
-                mVisibleFetchedData += mFetchingHistory[i].mFetchedSize;
-                mVisibleDecodedData += mFetchingHistory[i].mDecodedSize;
-
-                if (tex->getDiscardLevel() >= mFetchingHistory[i].mDecodedLevel)
-                {
-                    mRenderedData += mFetchingHistory[i].mFetchedSize;
-                    mRenderedDecodedData += mFetchingHistory[i].mDecodedSize;
-                    mRenderedPixels += tex->getWidth() * tex->getHeight();
-                }
-            }
-        }
-	}
-
-	mNumFetchedTextures = fetched_textures.size();
-
-	return true;
-}
-
-void LLTextureFetchDebugger::tryToStopDebug()
-{
-	if(!mStopDebug)
-	{
-		return;
-	}
-
-	//clear the current debug work
-	S32 size = mFetchingHistory.size();
-	switch(mDebuggerState)
-	{
-	case READ_CACHE:		
-		for(S32 i = 0 ; i < size; i++)
-		{
-			if (mFetchingHistory[i]. mCacheHandle != LLTextureCache::nullHandle())
-			{
-				mTextureCache->readComplete(mFetchingHistory[i].mCacheHandle, true);
-			}
- 		}	
-		break;
-	case WRITE_CACHE:
-		for(S32 i = 0 ; i < size; i++)
-		{
-			if (mFetchingHistory[i].mCacheHandle != LLTextureCache::nullHandle())
-			{
-				mTextureCache->writeComplete(mFetchingHistory[i].mCacheHandle, true);
-			}
-		}
-		break;
-	case DECODING:
-		break;
-	case HTTP_FETCHING:
-		break;
-	case GL_TEX:
-		break;
-	case REFETCH_VIS_CACHE:
-		break;
-	case REFETCH_VIS_HTTP:
-		break;
-	case REFETCH_ALL_CACHE:
-		mRefetchList.clear();
-		break;
-	case REFETCH_ALL_HTTP:
-		mRefetchList.clear();
-		break;
-	default:
-		break;
-	}
-
-	if(update(0.005f))
-	{
-		//unlock the fetcher
-		mFetcher->lockFetcher(false);
-		mFetcher->resetLoadSource();
-		mFreezeHistory = FALSE;		
-		mStopDebug = FALSE;
-
-		if(mClearHistory)
-		{
-			mFetchingHistory.clear();
-			mHandleToFetchIndex.clear();
-			init();	
-			mTotalFetchingTime = gTextureTimer.getElapsedTimeF32(); //reset
-		}
-	}
-}
-
-//called in the main thread and when the fetching queue is empty
-void LLTextureFetchDebugger::clearHistory()
-{
-	mClearHistory = TRUE;	
-}
-
-void LLTextureFetchDebugger::addHistoryEntry(LLTextureFetchWorker* worker)
-{
-	if(worker->mRawImage.isNull() || worker->mFormattedImage.isNull())
-	{
-		return;
-	}
-
-	if(mFreezeHistory)
-	{
-		if(mDebuggerState == REFETCH_VIS_CACHE || mDebuggerState == REFETCH_VIS_HTTP)
-		{
-			mRefetchedVisPixels += worker->mRawImage->getWidth() * worker->mRawImage->getHeight();
-			mRefetchedVisData += worker->mFormattedImage->getDataSize();
-		}
-		else
-		{
-			mRefetchedAllPixels += worker->mRawImage->getWidth() * worker->mRawImage->getHeight();
-			mRefetchedAllData += worker->mFormattedImage->getDataSize();
-
-			// refetch list only requests/creates normal images, so requesting ui='false'
-			LLViewerFetchedTexture* tex = LLViewerTextureManager::findFetchedTexture(worker->mID, TEX_LIST_STANDARD);
-			if(tex && mRefetchList[tex].begin() != mRefetchList[tex].end())
-			{
-				if(worker->mDecodedDiscard == mFetchingHistory[mRefetchList[tex][0]].mDecodedLevel)
-				{
-					mRefetchList[tex].erase(mRefetchList[tex].begin());
-				}
-			}
-		}
-		return;
-	}
-
-	if(worker->mInCache)
-	{
-		mNumCacheHits++;
-	}
-	mFetchedData += worker->mFormattedImage->getDataSize();
-	mDecodedData += worker->mRawImage->getDataSize();
-	mFetchedPixels += worker->mRawImage->getWidth() * worker->mRawImage->getHeight();
-
-	mFetchingHistory.push_back(FetchEntry(worker->mID, worker->mDesiredSize, worker->mDecodedDiscard, 
-		worker->mFormattedImage->getDataSize(), worker->mRawImage->getDataSize()));
-}
-
-void LLTextureFetchDebugger::lockCache()
-{
-}
-	
-void LLTextureFetchDebugger::unlockCache()
-{
-}
-	
-void LLTextureFetchDebugger::debugCacheRead()
-{
-	lockCache();
-	llassert_always(mDebuggerState == IDLE);
-	mTimer.reset();
-	setDebuggerState(READ_CACHE);
-	mCacheReadTime = -1.f;
-
-	S32 size = mFetchingHistory.size();
-	for(S32 i = 0 ; i < size ; i++)
-	{		
-		mFetchingHistory[i].mFormattedImage = NULL;
-		mFetchingHistory[i].mCacheHandle = mTextureCache->readFromCache(mFetchingHistory[i].mID, LLWorkerThread::PRIORITY_NORMAL, 0, mFetchingHistory[i].mFetchedSize, 
-			new LLDebuggerCacheReadResponder(this, i, mFetchingHistory[i].mFormattedImage));
-	}
-}
-	
-void LLTextureFetchDebugger::clearCache()
-{
-	S32 size = mFetchingHistory.size();
-	{
-		std::set<LLUUID> deleted_list;
-		for(S32 i = 0 ; i < size ; i++)
-		{
-			if(deleted_list.find(mFetchingHistory[i].mID) == deleted_list.end())
-			{
-				deleted_list.insert(mFetchingHistory[i].mID);
-				mTextureCache->removeFromCache(mFetchingHistory[i].mID);
-			}
-		}
-	}
-}
-
-void LLTextureFetchDebugger::debugCacheWrite()
-{
-	//remove from cache
-	clearCache();
-
-	lockCache();
-	llassert_always(mDebuggerState == IDLE);
-	mTimer.reset();
-	setDebuggerState(WRITE_CACHE);
-	mCacheWriteTime = -1.f;
-
-	S32 size = mFetchingHistory.size();
-	for(S32 i = 0 ; i < size ; i++)
-	{		
-		if(mFetchingHistory[i].mFormattedImage.notNull())
-		{
-			mFetchingHistory[i].mCacheHandle = mTextureCache->writeToCache(mFetchingHistory[i].mID, LLWorkerThread::PRIORITY_NORMAL, 
-				mFetchingHistory[i].mFormattedImage->getData(), mFetchingHistory[i].mFetchedSize,
-				mFetchingHistory[i].mDecodedLevel == 0 ? mFetchingHistory[i].mFetchedSize : mFetchingHistory[i].mFetchedSize + 1, 
-				NULL, 0, new LLDebuggerCacheWriteResponder(this, i));					
-		}
-	}
-}
-
-void LLTextureFetchDebugger::lockDecoder()
-{
-}
-	
-void LLTextureFetchDebugger::unlockDecoder()
-{
-}
-
-void LLTextureFetchDebugger::debugDecoder()
-{
-	lockDecoder();
-	llassert_always(mDebuggerState == IDLE);
-	mTimer.reset();
-	setDebuggerState(DECODING);
-	mDecodingTime = -1.f;
-
-	S32 size = mFetchingHistory.size();
-	for(S32 i = 0 ; i < size ; i++)
-	{		
-		if(mFetchingHistory[i].mFormattedImage.isNull())
-		{
-			continue;
-		}
-
-		mImageDecodeThread->decodeImage(mFetchingHistory[i].mFormattedImage, LLWorkerThread::PRIORITY_NORMAL, 
-			mFetchingHistory[i].mDecodedLevel, mFetchingHistory[i].mNeedsAux,
-			new LLDebuggerDecodeResponder(this, i));
-	}
-}
-
-void LLTextureFetchDebugger::debugHTTP()
-{
-	llassert_always(mDebuggerState == IDLE);
-
-	LLViewerRegion* region = gAgent.getRegion();
-	if (!region)
-	{
-		LL_INFOS(LOG_TXT) << "Fetch Debugger : Current region undefined. Cannot fetch textures through HTTP." << LL_ENDL;
-		return;
-	}
-	
-	mHTTPUrl = region->getViewerAssetUrl();
-	if (mHTTPUrl.empty())
-	{
-		LL_INFOS(LOG_TXT) << "Fetch Debugger : Current region URL undefined. Cannot fetch textures through HTTP." << LL_ENDL;
-		return;
-	}
-	
-	mTimer.reset();
-	setDebuggerState(HTTP_FETCHING);
-	mHTTPTime = -1.f;
-	
-	S32 size = mFetchingHistory.size();
-	for (S32 i = 0 ; i < size ; i++)
-	{
-		mFetchingHistory[i].mCurlState = FetchEntry::CURL_NOT_DONE;
-		mFetchingHistory[i].mCurlReceivedSize = 0;
-		mFetchingHistory[i].mFormattedImage = NULL;
-	}
-	mNbCurlRequests = 0;
-	mNbCurlCompleted = 0;
-	
-	fillCurlQueue();
-}
-
-S32 LLTextureFetchDebugger::fillCurlQueue()
-{
-	if(mStopDebug) //stop
-	{
-		mNbCurlCompleted = mFetchingHistory.size();
-		return 0;
-	}
-	if (mNbCurlRequests > HTTP_NONPIPE_REQUESTS_LOW_WATER)
-	{
-		return mNbCurlRequests;
-	}
-	
-	S32 size = mFetchingHistory.size();
-	for (S32 i = 0 ; i < size ; i++)
-	{		
-		if (mFetchingHistory[i].mCurlState != FetchEntry::CURL_NOT_DONE)
-		{
-			continue;
-		}
-		std::string texture_url = mHTTPUrl + "/?texture_id=" + mFetchingHistory[i].mID.asString().c_str();
-		S32 requestedSize = mFetchingHistory[i].mRequestedSize;
-		// We request the whole file if the size was not set.
-		requestedSize = llmax(0,requestedSize);
-		// We request the whole file if the size was set to an absurdly high value (meaning all file)
-		requestedSize = (requestedSize == 33554432 ? 0 : requestedSize);
-
-		LLCore::HttpHandle handle = mFetcher->getHttpRequest().requestGetByteRange(mHttpPolicyClass,
-																				   LLWorkerThread::PRIORITY_LOWBITS,
-																				   texture_url,
-																				   0,
-																				   requestedSize,
-																				   LLCore::HttpOptions::ptr_t(),
-																				   mHttpHeaders,
-                                                                                   LLCore::HttpHandler::ptr_t(this, &NoOpDeletor));
-		if (LLCORE_HTTP_HANDLE_INVALID != handle)
-		{
-			mHandleToFetchIndex[handle] = i;
-			mFetchingHistory[i].mHttpHandle = handle;
-			mFetchingHistory[i].mCurlState = FetchEntry::CURL_IN_PROGRESS;
-			mNbCurlRequests++;
-			if (mNbCurlRequests >= HTTP_NONPIPE_REQUESTS_HIGH_WATER)	// emulate normal pipeline
-			{
-				break;
-			}
-		}
-		else 
-		{
-			// Failed to queue request, log it and mark it done.
-			LLCore::HttpStatus status(mFetcher->getHttpRequest().getStatus());
-
-			LL_WARNS(LOG_TXT) << "Couldn't issue HTTP request in debugger for texture "
-							  << mFetchingHistory[i].mID
-							  << ", status: " << status.toTerseString()
-							  << " reason:  " << status.toString()
-							  << LL_ENDL;
-			mFetchingHistory[i].mCurlState = FetchEntry::CURL_DONE;
-		}
-	}
-	//LL_INFOS(LOG_TXT) << "Fetch Debugger : Having " << mNbCurlRequests << " requests through the curl thread." << LL_ENDL;
-	return mNbCurlRequests;
-}
-
-void LLTextureFetchDebugger::debugGLTextureCreation()
-{
-	llassert_always(mDebuggerState == IDLE);
-	setDebuggerState(GL_TEX);
-	mTempTexList.clear();
-
-	S32 size = mFetchingHistory.size();
-	for(S32 i = 0 ; i < size ; i++)
-	{
-		if(mFetchingHistory[i].mRawImage.notNull())
-		{
-            std::vector<LLViewerFetchedTexture*> textures;
-            gTextureList.findTexturesByID(mFetchingHistory[i].mID, textures);
-            std::vector<LLViewerFetchedTexture*>::iterator iter = textures.begin();
-            while (iter != textures.end())
-            {
-                LLViewerFetchedTexture* tex = *iter++;
-                if (tex && !tex->isForSculptOnly())
-                {
-                    tex->destroyGLTexture();
-                    mTempTexList.push_back(tex);
-                }
-            }
-		}
-	}
-	
-	mGLCreationTime = -1.f;
-	mTempIndex = 0;
-	mHistoryListIndex = 0;
-	
-	return;
-}
-
-bool LLTextureFetchDebugger::processGLCreation(F32 max_time)
-{
-	mTimer.reset();
-
-	bool done = true;
-	S32 size = mFetchingHistory.size();
-	S32 size1 = mTempTexList.size();
-	for(; mHistoryListIndex < size && mTempIndex < size1; mHistoryListIndex++)
-	{
-		if(mFetchingHistory[mHistoryListIndex].mRawImage.notNull())
-		{
-			if(mFetchingHistory[mHistoryListIndex].mID == mTempTexList[mTempIndex]->getID())
-			{
-				mTempTexList[mTempIndex]->createGLTexture(mFetchingHistory[mHistoryListIndex].mDecodedLevel, 
-					mFetchingHistory[mHistoryListIndex].mRawImage, 0, TRUE, mTempTexList[mTempIndex]->getBoostLevel());
-				mTempIndex++;
-			}
-		}
-
-		if(mTimer.getElapsedTimeF32() > max_time)
-		{
-			done = false;
-			break;
-		}
-	}
-
-	if(mGLCreationTime < 0.f)
-	{
-		mGLCreationTime = mTimer.getElapsedTimeF32() ;
-	}
-	else
-	{
-		mGLCreationTime += mTimer.getElapsedTimeF32() ;
-	}
-
-	return done;
-}
-
-//clear fetching results of all textures.
-void LLTextureFetchDebugger::clearTextures()
-{
-	S32 size = mFetchingHistory.size();
-	for(S32 i = 0 ; i < size ; i++)
-	{
-        std::vector<LLViewerFetchedTexture*> textures;
-        gTextureList.findTexturesByID(mFetchingHistory[i].mID, textures);
-        std::vector<LLViewerFetchedTexture*>::iterator iter = textures.begin();
-        while (iter != textures.end())
-        {
-            LLViewerFetchedTexture* tex = *iter++;
-            if (tex)
-            {
-                tex->clearFetchedResults();
-            }
-        }
-	}
-}
-
-void LLTextureFetchDebugger::makeRefetchList()
-{
-	mRefetchList.clear();
-	S32 size = mFetchingHistory.size();
-	for(S32 i = 0 ; i < size; i++)
-	{		
-		LLViewerFetchedTexture* tex = LLViewerTextureManager::getFetchedTexture(mFetchingHistory[i].mID);
-		if(tex && tex->isJustBound()) //visible
-		{
-			continue; //the texture fetch pipeline will take care of visible textures.
-		}
-
-		// todo: Will attempt to refetch icons and ui elements as normal images (boost_none)
-		// thus will create unnecessary LLViewerFetchedTexture, consider supporting separate UI textures
-		mRefetchList[tex].push_back(i); 		
-	}
-}
-
-void LLTextureFetchDebugger::scanRefetchList()
-{
-	if(mStopDebug)
-	{
-		return;
-	}
-	if(!mRefetchNonVis)
-	{
-		return;
-	}
-
-	for(std::map< LLPointer<LLViewerFetchedTexture>, std::vector<S32> >::iterator iter = mRefetchList.begin();
-		iter != mRefetchList.end(); )
-	{
-		if(iter->second.empty())
-		{
-			gTextureList.setDebugFetching(iter->first, -1);
-			mRefetchList.erase(iter++);		// This is the correct method to "erase and move on" in an std::map
-		}
-		else
-		{
-			gTextureList.setDebugFetching(iter->first, mFetchingHistory[iter->second[0]].mDecodedLevel);
-			++iter;
-		}
-	}
-}
-
-void LLTextureFetchDebugger::debugRefetchVisibleFromCache()
-{
-	llassert_always(mDebuggerState == IDLE);
-	setDebuggerState(REFETCH_VIS_CACHE);
-
-	clearTextures();
-	mFetcher->setLoadSource(LLTextureFetch::FROM_ALL);
-	
-	mTimer.reset();
-	mFetcher->lockFetcher(false);
-	mRefetchVisCacheTime = -1.f;
-	mRefetchedVisData = 0;
-	mRefetchedVisPixels = 0;
-}
-
-void LLTextureFetchDebugger::debugRefetchVisibleFromHTTP()
-{
-	llassert_always(mDebuggerState == IDLE);
-	setDebuggerState(REFETCH_VIS_HTTP);
-
-	clearTextures();
-	mFetcher->setLoadSource(LLTextureFetch::FROM_HTTP_ONLY);
-
-	mTimer.reset();
-	mFetcher->lockFetcher(false);
-	mRefetchVisHTTPTime = -1.f;
-	mRefetchedVisData = 0;
-	mRefetchedVisPixels = 0;
-}
-
-void LLTextureFetchDebugger::debugRefetchAllFromCache()
-{
-	llassert_always(mDebuggerState == IDLE);
-	setDebuggerState(REFETCH_ALL_CACHE);
-
-	clearTextures();
-	makeRefetchList();
-	mFetcher->setLoadSource(LLTextureFetch::FROM_ALL);
-
-	mTimer.reset();
-	mFetcher->lockFetcher(false);
-	mRefetchAllCacheTime = -1.f;
-	mRefetchedAllData = 0;
-	mRefetchedAllPixels = 0;
-	mRefetchNonVis = FALSE;
-}
-
-void LLTextureFetchDebugger::debugRefetchAllFromHTTP()
-{
-	llassert_always(mDebuggerState == IDLE);
-	setDebuggerState(REFETCH_ALL_HTTP);
-
-	clearTextures();
-	makeRefetchList();
-	mFetcher->setLoadSource(LLTextureFetch::FROM_HTTP_ONLY);
-
-	mTimer.reset();
-	mFetcher->lockFetcher(false);
-	mRefetchAllHTTPTime = -1.f;
-	mRefetchedAllData = 0;
-	mRefetchedAllPixels = 0;
-	mRefetchNonVis = TRUE;
-}
-
-bool LLTextureFetchDebugger::update(F32 max_time)
-{
-	switch(mDebuggerState)
-	{
-	case START_DEBUG:
-		if(processStartDebug(max_time))
-		{
-			setDebuggerState(IDLE);
-		}
-		break;
-	case READ_CACHE:
-		if(!mTextureCache->update(1))
-		{
-			mCacheReadTime = mTimer.getElapsedTimeF32() ;
-			setDebuggerState(IDLE);
-			unlockCache();
-		}
-		break;
-	case WRITE_CACHE:
-		if(!mTextureCache->update(1))
-		{
-			mCacheWriteTime = mTimer.getElapsedTimeF32() ;
-			setDebuggerState(IDLE);
-			unlockCache();
-		}
-		break;
-	case DECODING:
-		if(!mImageDecodeThread->update(1))
-		{
-			mDecodingTime =  mTimer.getElapsedTimeF32() ;
-			setDebuggerState(IDLE);
-			unlockDecoder();
-		}
-		break;
-	case HTTP_FETCHING:
-		// Do some notifications...
-		mFetcher->getHttpRequest().update(10);
-		if (!fillCurlQueue() && mNbCurlCompleted == mFetchingHistory.size())
-		{
-			mHTTPTime =  mTimer.getElapsedTimeF32() ;
-			setDebuggerState(IDLE);
-		}
-		break;
-	case GL_TEX:
-		if(processGLCreation(max_time))
-		{
-			setDebuggerState(IDLE);
-			mTempTexList.clear();
-		}
-		break;
-	case REFETCH_VIS_CACHE:
-		if (LLAppViewer::getTextureFetch()->getNumRequests() == 0)
-		{
-			mRefetchVisCacheTime = mTimer.getElapsedTimeF32() ;
-			setDebuggerState(IDLE);
-			mFetcher->lockFetcher(true);
-			mFetcher->resetLoadSource();
-		}
-		break;
-	case REFETCH_VIS_HTTP:
-		if (LLAppViewer::getTextureFetch()->getNumRequests() == 0)
-		{
-			mRefetchVisHTTPTime = mTimer.getElapsedTimeF32() ;
-			setDebuggerState(IDLE);
-			mFetcher->lockFetcher(true);
-			mFetcher->resetLoadSource();
-		}
-		break;
-	case REFETCH_ALL_CACHE:
-		scanRefetchList();
-		if (LLAppViewer::getTextureFetch()->getNumRequests() == 0)
-		{
-			if(!mRefetchNonVis)
-			{
-				mRefetchNonVis = TRUE; //start to fetch non-vis
-				scanRefetchList();
-				break;
-			}
-
-			mRefetchAllCacheTime = mTimer.getElapsedTimeF32() ;
-			setDebuggerState(IDLE); 
-			mFetcher->lockFetcher(true);
-			mFetcher->resetLoadSource();
-			mRefetchList.clear();
-			mRefetchNonVis = FALSE;
-		}
-		break;
-	case REFETCH_ALL_HTTP:
-		scanRefetchList();
-		if (LLAppViewer::getTextureFetch()->getNumRequests() == 0)
-		{
-			mRefetchAllHTTPTime = mTimer.getElapsedTimeF32() ;
-			setDebuggerState(IDLE);
-			mFetcher->lockFetcher(true);
-			mFetcher->resetLoadSource();
-			mRefetchList.clear();
-			mRefetchNonVis = FALSE;
-		}
-		break;
-	default:
-		setDebuggerState(IDLE);
-		break;
-	}
-
-	return mDebuggerState == IDLE;
-}
-
-void LLTextureFetchDebugger::onCompleted(LLCore::HttpHandle handle, LLCore::HttpResponse * response)
-{
-	handle_fetch_map_t::iterator iter(mHandleToFetchIndex.find(handle));
-	if (mHandleToFetchIndex.end() == iter)
-	{
-		LL_INFOS(LOG_TXT) << "Fetch Debugger : Couldn't find handle " << handle << " in fetch list." << LL_ENDL;
-		return;
-	}
-	
-	S32 fetch_ind(iter->second);
-	mHandleToFetchIndex.erase(iter);
-	if (fetch_ind >= mFetchingHistory.size() || mFetchingHistory[fetch_ind].mHttpHandle != handle)
-	{
-		LL_INFOS(LOG_TXT) << "Fetch Debugger : Handle and fetch object in disagreement.  Punting." << LL_ENDL;
-	}
-	else
-	{
-		callbackHTTP(mFetchingHistory[fetch_ind], response);
-		mFetchingHistory[fetch_ind].mHttpHandle = LLCORE_HTTP_HANDLE_INVALID;	// Not valid after notification
-	}
-}
-
-void LLTextureFetchDebugger::callbackCacheRead(S32 id, bool success, LLImageFormatted* image,
-						   S32 imagesize, BOOL islocal)
-{
-	if (success)
-	{
-		mFetchingHistory[id].mFormattedImage = image;
-	}
-	mTextureCache->readComplete(mFetchingHistory[id].mCacheHandle, false);
-	mFetchingHistory[id].mCacheHandle = LLTextureCache::nullHandle();
-}
-
-void LLTextureFetchDebugger::callbackCacheWrite(S32 id, bool success)
-{
-	mTextureCache->writeComplete(mFetchingHistory[id].mCacheHandle);
-	mFetchingHistory[id].mCacheHandle = LLTextureCache::nullHandle();
-}
-
-void LLTextureFetchDebugger::callbackDecoded(S32 id, bool success, LLImageRaw* raw, LLImageRaw* aux)
-{
-	if (success)
-	{
-		llassert_always(raw);
-		mFetchingHistory[id].mRawImage = raw;
-	}
-}
-
-void LLTextureFetchDebugger::callbackHTTP(FetchEntry & fetch, LLCore::HttpResponse * response)
-{
-	static const LLCore::HttpStatus par_status(HTTP_PARTIAL_CONTENT);
-	
-	LLCore::HttpStatus status(response->getStatus());
-	mNbCurlRequests--;
-	mNbCurlCompleted++;
-	fetch.mCurlState = FetchEntry::CURL_DONE;
-	if (status)
-	{
-		const bool partial(par_status == status);
-		LLCore::BufferArray * ba(response->getBody());	// *Not* holding reference to body
-		
-		S32 data_size = ba ? ba->size() : 0;
-		fetch.mCurlReceivedSize += data_size;
-		//LL_INFOS(LOG_TXT) << "Fetch Debugger : got results for " << fetch.mID << ", data_size = " << data_size << ", received = " << fetch.mCurlReceivedSize << ", requested = " << fetch.mRequestedSize << ", partial = " << partial << LL_ENDL;
-		if ((fetch.mCurlReceivedSize >= fetch.mRequestedSize) || !partial || (fetch.mRequestedSize == 600))
-		{
-			U8* d_buffer = (U8*)ll_aligned_malloc_16(data_size);
-			if (ba)
-			{
-				ba->read(0, d_buffer, data_size);
-			}
-			
-			llassert_always(fetch.mFormattedImage.isNull());
-			{
-				// For now, create formatted image based on extension
-				std::string texture_url = mHTTPUrl + "/?texture_id=" + fetch.mID.asString().c_str();
-				std::string extension = gDirUtilp->getExtension(texture_url);
-				fetch.mFormattedImage = LLImageFormatted::createFromType(LLImageBase::getCodecFromExtension(extension));
-				if (fetch.mFormattedImage.isNull())
-				{
-					fetch.mFormattedImage = new LLImageJ2C; // default
-				}
-			}
-						
-			fetch.mFormattedImage->setData(d_buffer, data_size);	
-		}
-	}
-	else //failed
-	{
-		LL_INFOS(LOG_TXT) << "Fetch Debugger : CURL GET FAILED,  ID = " << fetch.mID
-						  << ", status: " << status.toTerseString()
-						  << " reason:  " << status.toString() << LL_ENDL;
-	}
-}
-
-
-//---------------------
-///////////////////////////////////////////////////////////////////////////////////////////
-//End LLTextureFetchDebugger
-///////////////////////////////////////////////////////////////////////////////////////////
-
 LLTextureFetchTester::LLTextureFetchTester() : LLMetricPerformanceTesterBasic(sTesterName) 
 {
 	mTextureFetchTime = 0;
diff --git a/indra/newview/lltexturefetch.h b/indra/newview/lltexturefetch.h
index bf6732963f..3ca88422a2 100644
--- a/indra/newview/lltexturefetch.h
+++ b/indra/newview/lltexturefetch.h
@@ -48,7 +48,6 @@ class LLTextureFetchWorker;
 class LLImageDecodeThread;
 class LLHost;
 class LLViewerAssetStats;
-class LLTextureFetchDebugger;
 class LLTextureCache;
 class LLTextureFetchTester;
 
@@ -59,7 +58,9 @@ class LLTextureFetch : public LLWorkerThread
 	friend class LLTextureFetchWorker;
 	
 public:
-	LLTextureFetch(LLTextureCache* cache, LLImageDecodeThread* imagedecodethread, bool threaded, bool qa_mode);
+    static std::string getStateString(S32 state);
+
+	LLTextureFetch(LLTextureCache* cache, bool threaded, bool qa_mode);
 	~LLTextureFetch();
 
 	class TFRequest;
@@ -116,10 +117,11 @@ public:
     // Threads:  T*
 	BOOL isFromLocalCache(const LLUUID& id);
 
-	// @return	Magic number giving the internal state of the
-	//			request.  We should make these codes public if we're
-	//			going to return them as a status value.
-	//
+    // get the current fetch state, if any, from the given UUID
+    S32 getFetchState(const LLUUID& id);
+
+	// @return	Fetch state of given image and associates statistics
+	//          See also getStateString
     // Threads:  T*
 	S32 getFetchState(const LLUUID& id, F32& decode_progress_p, F32& requested_priority_p,
 					  U32& fetch_priority_p, F32& fetch_dtime_p, F32& request_dtime_p, bool& can_use_http);
@@ -322,7 +324,6 @@ private:
 	LLMutex mNetworkQueueMutex; //to protect mNetworkQueue, mHTTPTextureQueue and mCancelQueue.
 
 	LLTextureCache* mTextureCache;
-	LLImageDecodeThread* mImageDecodeThread;
 	
 	// Map of all requests by UUID
 	typedef std::map<LLUUID,LLTextureFetchWorker*> map_t;
@@ -409,10 +410,6 @@ public:
 	static LLTextureFetchTester* sTesterp;
 
 private:
-	//debug use
-	LLTextureFetchDebugger* mFetchDebugger;
-	bool mFetcherLocked;
-	
 	e_tex_source mFetchSource;
 	e_tex_source mOriginFetchSource;
 
@@ -420,10 +417,6 @@ private:
 	//LLAdaptiveRetryPolicy mFetchRetryPolicy;
 	
 public:
-	//debug use
-	LLTextureFetchDebugger* getFetchDebugger() { return mFetchDebugger;}
-	void lockFetcher(bool lock) { mFetcherLocked = lock;}
-
 	void setLoadSource(e_tex_source source) {mFetchSource = source;}
 	void resetLoadSource() {mFetchSource = mOriginFetchSource;}
 	bool canLoadFromCache() { return mFetchSource != FROM_HTTP_ONLY;}
@@ -431,216 +424,6 @@ public:
 
 //debug use
 class LLViewerFetchedTexture;
-class LLTextureFetchDebugger : public LLCore::HttpHandler
-{
-	friend class LLTextureFetch;
-public:
-	LLTextureFetchDebugger(LLTextureFetch* fetcher, LLTextureCache* cache, LLImageDecodeThread* imagedecodethread) ;
-	~LLTextureFetchDebugger();
-
-public:
-	enum e_debug_state
-	{
-		IDLE = 0,
-		START_DEBUG,
-		READ_CACHE,
-		WRITE_CACHE,
-		DECODING,
-		HTTP_FETCHING,
-		GL_TEX,
-		REFETCH_VIS_CACHE,
-		REFETCH_VIS_HTTP,
-		REFETCH_ALL_CACHE,
-		REFETCH_ALL_HTTP,
-		INVALID
-	};
-
-private:	
-	struct FetchEntry
-	{
-		enum e_curl_state
-		{
-			CURL_NOT_DONE = 0,
-			CURL_IN_PROGRESS,
-			CURL_DONE
-		};
-		LLUUID mID;
-		S32 mRequestedSize;
-		S32 mDecodedLevel;
-		S32 mFetchedSize;
-		S32 mDecodedSize;
-		BOOL mNeedsAux;
-		U32 mCacheHandle;
-		LLPointer<LLImageFormatted> mFormattedImage;
-		LLPointer<LLImageRaw> mRawImage;
-		e_curl_state mCurlState;
-		S32 mCurlReceivedSize;
-		LLCore::HttpHandle mHttpHandle;
-
-		FetchEntry() :
-			mDecodedLevel(-1),
-			mFetchedSize(0),
-			mDecodedSize(0),
-			mHttpHandle(LLCORE_HTTP_HANDLE_INVALID)
-			{}
-		FetchEntry(LLUUID& id, S32 r_size, /*S32 f_discard, S32 c,*/ S32 level, S32 f_size, S32 d_size) :
-			mID(id),
-			mRequestedSize(r_size),
-			mDecodedLevel(level),
-			mFetchedSize(f_size),
-			mDecodedSize(d_size),
-			mNeedsAux(false),
-			mHttpHandle(LLCORE_HTTP_HANDLE_INVALID)
-			{}
-	};
-	typedef std::vector<FetchEntry> fetch_list_t;
-	fetch_list_t mFetchingHistory;
-
-	typedef std::map<LLCore::HttpHandle, S32> handle_fetch_map_t;
-	handle_fetch_map_t mHandleToFetchIndex;
-
-	void setDebuggerState(e_debug_state new_state) { mDebuggerState = new_state; }
-	e_debug_state mDebuggerState;
-	
-	F32 mCacheReadTime;
-	F32 mCacheWriteTime;
-	F32 mDecodingTime;
-	F32 mHTTPTime;
-	F32 mGLCreationTime;
-
-	F32 mTotalFetchingTime;
-	F32 mRefetchVisCacheTime;
-	F32 mRefetchVisHTTPTime;
-	F32 mRefetchAllCacheTime;
-	F32 mRefetchAllHTTPTime;
-
-	LLTimer mTimer;
-	
-	LLTextureFetch* mFetcher;
-	LLTextureCache* mTextureCache;
-	LLImageDecodeThread* mImageDecodeThread;
-	LLCore::HttpHeaders::ptr_t mHttpHeaders;
-	LLCore::HttpRequest::policy_t mHttpPolicyClass;
-	
-	S32 mNumFetchedTextures;
-	S32 mNumCacheHits;
-	S32 mNumVisibleFetchedTextures;
-	S32 mNumVisibleFetchingRequests;
-	U32 mFetchedData;
-	U32 mDecodedData;
-	U32 mVisibleFetchedData;
-	U32 mVisibleDecodedData;
-	U32 mRenderedData;
-	U32 mRenderedDecodedData;
-	U32 mFetchedPixels;
-	U32 mRenderedPixels;
-	U32 mRefetchedVisData;
-	U32 mRefetchedVisPixels;
-	U32 mRefetchedAllData;
-	U32 mRefetchedAllPixels;
-
-	BOOL mFreezeHistory;
-	BOOL mStopDebug;
-	BOOL mClearHistory;
-	BOOL mRefetchNonVis;
-
-	std::string mHTTPUrl;
-	S32 mNbCurlRequests;
-	S32 mNbCurlCompleted;
-
-	std::map< LLPointer<LLViewerFetchedTexture>, std::vector<S32> > mRefetchList; // treats UI textures as normal textures
-	std::vector< LLPointer<LLViewerFetchedTexture> > mTempTexList;
-	S32 mTempIndex;
-	S32 mHistoryListIndex;
-
-public:
-	bool update(F32 max_time); //called in the main thread once per frame
-
-	//fetching history
-	void clearHistory();
-	void addHistoryEntry(LLTextureFetchWorker* worker);
-	
-	// Inherited from LLCore::HttpHandler
-	// Threads:  Ttf
-	virtual void onCompleted(LLCore::HttpHandle handle, LLCore::HttpResponse * response);
-
-	void startWork(e_debug_state state);
-	void setStopDebug() {mStopDebug = TRUE;}
-	void tryToStopDebug(); //stop everything
-	void callbackCacheRead(S32 id, bool success, LLImageFormatted* image,
-						   S32 imagesize, BOOL islocal);
-	void callbackCacheWrite(S32 id, bool success);
-	void callbackDecoded(S32 id, bool success, LLImageRaw* raw, LLImageRaw* aux);
-	void callbackHTTP(FetchEntry & fetch, LLCore::HttpResponse * response);
-
-	e_debug_state getState()             {return mDebuggerState;}
-	S32  getNumFetchedTextures()         {return mNumFetchedTextures;}
-	S32  getNumFetchingRequests()        {return mFetchingHistory.size();}
-	S32  getNumCacheHits()               {return mNumCacheHits;}
-	S32  getNumVisibleFetchedTextures()  {return mNumVisibleFetchedTextures;}
-	S32  getNumVisibleFetchingRequests() {return mNumVisibleFetchingRequests;}
-	U32  getFetchedData()                {return mFetchedData;}
-	U32  getDecodedData()                {return mDecodedData;}
-	U32  getVisibleFetchedData()         {return mVisibleFetchedData;}
-	U32  getVisibleDecodedData()         {return mVisibleDecodedData;}
-	U32  getRenderedData()               {return mRenderedData;}
-	U32  getRenderedDecodedData()        {return mRenderedDecodedData;}
-	U32  getFetchedPixels()              {return mFetchedPixels;}
-	U32  getRenderedPixels()             {return mRenderedPixels;}
-	U32  getRefetchedVisData()              {return mRefetchedVisData;}
-	U32  getRefetchedVisPixels()            {return mRefetchedVisPixels;}
-	U32  getRefetchedAllData()              {return mRefetchedAllData;}
-	U32  getRefetchedAllPixels()            {return mRefetchedAllPixels;}
-
-	F32  getCacheReadTime()     {return mCacheReadTime;}
-	F32  getCacheWriteTime()    {return mCacheWriteTime;}
-	F32  getDecodeTime()        {return mDecodingTime;}
-	F32  getGLCreationTime()    {return mGLCreationTime;}
-	F32  getHTTPTime()          {return mHTTPTime;}
-	F32  getTotalFetchingTime() {return mTotalFetchingTime;}
-	F32  getRefetchVisCacheTime() {return mRefetchVisCacheTime;}
-	F32  getRefetchVisHTTPTime()  {return mRefetchVisHTTPTime;}
-	F32  getRefetchAllCacheTime() {return mRefetchAllCacheTime;}
-	F32  getRefetchAllHTTPTime()  {return mRefetchAllHTTPTime;}
-
-private:
-	void init();
-	void clearTextures();//clear fetching results of all textures.
-	void clearCache();
-	void makeRefetchList();
-	void scanRefetchList();
-
-	void lockFetcher();
-	void unlockFetcher();
-
-	void lockCache();
-	void unlockCache();
-
-	void lockDecoder();
-	void unlockDecoder();
-	
-	S32 fillCurlQueue();
-
-	void startDebug();
-	void debugCacheRead();
-	void debugCacheWrite();	
-	void debugHTTP();
-	void debugDecoder();
-	void debugGLTextureCreation();
-	void debugRefetchVisibleFromCache();
-	void debugRefetchVisibleFromHTTP();
-	void debugRefetchAllFromCache();
-	void debugRefetchAllFromHTTP();
-
-	bool processStartDebug(F32 max_time);
-	bool processGLCreation(F32 max_time);
-
-private:
-	static bool sDebuggerEnabled;
-public:
-	static bool isEnabled() {return sDebuggerEnabled;}
-};
-
 
 class LLTextureFetchTester : public LLMetricPerformanceTesterBasic
 {
diff --git a/indra/newview/lltextureview.cpp b/indra/newview/lltextureview.cpp
index b74577315e..f0e9cee101 100644
--- a/indra/newview/lltextureview.cpp
+++ b/indra/newview/lltextureview.cpp
@@ -49,6 +49,8 @@
 #include "llviewerobjectlist.h"
 #include "llviewertexture.h"
 #include "llviewertexturelist.h"
+#include "llviewerwindow.h"
+#include "llwindow.h"
 #include "llvovolume.h"
 #include "llviewerstats.h"
 #include "llworld.h"
@@ -117,8 +119,8 @@ public:
 			LLTextureBar* bar2p = (LLTextureBar*)i2;
 			LLViewerFetchedTexture *i1p = bar1p->mImagep;
 			LLViewerFetchedTexture *i2p = bar2p->mImagep;
-			F32 pri1 = i1p->getDecodePriority(); // i1p->mRequestedDownloadPriority
-			F32 pri2 = i2p->getDecodePriority(); // i2p->mRequestedDownloadPriority
+			F32 pri1 = i1p->getMaxVirtualSize();
+			F32 pri2 = i2p->getMaxVirtualSize();
 			if (pri1 > pri2)
 				return true;
 			else if (pri2 > pri1)
@@ -177,7 +179,7 @@ void LLTextureBar::draw()
 	{
 		color = LLColor4::magenta; // except none and alm
 	}
-	else if (mImagep->getDecodePriority() <= 0.0f)
+	else if (mImagep->getMaxVirtualSize() <= 0.0f)
 	{
 		color = LLColor4::grey; color[VALPHA] = .7f;
 	}
@@ -202,26 +204,13 @@ void LLTextureBar::draw()
 	std::string uuid_str;
 	mImagep->mID.toString(uuid_str);
 	uuid_str = uuid_str.substr(0,7);
-	if (mTextureView->mOrderFetch)
-	{
-		tex_str = llformat("%s %7.0f %d(%d) 0x%08x(%8.0f)",
-						   uuid_str.c_str(),
-						   mImagep->mMaxVirtualSize,
-						   mImagep->mDesiredDiscardLevel,
-						   mImagep->mRequestedDiscardLevel,
-						   mImagep->mFetchPriority,
-						   mImagep->getDecodePriority());
-	}
-	else
-	{
-		tex_str = llformat("%s %7.0f %d(%d) %8.0f(0x%08x)",
-						   uuid_str.c_str(),
-						   mImagep->mMaxVirtualSize,
-						   mImagep->mDesiredDiscardLevel,
-						   mImagep->mRequestedDiscardLevel,
-						   mImagep->getDecodePriority(),
-						   mImagep->mFetchPriority);
-	}
+	
+    tex_str = llformat("%s %7.0f %d(%d)",
+        uuid_str.c_str(),
+        mImagep->mMaxVirtualSize,
+        mImagep->mDesiredDiscardLevel,
+        mImagep->mRequestedDiscardLevel);
+
 
 	LLFontGL::getFontMonospace()->renderUTF8(tex_str, 0, title_x1, getRect().getHeight(),
 									 color, LLFontGL::LEFT, LLFontGL::TOP);
@@ -500,10 +489,6 @@ private:
 
 void LLGLTexMemBar::draw()
 {
-	S32Megabytes bound_mem = LLViewerTexture::sBoundTextureMemory;
- 	S32Megabytes max_bound_mem = LLViewerTexture::sMaxBoundTextureMemory;
-	S32Megabytes total_mem = LLViewerTexture::sTotalTextureMemory;
-	S32Megabytes max_total_mem = LLViewerTexture::sMaxTotalTextureMem;
 	F32 discard_bias = LLViewerTexture::sDesiredDiscardBias;
 	F32 cache_usage = LLAppViewer::getTextureCache()->getUsage().valueInUnits<LLUnits::Megabytes>();
 	F32 cache_max_usage = LLAppViewer::getTextureCache()->getMaxUsage().valueInUnits<LLUnits::Megabytes>();
@@ -549,15 +534,10 @@ void LLGLTexMemBar::draw()
     U32 texFetchLatMed = U32(recording.getMean(LLTextureFetch::sTexFetchLatency).value() * 1000.0f);
     U32 texFetchLatMax = U32(recording.getMax(LLTextureFetch::sTexFetchLatency).value() * 1000.0f);
 
-	text = llformat("GL Tot: %d/%d MB GL Free: %d Sys Free: %d MB Bound: %4d/%4d MB FBO: %d MB Raw Tot: %d MB Bias: %.2f Cache: %.1f/%.1f MB",
-					total_mem.value(),
-					max_total_mem.value(),
-                    LLImageGLThread::getFreeVRAMMegabytes(),
+    text = llformat("GL Free: %d MB Sys Free: %d MB FBO: %d MB Bias: %.2f Cache: %.1f/%.1f MB",
+                    gViewerWindow->getWindow()->getAvailableVRAMMegabytes(),
                     LLMemory::getAvailableMemKB()/1024,
-					bound_mem.value(),
-					max_bound_mem.value(),
 					LLRenderTarget::sBytesAllocated/(1024*1024),
-					LLImageRaw::sGlobalRawMemory >> 20,
 					discard_bias,
 					cache_usage,
 					cache_max_usage);
@@ -837,7 +817,7 @@ void LLTextureView::draw()
 				LL_INFOS() << imagep->getID()
 						<< "\t" << tex_mem
 						<< "\t" << imagep->getBoostLevel()
-						<< "\t" << imagep->getDecodePriority()
+						<< "\t" << imagep->getMaxVirtualSize()
 						<< "\t" << imagep->getWidth()
 						<< "\t" << imagep->getHeight()
 						<< "\t" << cur_discard
@@ -857,7 +837,7 @@ void LLTextureView::draw()
 			}
 			else
 			{
-				pri = imagep->getDecodePriority();
+				pri = imagep->getMaxVirtualSize();
 			}
 			pri = llclamp(pri, 0.0f, HIGH_PRIORITY-1.f);
 			
diff --git a/indra/newview/llviewercontrol.cpp b/indra/newview/llviewercontrol.cpp
index d5f842d925..9682945208 100644
--- a/indra/newview/llviewercontrol.cpp
+++ b/indra/newview/llviewercontrol.cpp
@@ -341,12 +341,6 @@ static bool handleMaxPartCountChanged(const LLSD& newvalue)
 	return true;
 }
 
-static bool handleVideoMemoryChanged(const LLSD& newvalue)
-{
-	gTextureList.updateMaxResidentTexMem(S32Megabytes(newvalue.asInteger()));
-	return true;
-}
-
 static bool handleChatFontSizeChanged(const LLSD& newvalue)
 {
 	if(gConsole)
@@ -706,7 +700,6 @@ void settings_setup_listeners()
 	gSavedSettings.getControl("RenderShadowDetail")->getSignal()->connect(boost::bind(&handleSetShaderChanged, _2));
 	gSavedSettings.getControl("RenderDeferredSSAO")->getSignal()->connect(boost::bind(&handleSetShaderChanged, _2));
 	gSavedSettings.getControl("RenderPerformanceTest")->getSignal()->connect(boost::bind(&handleRenderPerfTestChanged, _2));
-	gSavedSettings.getControl("TextureMemory")->getSignal()->connect(boost::bind(&handleVideoMemoryChanged, _2));
 	gSavedSettings.getControl("ChatFontSize")->getSignal()->connect(boost::bind(&handleChatFontSizeChanged, _2));
 	gSavedSettings.getControl("ChatPersistTime")->getSignal()->connect(boost::bind(&handleChatPersistTimeChanged, _2));
 	gSavedSettings.getControl("ConsoleMaxLines")->getSignal()->connect(boost::bind(&handleConsoleMaxLinesChanged, _2));
diff --git a/indra/newview/llviewerdisplay.cpp b/indra/newview/llviewerdisplay.cpp
index 6d98d9b10e..77b84c6789 100644
--- a/indra/newview/llviewerdisplay.cpp
+++ b/indra/newview/llviewerdisplay.cpp
@@ -797,8 +797,6 @@ void display(BOOL rebuild, F32 zoom_factor, int subfield, BOOL for_snapshot)
 				LLViewerTexture::updateClass();
 			}
 
-            LLImageGLThread::updateClass();
-
 			{
 				LL_RECORD_BLOCK_TIME(FTM_IMAGE_UPDATE_BUMP);
 				gBumpImageList.updateImages();  // must be called before gTextureList version so that it's textures are thrown out first.
diff --git a/indra/newview/llviewerfloaterreg.cpp b/indra/newview/llviewerfloaterreg.cpp
index 97cb8e2000..2daa919f5c 100644
--- a/indra/newview/llviewerfloaterreg.cpp
+++ b/indra/newview/llviewerfloaterreg.cpp
@@ -132,7 +132,6 @@
 #include "llfloatertelehub.h"
 #include "llfloatertestinspectors.h"
 #include "llfloatertestlistview.h"
-#include "llfloatertexturefetchdebugger.h"
 #include "llfloatertools.h"
 #include "llfloatertopobjects.h"
 #include "llfloatertos.h"
@@ -284,10 +283,6 @@ void LLViewerFloaterReg::registerFloaters()
 	
 	LLFloaterReg::add("mem_leaking", "floater_mem_leaking.xml", (LLFloaterBuildFunc)&LLFloaterReg::build<LLFloaterMemLeak>);
 
-	if(gSavedSettings.getBOOL("TextureFetchDebuggerEnabled"))
-	{
-		LLFloaterReg::add("tex_fetch_debugger", "floater_texture_fetch_debugger.xml", (LLFloaterBuildFunc)&LLFloaterReg::build<LLFloaterTextureFetchDebugger>);
-	}
 	LLFloaterReg::add("media_settings", "floater_media_settings.xml", (LLFloaterBuildFunc)&LLFloaterReg::build<LLFloaterMediaSettings>);	
 	LLFloaterReg::add("marketplace_listings", "floater_marketplace_listings.xml", (LLFloaterBuildFunc)&LLFloaterReg::build<LLFloaterMarketplaceListings>);
 	LLFloaterReg::add("marketplace_validation", "floater_marketplace_validation.xml", (LLFloaterBuildFunc)&LLFloaterReg::build<LLFloaterMarketplaceValidation>);
diff --git a/indra/newview/llviewermenu.cpp b/indra/newview/llviewermenu.cpp
index 6aa1c5fece..6d61193a56 100644
--- a/indra/newview/llviewermenu.cpp
+++ b/indra/newview/llviewermenu.cpp
@@ -2515,14 +2515,6 @@ class LLDevelopSetLoggingLevel : public view_listener_t
 	}
 };
 
-class LLDevelopTextureFetchDebugger : public view_listener_t
-{
-	bool handleEvent(const LLSD& userdata)
-	{
-		return gSavedSettings.getBOOL("TextureFetchDebuggerEnabled");
-	}
-};
-
 //////////////////
 // ADMIN MENU   //
 //////////////////
@@ -9471,8 +9463,6 @@ void initialize_menus()
 	view_listener_t::addMenu(new LLDevelopCheckLoggingLevel(), "Develop.CheckLoggingLevel");
 	view_listener_t::addMenu(new LLDevelopSetLoggingLevel(), "Develop.SetLoggingLevel");
 	
-	//Develop (Texture Fetch Debug Console)
-	view_listener_t::addMenu(new LLDevelopTextureFetchDebugger(), "Develop.SetTexFetchDebugger");
 	//Develop (clear cache immediately)
 	commit.add("Develop.ClearCache", boost::bind(&handle_cache_clear_immediately) );
     //Develop (override environment map)
diff --git a/indra/newview/llviewerstats.cpp b/indra/newview/llviewerstats.cpp
index 3385d317e6..796ff04a41 100644
--- a/indra/newview/llviewerstats.cpp
+++ b/indra/newview/llviewerstats.cpp
@@ -155,10 +155,7 @@ LLTrace::SampleStatHandle<LLUnit<F32, LLUnits::Percent> >
 static LLTrace::SampleStatHandle<bool> 
 							CHAT_BUBBLES("chatbubbles", "Chat Bubbles Enabled");
 
-LLTrace::SampleStatHandle<F64Megabytes >	GL_TEX_MEM("gltexmemstat"),
-															GL_BOUND_MEM("glboundmemstat"),
-															RAW_MEM("rawmemstat"),
-															FORMATTED_MEM("formattedmemstat");
+LLTrace::SampleStatHandle<F64Megabytes > FORMATTED_MEM("formattedmemstat");
 LLTrace::SampleStatHandle<F64Kilobytes >	DELTA_BANDWIDTH("deltabandwidth", "Increase/Decrease in bandwidth based on packet loss"),
 															MAX_BANDWIDTH("maxbandwidth", "Max bandwidth setting");
 
@@ -319,8 +316,6 @@ U32Bytes			gTotalTextureBytesPerBoostLevel[LLViewerTexture::MAX_GL_IMAGE_CATEGOR
 extern U32  gVisCompared;
 extern U32  gVisTested;
 
-LLFrameTimer gTextureTimer;
-
 void update_statistics()
 {
 	gTotalWorldData += gVLManager.getTotalBytes();
@@ -416,19 +411,6 @@ void update_statistics()
 	}
 }
 
-void update_texture_time()
-{
-	if (gTextureList.isPrioRequestsFetched())
-	{
-		gTextureTimer.pause();
-	}
-	else
-	{		
-		gTextureTimer.unpause();
-	}
-
-	record(LLStatViewer::TEXTURE_FETCH_TIME, gTextureTimer.getElapsedTimeF32());
-}
 /*
  * The sim-side LLSD is in newsim/llagentinfo.cpp:forwardViewerStats.
  *
diff --git a/indra/newview/llviewerstats.h b/indra/newview/llviewerstats.h
index 017c79b2e3..c21c06256e 100644
--- a/indra/newview/llviewerstats.h
+++ b/indra/newview/llviewerstats.h
@@ -191,10 +191,8 @@ extern LLTrace::SampleStatHandle<>		FPS_SAMPLE,
 
 extern LLTrace::SampleStatHandle<LLUnit<F32, LLUnits::Percent> > PACKETS_LOST_PERCENT;
 
-extern LLTrace::SampleStatHandle<F64Megabytes >	GL_TEX_MEM,
-																	GL_BOUND_MEM,
-																	RAW_MEM,
-																	FORMATTED_MEM;
+extern LLTrace::SampleStatHandle<F64Megabytes > FORMATTED_MEM;
+
 extern LLTrace::SampleStatHandle<F64Kilobytes >	DELTA_BANDWIDTH,
 																	MAX_BANDWIDTH;
 extern SimMeasurement<F64Milliseconds >	SIM_FRAME_TIME,
@@ -296,7 +294,6 @@ void update_statistics();
 void send_viewer_stats(bool include_preferences);
 void update_texture_time();
 
-extern LLFrameTimer gTextureTimer;
 extern U32Bytes	gTotalTextureData;
 extern U32Bytes  gTotalObjectData;
 extern U32Bytes  gTotalTextureBytesPerBoostLevel[] ;
diff --git a/indra/newview/llviewertexture.cpp b/indra/newview/llviewertexture.cpp
index c389d2122e..0c23214b52 100644
--- a/indra/newview/llviewertexture.cpp
+++ b/indra/newview/llviewertexture.cpp
@@ -58,6 +58,8 @@
 #include "llvovolume.h"
 #include "llviewermedia.h"
 #include "lltexturecache.h"
+#include "llviewerwindow.h"
+#include "llwindow.h"
 ///////////////////////////////////////////////////////////////////////////////
 
 // extern
@@ -76,6 +78,8 @@ LLPointer<LLViewerFetchedTexture> LLViewerFetchedTexture::sSmokeImagep = NULL;
 LLPointer<LLViewerFetchedTexture> LLViewerFetchedTexture::sFlatNormalImagep = NULL;
 LLViewerMediaTexture::media_map_t LLViewerMediaTexture::sMediaMap;
 LLTexturePipelineTester* LLViewerTextureManager::sTesterp = NULL;
+F32 LLViewerFetchedTexture::sMaxVirtualSize = F32_MAX/2.f;
+
 const std::string sTesterName("TextureTester");
 
 S32 LLViewerTexture::sImageCount = 0;
@@ -84,11 +88,6 @@ S32 LLViewerTexture::sAuxCount = 0;
 LLFrameTimer LLViewerTexture::sEvaluationTimer;
 F32 LLViewerTexture::sDesiredDiscardBias = 0.f;
 F32 LLViewerTexture::sDesiredDiscardScale = 1.1f;
-S32Bytes LLViewerTexture::sBoundTextureMemory;
-S32Bytes LLViewerTexture::sTotalTextureMemory;
-S32Megabytes LLViewerTexture::sMaxBoundTextureMemory;
-S32Megabytes LLViewerTexture::sMaxTotalTextureMem;
-S32Bytes LLViewerTexture::sMaxDesiredTextureMem;
 S8  LLViewerTexture::sCameraMovingDiscardBias = 0;
 F32 LLViewerTexture::sCameraMovingBias = 0.0f;
 S32 LLViewerTexture::sMaxSculptRez = 128; //max sculpt image size
@@ -471,11 +470,6 @@ void LLViewerTextureManager::cleanup()
 void LLViewerTexture::initClass()
 {
 	LLImageGL::sDefaultGLTexture = LLViewerFetchedTexture::sDefaultImagep->getGLTexture();
-	
-	if(gSavedSettings.getBOOL("TextureFetchDebuggerEnabled"))
-	{
-		sTexelPixelRatio = gSavedSettings.getF32("TexelPixelRatio");
-	}
 }
 
 // tuning params
@@ -500,7 +494,7 @@ bool LLViewerTexture::isMemoryForTextureLow()
     S32Megabytes physical;
     getGPUMemoryForTextures(gpu, physical);
 
-    return (gpu < MIN_FREE_TEXTURE_MEMORY) || (physical < MIN_FREE_MAIN_MEMORY);
+    return (gpu < MIN_FREE_TEXTURE_MEMORY); // || (physical < MIN_FREE_MAIN_MEMORY);
 }
 
 //static
@@ -514,7 +508,7 @@ bool LLViewerTexture::isMemoryForTextureSuficientlyFree()
     S32Megabytes physical;
     getGPUMemoryForTextures(gpu, physical);
 
-    return (gpu > DESIRED_FREE_TEXTURE_MEMORY) && (physical > DESIRED_FREE_MAIN_MEMORY);
+    return (gpu > DESIRED_FREE_TEXTURE_MEMORY); // && (physical > DESIRED_FREE_MAIN_MEMORY);
 }
 
 //static
@@ -535,9 +529,9 @@ void LLViewerTexture::getGPUMemoryForTextures(S32Megabytes &gpu, S32Megabytes &p
     timer.reset();
 
     {
-        gpu_res = (S32Megabytes) LLImageGLThread::getFreeVRAMMegabytes();
+        gpu_res = (S32Megabytes)gViewerWindow->getWindow()->getAvailableVRAMMegabytes();
         
-        //check main memory, only works for windows.
+        //check main memory, only works for windows and macos.
         LLMemory::updateMemoryInfo();
         physical_res = LLMemory::getAvailableMemKB();
 
@@ -560,27 +554,7 @@ void LLViewerTexture::updateClass()
 
 	LLViewerMediaTexture::updateClass();
 
-	sBoundTextureMemory = LLImageGL::sBoundTextureMemory;
-	sTotalTextureMemory = LLImageGL::sGlobalTextureMemory;
-	sMaxBoundTextureMemory = gTextureList.getMaxResidentTexMem();
-	sMaxTotalTextureMem = gTextureList.getMaxTotalTextureMem();
-	sMaxDesiredTextureMem = sMaxTotalTextureMem; //in Bytes, by default and when total used texture memory is small.
-
-	if (sBoundTextureMemory >= sMaxBoundTextureMemory ||
-		sTotalTextureMemory >= sMaxTotalTextureMem)
-	{
-		//when texture memory overflows, lower down the threshold to release the textures more aggressively.
-		sMaxDesiredTextureMem = llmin(sMaxDesiredTextureMem * 0.75f, F32Bytes(gMaxVideoRam));
-	
-		// If we are using more texture memory than we should,
-		// scale up the desired discard level
-		if (sEvaluationTimer.getElapsedTimeF32() > discard_delta_time)
-		{
-			sDesiredDiscardBias += discard_bias_delta;
-			sEvaluationTimer.reset();
-		}
-	}
-	else if(isMemoryForTextureLow())
+	if(isMemoryForTextureLow())
 	{
 		// Note: isMemoryForTextureLow() uses 1s delay, make sure we waited enough for it to recheck
 		if (sEvaluationTimer.getElapsedTimeF32() > GPU_MEMORY_CHECK_WAIT_TIME)
@@ -590,8 +564,6 @@ void LLViewerTexture::updateClass()
 		}
 	}
 	else if (sDesiredDiscardBias > 0.0f
-			 && sBoundTextureMemory < sMaxBoundTextureMemory * texmem_lower_bound_scale
-			 && sTotalTextureMemory < sMaxTotalTextureMem * texmem_lower_bound_scale
 			 && isMemoryForTextureSuficientlyFree())
 	{
 		// If we are using less texture memory than we should,
@@ -661,7 +633,6 @@ void LLViewerTexture::init(bool firstinit)
 	mMaxVirtualSize = 0.f;
 	mMaxVirtualSizeResetInterval = 1;
 	mMaxVirtualSizeResetCounter = mMaxVirtualSizeResetInterval;
-	mAdditionalDecodePriority = 0.f;	
 	mParcelMedia = NULL;
 	
 	memset(&mNumVolumes, 0, sizeof(U32)* LLRender::NUM_VOLUME_TEXTURE_CHANNELS);
@@ -689,6 +660,11 @@ void LLViewerTexture::cleanup()
 {
 	notifyAboutMissingAsset();
 
+    if (LLAppViewer::getTextureFetch())
+    {
+        LLAppViewer::getTextureFetch()->updateRequestPriority(mID, 0.f);
+    }
+
 	mFaceList[LLRender::DIFFUSE_MAP].clear();
 	mFaceList[LLRender::NORMAL_MAP].clear();
 	mFaceList[LLRender::SPECULAR_MAP].clear();
@@ -745,6 +721,12 @@ void LLViewerTexture::setBoostLevel(S32 level)
 		}
 	}
 
+    // strongly encourage anything boosted to load at full res
+    if (mBoostLevel >= LLViewerTexture::BOOST_HIGH)
+    {
+        mMaxVirtualSize = 2048.f * 2048.f;
+    }
+
 	if (mBoostLevel == LLViewerTexture::BOOST_SELECTED)
 	{
 		mSelectedTime = gFrameTimeSeconds;
@@ -828,15 +810,8 @@ void LLViewerTexture::addTextureStats(F32 virtual_size, BOOL needs_gltexture) co
 	}
 
 	virtual_size *= sTexelPixelRatio;
-	if(!mMaxVirtualSizeResetCounter)
-	{
-		//flag to reset the values because the old values are used.
-		resetMaxVirtualSizeResetCounter();
-		mMaxVirtualSize = virtual_size;
-		mAdditionalDecodePriority = 0.f;
-		mNeedsGLTexture = needs_gltexture;
-	}
-	else if (virtual_size > mMaxVirtualSize)
+
+	if (virtual_size > mMaxVirtualSize)
 	{
 		mMaxVirtualSize = virtual_size;
 	}
@@ -845,7 +820,6 @@ void LLViewerTexture::addTextureStats(F32 virtual_size, BOOL needs_gltexture) co
 void LLViewerTexture::resetTextureStats()
 {
 	mMaxVirtualSize = 0.0f;
-	mAdditionalDecodePriority = 0.f;	
 	mMaxVirtualSizeResetCounter = 0;
 }
 
@@ -1114,7 +1088,6 @@ void LLViewerFetchedTexture::init(bool firstinit)
 
 	if (firstinit)
 	{
-		mDecodePriority = 0.f;
 		mInImageList = 0;
 	}
 
@@ -1163,6 +1136,7 @@ void LLViewerFetchedTexture::init(bool firstinit)
 
 LLViewerFetchedTexture::~LLViewerFetchedTexture()
 {
+    assert_main_thread();
 	//*NOTE getTextureFetch can return NULL when Viewer is shutting down.
 	// This is due to LLWearableList is singleton and is destroyed after 
 	// LLAppViewer::cleanup() was called. (see ticket EXT-177)
@@ -1359,10 +1333,7 @@ void LLViewerFetchedTexture::dump()
 void LLViewerFetchedTexture::destroyTexture() 
 {
     LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
-	if(LLImageGL::sGlobalTextureMemory < sMaxDesiredTextureMem * 0.95f)//not ready to release unused memory.
-	{
-		return ;
-	}
+
 	if (mNeedsCreateTexture)//return if in the process of generating a new texture.
 	{
 		return;
@@ -1598,6 +1569,7 @@ BOOL LLViewerFetchedTexture::createTexture(S32 usename/*= 0*/)
 
 void LLViewerFetchedTexture::postCreateTexture()
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
     if (!mNeedsCreateTexture)
     {
         return;
@@ -1621,6 +1593,8 @@ void LLViewerFetchedTexture::postCreateTexture()
 
 void LLViewerFetchedTexture::scheduleCreateTexture()
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
+
     if (!mNeedsCreateTexture)
     {
         mNeedsCreateTexture = TRUE;
@@ -1697,6 +1671,7 @@ void LLViewerFetchedTexture::scheduleCreateTexture()
 //virtual
 void LLViewerFetchedTexture::setKnownDrawSize(S32 width, S32 height)
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	if(mKnownDrawWidth < width || mKnownDrawHeight < height)
 	{
 		mKnownDrawWidth = llmax(mKnownDrawWidth, width);
@@ -1708,9 +1683,31 @@ void LLViewerFetchedTexture::setKnownDrawSize(S32 width, S32 height)
 	addTextureStats((F32)(mKnownDrawWidth * mKnownDrawHeight));
 }
 
+void LLViewerFetchedTexture::setDebugText(const std::string& text)
+{
+    for (U32 ch = 0; ch < LLRender::NUM_TEXTURE_CHANNELS; ++ch)
+    {
+        llassert(mNumFaces[ch] <= mFaceList[ch].size());
+
+        for (U32 i = 0; i < mNumFaces[ch]; i++)
+        {
+            LLFace* facep = mFaceList[ch][i];
+            if (facep)
+            {
+                LLDrawable* drawable = facep->getDrawable();
+                if (drawable)
+                {
+                    drawable->getVObj()->setDebugText(text);
+                }
+            }
+        }
+    }
+}
+
 //virtual
 void LLViewerFetchedTexture::processTextureStats()
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	if(mFullyLoaded)
 	{		
 		if(mDesiredDiscardLevel > mMinDesiredDiscardLevel)//need to load more
@@ -1718,6 +1715,7 @@ void LLViewerFetchedTexture::processTextureStats()
 			mDesiredDiscardLevel = llmin(mDesiredDiscardLevel, mMinDesiredDiscardLevel);
 			mFullyLoaded = FALSE;
 		}
+        //setDebugText("fully loaded");
 	}
 	else
 	{
@@ -1730,7 +1728,7 @@ void LLViewerFetchedTexture::processTextureStats()
 			mDesiredDiscardLevel = 0;
 		}
 		else if (!LLPipeline::sRenderDeferred && mBoostLevel == LLGLTexture::BOOST_ALM)
-		{
+		{ // ??? don't load spec and normal maps when alm is disabled ???
 			mDesiredDiscardLevel = MAX_DISCARD_LEVEL + 1;
 		}
         else if (mDontDiscard && mBoostLevel == LLGLTexture::BOOST_ICON)
@@ -1788,198 +1786,8 @@ void LLViewerFetchedTexture::processTextureStats()
 	}
 }
 
-const F32 MAX_PRIORITY_PIXEL                         = 999.f;     //pixel area
-const F32 PRIORITY_BOOST_LEVEL_FACTOR                = 1000.f;    //boost level
-const F32 PRIORITY_DELTA_DISCARD_LEVEL_FACTOR        = 100000.f;  //delta discard
-const S32 MAX_DELTA_DISCARD_LEVEL_FOR_PRIORITY       = 4;
-const F32 PRIORITY_ADDITIONAL_FACTOR                 = 1000000.f; //additional 
-const S32 MAX_ADDITIONAL_LEVEL_FOR_PRIORITY          = 8;
-const F32 PRIORITY_BOOST_HIGH_FACTOR                 = 10000000.f;//boost high
-F32 LLViewerFetchedTexture::calcDecodePriority()
-{
-#ifndef LL_RELEASE_FOR_DOWNLOAD
-	if (mID == LLAppViewer::getTextureFetch()->mDebugID)
-	{
-		LLAppViewer::getTextureFetch()->mDebugCount++; // for setting breakpoints
-	}
-#endif
-	
-	if (mNeedsCreateTexture)
-	{
-		return mDecodePriority; // no change while waiting to create
-	}
-	if(mFullyLoaded && !mForceToSaveRawImage)//already loaded for static texture
-	{
-		return -1.0f; //alreay fetched
-	}
-
-	S32 cur_discard = getCurrentDiscardLevelForFetching();
-	bool have_all_data = (cur_discard >= 0 && (cur_discard <= mDesiredDiscardLevel));
-	F32 pixel_priority = (F32) sqrt(mMaxVirtualSize);
-
-	F32 priority = 0.f;
-
-	if (mIsMissingAsset)
-	{
-		priority = 0.0f;
-	}
-	else if(mDesiredDiscardLevel >= cur_discard && cur_discard > -1)
-	{
-		priority = -2.0f;
-	}
-	else if(mCachedRawDiscardLevel > -1 && mDesiredDiscardLevel >= mCachedRawDiscardLevel)
-	{
-		priority = -3.0f;
-	}
-	else if (mDesiredDiscardLevel > getMaxDiscardLevel())
-	{
-		// Don't decode anything we don't need
-		priority = -4.0f;
-	}
-	else if ((mBoostLevel == LLGLTexture::BOOST_UI || mBoostLevel == LLGLTexture::BOOST_ICON) && !have_all_data)
-	{
-		priority = 1.f;
-	}
-	else if (pixel_priority < 0.001f && !have_all_data)
-	{
-		// Not on screen but we might want some data
-		if (mBoostLevel > BOOST_SELECTED)
-		{
-			// Always want high boosted images
-			priority = 1.f;
-		}
-		else
-		{
-			priority = -5.f; //stop fetching
-		}
-	}
-	else if (cur_discard < 0)
-	{
-		//texture does not have any data, so we don't know the size of the image, treat it like 32 * 32.
-		// priority range = 100,000 - 500,000
-		static const F64 log_2 = log(2.0);
-		F32 desired = (F32)(log(32.0/pixel_priority) / log_2);
-		S32 ddiscard = MAX_DISCARD_LEVEL - (S32)desired;
-		ddiscard = llclamp(ddiscard, 0, MAX_DELTA_DISCARD_LEVEL_FOR_PRIORITY);
-		priority = (ddiscard + 1) * PRIORITY_DELTA_DISCARD_LEVEL_FACTOR;
-		setAdditionalDecodePriority(0.1f);//boost the textures without any data so far.
-	}
-	else if ((mMinDiscardLevel > 0) && (cur_discard <= mMinDiscardLevel))
-	{
-		// larger mips are corrupted
-		priority = -6.0f;
-	}
-	else
-	{
-		// priority range = 100,000 - 500,000
-		S32 desired_discard = mDesiredDiscardLevel;
-		if (!isJustBound() && mCachedRawImageReady)
-		{
-			if(mBoostLevel < BOOST_HIGH)
-			{
-				// We haven't rendered this in a while, de-prioritize it
-				desired_discard += 2;
-			}
-			else
-			{
-				// We haven't rendered this in the last half second, and we have a cached raw image, leave the desired discard as-is
-				desired_discard = cur_discard;
-			}
-		}
-
-		S32 ddiscard = cur_discard - desired_discard;
-		ddiscard = llclamp(ddiscard, -1, MAX_DELTA_DISCARD_LEVEL_FOR_PRIORITY);
-		priority = (ddiscard + 1) * PRIORITY_DELTA_DISCARD_LEVEL_FACTOR;		
-	}
-
-	// Priority Formula:
-	// BOOST_HIGH  +  ADDITIONAL PRI + DELTA DISCARD + BOOST LEVEL + PIXELS
-	// [10,000,000] + [1,000,000-9,000,000]  + [100,000-500,000]   + [1-20,000]  + [0-999]
-	if (priority > 0.0f)
-	{
-		bool large_enough = mCachedRawImageReady && ((S32)mTexelsPerImage > sMinLargeImageSize);
-		if(large_enough)
-		{
-			//Note: 
-			//to give small, low-priority textures some chance to be fetched, 
-			//cut the priority in half if the texture size is larger than 256 * 256 and has a 64*64 ready.
-			priority *= 0.5f; 
-		}
-
-		pixel_priority = llclamp(pixel_priority, 0.0f, MAX_PRIORITY_PIXEL); 
-
-		priority += pixel_priority + PRIORITY_BOOST_LEVEL_FACTOR * mBoostLevel;
-
-		if ( mBoostLevel > BOOST_HIGH)
-		{
-			if(mBoostLevel > BOOST_SUPER_HIGH)
-			{
-				//for very important textures, always grant the highest priority.
-				priority += PRIORITY_BOOST_HIGH_FACTOR;
-			}
-			else if(mCachedRawImageReady)
-			{
-				//Note: 
-				//to give small, low-priority textures some chance to be fetched, 
-				//if high priority texture has a 64*64 ready, lower its fetching priority.
-				setAdditionalDecodePriority(0.5f);
-			}
-			else
-			{
-				priority += PRIORITY_BOOST_HIGH_FACTOR;
-			}
-		}		
-
-		if(mAdditionalDecodePriority > 0.0f)
-		{
-			// priority range += 1,000,000.f-9,000,000.f
-			F32 additional = PRIORITY_ADDITIONAL_FACTOR * (1.0 + mAdditionalDecodePriority * MAX_ADDITIONAL_LEVEL_FOR_PRIORITY);
-			if(large_enough)
-			{
-				//Note: 
-				//to give small, low-priority textures some chance to be fetched, 
-				//cut the additional priority to a quarter if the texture size is larger than 256 * 256 and has a 64*64 ready.
-				additional *= 0.25f;
-			}
-			priority += additional;
-		}
-	}
-	return priority;
-}
-
-//static
-F32 LLViewerFetchedTexture::maxDecodePriority()
-{
-	static const F32 max_priority = PRIORITY_BOOST_HIGH_FACTOR +                           //boost_high
-		PRIORITY_ADDITIONAL_FACTOR * (MAX_ADDITIONAL_LEVEL_FOR_PRIORITY + 1) +             //additional (view dependent factors)
-		PRIORITY_DELTA_DISCARD_LEVEL_FACTOR * (MAX_DELTA_DISCARD_LEVEL_FOR_PRIORITY + 1) + //delta discard
-		PRIORITY_BOOST_LEVEL_FACTOR * (BOOST_MAX_LEVEL - 1) +                              //boost level
-		MAX_PRIORITY_PIXEL + 1.0f;                                                        //pixel area.
-	
-	return max_priority;
-}
-
 //============================================================================
 
-void LLViewerFetchedTexture::setDecodePriority(F32 priority)
-{
-	mDecodePriority = priority;
-
-	if(mDecodePriority < F_ALMOST_ZERO)
-	{
-		mStopFetchingTimer.reset();
-	}
-}
-
-void LLViewerFetchedTexture::setAdditionalDecodePriority(F32 priority)
-{
-	priority = llclamp(priority, 0.f, 1.f);
-	if(mAdditionalDecodePriority < priority)
-	{
-		mAdditionalDecodePriority = priority;
-	}
-}
-
 void LLViewerFetchedTexture::updateVirtualSize() 
 {	
     LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
@@ -1988,6 +1796,18 @@ void LLViewerFetchedTexture::updateVirtualSize()
 		addTextureStats(0.f, FALSE);//reset
 	}
 
+    if (getBoostLevel() >= LLViewerTexture::BOOST_HIGH)
+    { //always load boosted textures at highest priority full res
+        addTextureStats(sMaxVirtualSize);
+        return;
+    }
+
+    if (sDesiredDiscardBias > 0.f)
+    {
+        // running out of video memory, don't hold onto high res textures in the background
+        mMaxVirtualSize = 0.f;
+    }
+
 	for (U32 ch = 0; ch < LLRender::NUM_TEXTURE_CHANNELS; ++ch)
 	{				
 		llassert(mNumFaces[ch] <= mFaceList[ch].size());
@@ -2009,8 +1829,12 @@ void LLViewerFetchedTexture::updateVirtualSize()
 						setBoostLevel(LLViewerTexture::BOOST_SELECTED);
 					}
 					addTextureStats(facep->getVirtualSize());
-					setAdditionalDecodePriority(facep->getImportanceToCamera());
+                    //drawable->getVObj()->setDebugText(llformat("%d:%d", (S32)sqrtf(facep->getVirtualSize()), (S32)sqrtf(getMaxVirtualSize())));
 				}
+                else
+                {
+                    //drawable->getVObj()->setDebugText("");
+                }
 			}
 		}
 	}
@@ -2072,6 +1896,16 @@ bool LLViewerFetchedTexture::isActiveFetching()
 	return mFetchState > 7 && mFetchState < 10 && monitor_enabled; //in state of WAIT_HTTP_REQ or DECODE_IMAGE.
 }
 
+void LLViewerFetchedTexture::setBoostLevel(S32 level)
+{
+    LLViewerTexture::setBoostLevel(level);
+
+    if (level >= LLViewerTexture::BOOST_HIGH)
+    {
+        mDesiredDiscardLevel = 0;
+    }
+}
+
 bool LLViewerFetchedTexture::updateFetch()
 {
     LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
@@ -2098,31 +1932,40 @@ bool LLViewerFetchedTexture::updateFetch()
 
 	if (mNeedsCreateTexture)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("vftuf - needs create");
 		// We may be fetching still (e.g. waiting on write)
 		// but don't check until we've processed the raw data we have
 		return false;
 	}
 	if (mIsMissingAsset)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("vftuf - missing asset");
 		llassert_always(!mHasFetcher);
 		return false; // skip
 	}
 	if (!mLoadedCallbackList.empty() && mRawImage.notNull())
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("vftuf - callback pending");
 		return false; // process any raw image data in callbacks before replacing
 	}
 	if(mInFastCacheList)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("vftuf - in fast cache");
 		return false;
 	}
+    if (mGLTexturep.isNull())
+    { // fix for crash inside getCurrentDiscardLevelForFetching (shouldn't happen but appears to be happening)
+        llassert(false);
+        return false;
+    }
 	
 	S32 current_discard = getCurrentDiscardLevelForFetching();
 	S32 desired_discard = getDesiredDiscardLevel();
-	F32 decode_priority = getDecodePriority();
-	decode_priority = llclamp(decode_priority, 0.0f, maxDecodePriority());
+	F32 decode_priority = mMaxVirtualSize;
 
 	if (mIsFetching)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("vftuf - is fetching");
 		// Sets mRawDiscardLevel, mRawImage, mAuxRawImage
 		S32 fetch_discard = current_discard;
 		
@@ -2140,17 +1983,25 @@ bool LLViewerFetchedTexture::updateFetch()
 		if (finished)
 		{
 			mIsFetching = FALSE;
+            mLastFetchState = -1;
+            setDebugText("");
 			mLastPacketTimer.reset();
 		}
 		else
 		{
 			mFetchState = LLAppViewer::getTextureFetch()->getFetchState(mID, mDownloadProgress, mRequestedDownloadPriority,
 																		mFetchPriority, mFetchDeltaTime, mRequestDeltaTime, mCanUseHTTP);
+            /*if (mFetchState != mLastFetchState)
+            {
+                setDebugText(LLTextureFetch::getStateString(mFetchState));
+                mLastFetchState = mFetchState;
+            }*/
 		}
 		
 		// We may have data ready regardless of whether or not we are finished (e.g. waiting on write)
 		if (mRawImage.notNull())
 		{
+            LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("vftuf - has raw image");
 			LLTexturePipelineTester* tester = (LLTexturePipelineTester*)LLMetricPerformanceTesterBasic::getTester(sTesterName);
 			if (tester)
 			{
@@ -2161,6 +2012,7 @@ bool LLViewerFetchedTexture::updateFetch()
 			if ((mRawImage->getDataSize() > 0 && mRawDiscardLevel >= 0) &&
 				(current_discard < 0 || mRawDiscardLevel < current_discard))
 			{
+                LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("vftuf - data good");
 				mFullWidth = mRawImage->getWidth() << mRawDiscardLevel;
 				mFullHeight = mRawImage->getHeight() << mRawDiscardLevel;
 				setTexelsPerImage();
@@ -2197,6 +2049,7 @@ bool LLViewerFetchedTexture::updateFetch()
 			}
 			else
 			{
+                LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("vftuf - data not needed");
 				// Data is ready but we don't need it
 				// (received it already while fetcher was writing to disk)
 				destroyRawImage();
@@ -2206,7 +2059,7 @@ bool LLViewerFetchedTexture::updateFetch()
 		
 		if (!mIsFetching)
 		{
-			if ((decode_priority > 0) && (mRawDiscardLevel < 0 || mRawDiscardLevel == INVALID_DISCARD_LEVEL))
+			if ((decode_priority > 0) && (mRawDiscardLevel < 0))
 			{
 				// We finished but received no data
 				if (getDiscardLevel() < 0)
@@ -2229,13 +2082,13 @@ bool LLViewerFetchedTexture::updateFetch()
 					if(current_discard >= 0)
 					{
 						mMinDiscardLevel = current_discard;
-						desired_discard = current_discard;
+						//desired_discard = current_discard;
 					}
 					else
 					{
 						S32 dis_level = getDiscardLevel();
 						mMinDiscardLevel = dis_level;
-						desired_discard = dis_level;
+						//desired_discard = dis_level;
 					}
 				}
 				destroyRawImage();
@@ -2249,12 +2102,6 @@ bool LLViewerFetchedTexture::updateFetch()
 		}
 		else
 		{
-// 			// Useful debugging code for undesired deprioritization of textures.
-// 			if (decode_priority <= 0.0f && desired_discard >= 0 && desired_discard < current_discard)
-// 			{
-// 				LL_INFOS() << "Calling updateRequestPriority() with decode_priority = 0.0f" << LL_ENDL;
-// 				calcDecodePriority();
-// 			}
 			static const F32 MAX_HOLD_TIME = 5.0f; //seconds to wait before canceling fecthing if decode_priority is 0.f.
 			if(decode_priority > 0.0f || mStopFetchingTimer.getElapsedTimeF32() > MAX_HOLD_TIME)
 			{
@@ -2264,21 +2111,27 @@ bool LLViewerFetchedTexture::updateFetch()
 		}
 	}
 
+    desired_discard = llmin(desired_discard, getMaxDiscardLevel());
+
 	bool make_request = true;	
-	if (decode_priority <= 0)
+	/*if (decode_priority <= 0)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("vftuf - priority <= 0");
 		make_request = false;
 	}
 	else if(mDesiredDiscardLevel > getMaxDiscardLevel())
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("vftuf - desired > max");
 		make_request = false;
 	}
-	else if (mNeedsCreateTexture || mIsMissingAsset)
+	else */ if (mNeedsCreateTexture || mIsMissingAsset)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("vftuf - create or missing");
 		make_request = false;
 	}
 	else if (current_discard >= 0 && current_discard <= mMinDiscardLevel)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("vftuf - current < min");
 		make_request = false;
 	}
 	else if(mCachedRawImage.notNull() // can be empty
@@ -2295,6 +2148,7 @@ bool LLViewerFetchedTexture::updateFetch()
 	
 	if (make_request)
 	{
+#if 0
 		// Load the texture progressively: we try not to rush to the desired discard too fast.
 		// If the camera is not moving, we do not tweak the discard level notch by notch but go to the desired discard with larger boosted steps
 		// This mitigates the "textures stay blurry" problem when loading while not killing the texture memory while moving around
@@ -2311,18 +2165,23 @@ bool LLViewerFetchedTexture::updateFetch()
         {
 			desired_discard = llmax(desired_discard, current_discard - delta_level);
         }
+#endif
 
 		if (mIsFetching)
 		{
+            // already requested a higher resolution mip
 			if (mRequestedDiscardLevel <= desired_discard)
 			{
+                LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("vftuf - requested < desired");
 				make_request = false;
 			}
 		}
 		else
 		{
+            // already at a higher resolution mip, don't discard
 			if (current_discard >= 0 && current_discard <= desired_discard)
 			{
+                LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("vftuf - current <= desired");
 				make_request = false;
 			}
 		}
@@ -2330,6 +2189,7 @@ bool LLViewerFetchedTexture::updateFetch()
 	
 	if (make_request)
 	{
+        LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("vftuf - make request");
 		S32 w=0, h=0, c=0;
 		if (getDiscardLevel() >= 0)
 		{
@@ -2351,6 +2211,7 @@ bool LLViewerFetchedTexture::updateFetch()
 		
 		if (fetch_request_created)
 		{
+            LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("vftuf - request created");
 			mHasFetcher = TRUE;
 			mIsFetching = TRUE;
 			mRequestedDiscardLevel = desired_discard;
@@ -2358,15 +2219,18 @@ bool LLViewerFetchedTexture::updateFetch()
 													   mFetchPriority, mFetchDeltaTime, mRequestDeltaTime, mCanUseHTTP);
 		}
 
-		// if createRequest() failed, we're finishing up a request for this UUID,
-		// wait for it to complete
+        // If createRequest() failed, that means one of two things:
+        // 1. We're finishing up a request for this UUID, so we
+        //    should wait for it to complete
+        // 2. We've failed a request for this UUID, so there is
+        //    no need to create another request
 	}
 	else if (mHasFetcher && !mIsFetching)
 	{
 		// Only delete requests that haven't received any network data
 		// for a while.  Note - this is the normal mechanism for
 		// deleting requests, not just a place to handle timeouts.
-		const F32 FETCH_IDLE_TIME = 5.f;
+		const F32 FETCH_IDLE_TIME = 0.1f;
 		if (mLastPacketTimer.getElapsedTimeF32() > FETCH_IDLE_TIME)
 		{
  			LL_DEBUGS("Texture") << "exceeded idle time " << FETCH_IDLE_TIME << ", deleting request: " << getID() << LL_ENDL;
@@ -2676,7 +2540,7 @@ bool LLViewerFetchedTexture::doLoadedCallbacks()
 			LL_INFOS() << "baked texture: " << mID << "clears all call backs due to inactivity." << LL_ENDL;
 			LL_INFOS() << mUrl << LL_ENDL;
 			LL_INFOS() << "current discard: " << getDiscardLevel() << " current discard for fetch: " << getCurrentDiscardLevelForFetching() <<
-				" Desired discard: " << getDesiredDiscardLevel() << "decode Pri: " << getDecodePriority() << LL_ENDL;
+				" Desired discard: " << getDesiredDiscardLevel() << "decode Pri: " << mMaxVirtualSize << LL_ENDL;
 		}
 
 		clearCallbackEntryList() ; //remove all callbacks.
@@ -2907,7 +2771,7 @@ void LLViewerFetchedTexture::forceImmediateUpdate()
 		return;
 	}
 	//if already called forceImmediateUpdate()
-	if(mInImageList && mDecodePriority == LLViewerFetchedTexture::maxDecodePriority())
+	if(mInImageList && mMaxVirtualSize == LLViewerFetchedTexture::sMaxVirtualSize)
 	{
 		return;
 	}
@@ -2976,6 +2840,7 @@ bool LLViewerFetchedTexture::needsToSaveRawImage()
 
 void LLViewerFetchedTexture::destroyRawImage()
 {	
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	if (mAuxRawImage.notNull() && !needsToSaveRawImage())
 	{
 		sAuxCount--;
@@ -3059,6 +2924,7 @@ void LLViewerFetchedTexture::setCachedRawImage(S32 discard_level, LLImageRaw* im
 
 void LLViewerFetchedTexture::setCachedRawImage()
 {	
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	if(mRawImage == mCachedRawImage)
 	{
 		return;
@@ -3134,6 +3000,7 @@ void LLViewerFetchedTexture::checkCachedRawSculptImage()
 
 void LLViewerFetchedTexture::saveRawImage() 
 {
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	if(mRawImage.isNull() || mRawImage == mSavedRawImage || (mSavedRawDiscardLevel >= 0 && mSavedRawDiscardLevel <= mRawDiscardLevel))
 	{
 		return;
@@ -3349,25 +3216,10 @@ void LLViewerLODTexture::processTextureStats()
 		}
 		else
 		{
-			if(isLargeImage() && !isJustBound() && mAdditionalDecodePriority < 0.3f)
-			{
-				//if is a big image and not being used recently, nor close to the view point, do not load hi-res data.
-				mMaxVirtualSize = llmin(mMaxVirtualSize, (F32)LLViewerTexture::sMinLargeImageSize);
-			}
-
-			if ((mCalculatedDiscardLevel >= 0.f) &&
-				(llabs(mMaxVirtualSize - mDiscardVirtualSize) < mMaxVirtualSize*.20f))
-			{
-				// < 20% change in virtual size = no change in desired discard
-				discard_level = mCalculatedDiscardLevel; 
-			}
-			else
-			{
-				// Calculate the required scale factor of the image using pixels per texel
-				discard_level = (F32)(log(mTexelsPerImage/mMaxVirtualSize) / log_4);
-				mDiscardVirtualSize = mMaxVirtualSize;
-				mCalculatedDiscardLevel = discard_level;
-			}
+			// Calculate the required scale factor of the image using pixels per texel
+			discard_level = (F32)(log(mTexelsPerImage/mMaxVirtualSize) / log_4);
+			mDiscardVirtualSize = mMaxVirtualSize;
+			mCalculatedDiscardLevel = discard_level;
 		}
 		if (mBoostLevel < LLGLTexture::BOOST_SCULPTED)
 		{
@@ -3407,18 +3259,6 @@ void LLViewerLODTexture::processTextureStats()
 				//needs to release texture memory urgently
 				scaleDown();
 			}
-			// Limit the amount of GL memory bound each frame
-			else if ( sBoundTextureMemory > sMaxBoundTextureMemory * texmem_middle_bound_scale &&
-				(!getBoundRecently() || mDesiredDiscardLevel >= mCachedRawDiscardLevel))
-			{
-				scaleDown();
-			}
-			// Only allow GL to have 2x the video card memory
-			else if ( sTotalTextureMemory > sMaxTotalTextureMem * texmem_middle_bound_scale &&
-				(!getBoundRecently() || mDesiredDiscardLevel >= mCachedRawDiscardLevel))
-			{
-				scaleDown();
-			}
 		}
 
 		if (isUpdateFrozen() // we are out of memory and nearing max allowed bias
@@ -4199,7 +4039,6 @@ void LLTexturePipelineTester::compareTestSessions(llofstream* os)
 	*os << llformat("%s\n", getTesterName().c_str());
 	*os << llformat("AggregateResults\n");
 
-	compareTestResults(os, "TotalFetchingTime", base_sessionp->mTotalFetchingTime, current_sessionp->mTotalFetchingTime);
 	compareTestResults(os, "TotalGrayTime", base_sessionp->mTotalGrayTime, current_sessionp->mTotalGrayTime);
 	compareTestResults(os, "TotalStablizingTime", base_sessionp->mTotalStablizingTime, current_sessionp->mTotalStablizingTime);
 	compareTestResults(os, "StartTimeLoadingSculpties", base_sessionp->mStartTimeLoadingSculpties, current_sessionp->mStartTimeLoadingSculpties);		
@@ -4259,7 +4098,6 @@ LLMetricPerformanceTesterWithSession::LLTestSession* LLTexturePipelineTester::lo
 		return NULL;
 	}
 	
-	F32 total_fetching_time = 0.f;
 	F32 total_gray_time = 0.f;
 	F32 total_stablizing_time = 0.f;
 	F32 total_loading_sculpties_time = 0.f;
@@ -4294,7 +4132,6 @@ LLMetricPerformanceTesterWithSession::LLTestSession* LLTexturePipelineTester::lo
 		F32 cur_time   = (*log)[label]["Time"].asReal();
 		if(start_time - start_fetching_time > F_ALMOST_ZERO) //fetching has paused for a while
 		{
-			sessionp->mTotalFetchingTime += total_fetching_time;
 			sessionp->mTotalGrayTime += total_gray_time;
 			sessionp->mTotalStablizingTime += total_stablizing_time;
 
@@ -4302,14 +4139,12 @@ LLMetricPerformanceTesterWithSession::LLTestSession* LLTexturePipelineTester::lo
 			sessionp->mTotalTimeLoadingSculpties += total_loading_sculpties_time;
 
 			start_fetching_time = start_time;
-			total_fetching_time = 0.0f;
 			total_gray_time = 0.f;
 			total_stablizing_time = 0.f;
 			total_loading_sculpties_time = 0.f;
 		}
 		else
 		{
-			total_fetching_time = cur_time - start_time;
 			total_gray_time = (*log)[label]["TotalGrayTime"].asReal();
 			total_stablizing_time = (*log)[label]["TotalStablizingTime"].asReal();
 
@@ -4355,7 +4190,6 @@ LLMetricPerformanceTesterWithSession::LLTestSession* LLTexturePipelineTester::lo
 		in_log = (*log).has(currentLabel);
 	}
 
-	sessionp->mTotalFetchingTime += total_fetching_time;
 	sessionp->mTotalGrayTime += total_gray_time;
 	sessionp->mTotalStablizingTime += total_stablizing_time;
 
@@ -4377,8 +4211,6 @@ LLTexturePipelineTester::LLTextureTestSession::~LLTextureTestSession()
 }
 void LLTexturePipelineTester::LLTextureTestSession::reset() 
 {
-	mTotalFetchingTime = 0.0f;
-
 	mTotalGrayTime = 0.0f;
 	mTotalStablizingTime = 0.0f;
 
diff --git a/indra/newview/llviewertexture.h b/indra/newview/llviewertexture.h
index 53cf911102..5893f549d0 100644
--- a/indra/newview/llviewertexture.h
+++ b/indra/newview/llviewertexture.h
@@ -134,7 +134,7 @@ public:
 	/*virtual*/ bool isActiveFetching();
 	
 	/*virtual*/ const LLUUID& getID() const { return mID; }
-	void setBoostLevel(S32 level);
+	virtual void setBoostLevel(S32 level);
 	S32  getBoostLevel() { return mBoostLevel; }
 	void setTextureListType(S32 tex_type) { mTextureListType = tex_type; }
 	S32 getTextureListType() { return mTextureListType; }
@@ -188,19 +188,20 @@ private:
 
 	virtual void switchToCachedImage();
 	
-	static bool isMemoryForTextureLow() ;
 	static bool isMemoryForTextureSuficientlyFree();
 	static void getGPUMemoryForTextures(S32Megabytes &gpu, S32Megabytes &physical);
 
+public:
+    static bool isMemoryForTextureLow();
 protected:
+    friend class LLViewerTextureList;
 	LLUUID mID;
 	S32 mTextureListType; // along with mID identifies where to search for this texture in TextureList
 
 	F32 mSelectedTime;				// time texture was last selected
-	mutable F32 mMaxVirtualSize;	// The largest virtual size of the image, in pixels - how much data to we need?	
-	mutable S32  mMaxVirtualSizeResetCounter ;
+	mutable F32 mMaxVirtualSize = 0.f;	// The largest virtual size of the image, in pixels - how much data to we need?	
+	mutable S32  mMaxVirtualSizeResetCounter;
 	mutable S32  mMaxVirtualSizeResetInterval;
-	mutable F32 mAdditionalDecodePriority;  // priority add to mDecodePriority.
 	LLFrameTimer mLastReferencedTimer;	
 
 	ll_face_list_t    mFaceList[LLRender::NUM_TEXTURE_CHANNELS]; //reverse pointer pointing to the faces using this image as texture
@@ -226,11 +227,6 @@ public:
 	static LLFrameTimer sEvaluationTimer;
 	static F32 sDesiredDiscardBias;
 	static F32 sDesiredDiscardScale;
-	static S32Bytes sBoundTextureMemory;
-	static S32Bytes sTotalTextureMemory;
-	static S32Megabytes sMaxBoundTextureMemory;
-	static S32Megabytes sMaxTotalTextureMem;
-	static S32Bytes sMaxDesiredTextureMem ;
 	static S8  sCameraMovingDiscardBias;
 	static F32 sCameraMovingBias;
 	static S32 sMaxSculptRez ;
@@ -285,7 +281,6 @@ public:
 	LLViewerFetchedTexture(const std::string& url, FTType f_type, const LLUUID& id, BOOL usemipmaps = TRUE);
 
 public:
-	static F32 maxDecodePriority();
 	
 	struct Compare
 	{
@@ -294,9 +289,10 @@ public:
 		{
 			const LLViewerFetchedTexture* lhsp = (const LLViewerFetchedTexture*)lhs;
 			const LLViewerFetchedTexture* rhsp = (const LLViewerFetchedTexture*)rhs;
+            
 			// greater priority is "less"
-			const F32 lpriority = lhsp->getDecodePriority();
-			const F32 rpriority = rhsp->getDecodePriority();
+			const F32 lpriority = lhsp->mMaxVirtualSize;
+			const F32 rpriority = rhsp->mMaxVirtualSize;
 			if (lpriority > rpriority) // higher priority
 				return true;
 			if (lpriority < rpriority)
@@ -306,10 +302,10 @@ public:
 	};
 
 public:
-	/*virtual*/ S8 getType() const ;
+	/*virtual*/ S8 getType() const override;
 	FTType getFTType() const;
-	/*virtual*/ void forceImmediateUpdate() ;
-	/*virtual*/ void dump() ;
+	/*virtual*/ void forceImmediateUpdate() override;
+	/*virtual*/ void dump() override;
 
 	// Set callbacks to get called when the image gets updated with higher 
 	// resolution versions.
@@ -335,7 +331,6 @@ public:
 	void destroyTexture() ;
 
 	virtual void processTextureStats() ;
-	F32  calcDecodePriority() ;
 
 	BOOL needsAux() const { return mNeedsAux; }
 
@@ -343,20 +338,12 @@ public:
 	void setTargetHost(LLHost host)			{ mTargetHost = host; }
 	LLHost getTargetHost() const			{ return mTargetHost; }
 	
-	// Set the decode priority for this image...
-	// DON'T CALL THIS UNLESS YOU KNOW WHAT YOU'RE DOING, it can mess up
-	// the priority list, and cause horrible things to happen.
-	void setDecodePriority(F32 priority = -1.0f);
-	F32 getDecodePriority() const { return mDecodePriority; };
-	F32 getAdditionalDecodePriority() const { return mAdditionalDecodePriority; };
-
-	void setAdditionalDecodePriority(F32 priority) ;
-	
 	void updateVirtualSize() ;
 
 	S32  getDesiredDiscardLevel()			 { return mDesiredDiscardLevel; }
 	void setMinDiscardLevel(S32 discard) 	{ mMinDesiredDiscardLevel = llmin(mMinDesiredDiscardLevel,(S8)discard); }
 
+    void setBoostLevel(S32 level) override;
 	bool updateFetch();
 	bool setDebugFetching(S32 debug_level);
 	bool isInDebug() const { return mInDebug; }
@@ -369,10 +356,14 @@ public:
 	// Override the computation of discard levels if we know the exact output
 	// size of the image.  Used for UI textures to not decode, even if we have
 	// more data.
-	/*virtual*/ void setKnownDrawSize(S32 width, S32 height);
+	/*virtual*/ void setKnownDrawSize(S32 width, S32 height) override;
+
+    // Set the debug text of all Viewer Objects associated with this texture
+    // to the specified text
+    void setDebugText(const std::string& text);
 
 	void setIsMissingAsset(BOOL is_missing = true);
-	/*virtual*/ BOOL isMissingAsset() const { return mIsMissingAsset; }
+	/*virtual*/ BOOL isMissingAsset() const override { return mIsMissingAsset; }
 
 	// returns dimensions of original image for local files (before power of two scaling)
 	// and returns 0 for all asset system images
@@ -415,7 +406,7 @@ public:
 	BOOL        isRawImageValid()const { return mIsRawImageValid ; }	
 	void        forceToSaveRawImage(S32 desired_discard = 0, F32 kept_time = 0.f) ;
 	void        forceToRefetchTexture(S32 desired_discard = 0, F32 kept_time = 60.f);
-	/*virtual*/ void setCachedRawImage(S32 discard_level, LLImageRaw* imageraw) ;
+	/*virtual*/ void setCachedRawImage(S32 discard_level, LLImageRaw* imageraw) override;
 	void        destroySavedRawImage() ;
 	LLImageRaw* getSavedRawImage() ;
 	BOOL        hasSavedRawImage() const ;
@@ -431,10 +422,10 @@ public:
 	void        setInFastCacheList(bool in_list) { mInFastCacheList = in_list; }
 	bool        isInFastCacheList() { return mInFastCacheList; }
 
-	/*virtual*/bool  isActiveFetching(); //is actively in fetching by the fetching pipeline.
+	/*virtual*/bool  isActiveFetching() override; //is actively in fetching by the fetching pipeline.
 
 protected:
-	/*virtual*/ void switchToCachedImage();
+	/*virtual*/ void switchToCachedImage() override;
 	S32 getCurrentDiscardLevelForFetching() ;
 
 private:
@@ -472,11 +463,11 @@ protected:
 	S32 mRequestedDiscardLevel;
 	F32 mRequestedDownloadPriority;
 	S32 mFetchState;
+    S32 mLastFetchState = -1; // DEBUG
 	U32 mFetchPriority;
 	F32 mDownloadProgress;
 	F32 mFetchDeltaTime;
 	F32 mRequestDeltaTime;
-	F32 mDecodePriority;			// The priority for decoding this image.
 	S32	mMinDiscardLevel;
 	S8  mDesiredDiscardLevel;			// The discard level we'd LIKE to have - if we have it and there's space	
 	S8  mMinDesiredDiscardLevel;	// The minimum discard level we'd like to have
@@ -500,7 +491,7 @@ protected:
 	F32             mLastCallBackActiveTime;
 
 	LLPointer<LLImageRaw> mRawImage;
-	S32 mRawDiscardLevel;
+	S32 mRawDiscardLevel = -1;
 
 	// Used ONLY for cloth meshes right now.  Make SURE you know what you're 
 	// doing if you use it for anything else! - djs
@@ -534,6 +525,7 @@ protected:
 	BOOL   mIsFetched ; //is loaded from remote or from cache, not generated locally.
 
 public:
+    static F32 sMaxVirtualSize; //maximum possible value of mMaxVirtualSize
 	static LLPointer<LLViewerFetchedTexture> sMissingAssetImagep;	// Texture to show for an image asset that is not in the database
 	static LLPointer<LLViewerFetchedTexture> sWhiteImagep;	// Texture to show NOTHING (whiteness)
 	static LLPointer<LLViewerFetchedTexture> sDefaultImagep; // "Default" texture for error cases, the only case of fetched texture which is generated in local.
@@ -774,7 +766,6 @@ private:
 
 		void reset() ;
 
-		F32 mTotalFetchingTime ;
 		F32 mTotalGrayTime ;
 		F32 mTotalStablizingTime ;
 		F32 mStartTimeLoadingSculpties ; 
diff --git a/indra/newview/llviewertexturelist.cpp b/indra/newview/llviewertexturelist.cpp
index bbbf9ea7a3..1a766dd404 100644
--- a/indra/newview/llviewertexturelist.cpp
+++ b/indra/newview/llviewertexturelist.cpp
@@ -89,8 +89,6 @@ LLTextureKey::LLTextureKey(LLUUID id, ETexListType tex_type)
 
 LLViewerTextureList::LLViewerTextureList() 
 	: mForceResetTextureStats(FALSE),
-	mMaxResidentTexMemInMegaBytes(0),
-	mMaxTotalTextureMemInMegaBytes(0),
 	mInitialized(FALSE)
 {
 }
@@ -99,12 +97,6 @@ void LLViewerTextureList::init()
 {			
 	mInitialized = TRUE ;
 	sNumImages = 0;
-	mMaxResidentTexMemInMegaBytes = (U32Bytes)0;
-	mMaxTotalTextureMemInMegaBytes = (U32Bytes)0;
-	
-	// Update how much texture RAM we're allowed to use.
-	updateMaxResidentTexMem(S32Megabytes(0)); // 0 = use current
-	
 	doPreloadImages();
 }
 
@@ -204,10 +196,8 @@ static std::string get_texture_list_name()
 void LLViewerTextureList::doPrefetchImages()
 {
     LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
-	gTextureTimer.start();
-	gTextureTimer.pause();
 
-	if (LLAppViewer::instance()->getPurgeCache())
+    if (LLAppViewer::instance()->getPurgeCache())
 	{
 		// cache was purged, no point
 		return;
@@ -342,7 +332,7 @@ void LLViewerTextureList::dump()
 	{
 		LLViewerFetchedTexture* image = *it;
 
-		LL_INFOS() << "priority " << image->getDecodePriority()
+		LL_INFOS() << "priority " << image->getMaxVirtualSize()
 		<< " boost " << image->getBoostLevel()
 		<< " size " << image->getWidth() << "x" << image->getHeight()
 		<< " discard " << image->getDiscardLevel()
@@ -667,13 +657,14 @@ void LLViewerTextureList::removeImageFromList(LLViewerFetchedTexture *image)
 	assert_main_thread();
 	llassert_always(mInitialized) ;
 	llassert(image);
+    image->validateRefCount();
 
 	S32 count = 0;
 	if (image->isInImageList())
 	{
 		count = mImageList.erase(image) ;
 		if(count != 1) 
-	{
+	    {
 			LL_INFOS() << "Image  " << image->getID() 
 				<< " had mInImageList set but mImageList.erase() returned " << count
 				<< LL_ENDL;
@@ -699,6 +690,7 @@ void LLViewerTextureList::removeImageFromList(LLViewerFetchedTexture *image)
 			LL_INFOS() << "Image  " << image->getID() << " was in mUUIDMap with same pointer" << LL_ENDL ;
 		}
 		count = mImageList.erase(image) ;
+        llassert(count != 0);
 		if(count != 0) 
 		{	// it was in the list already?
 			LL_WARNS() << "Image  " << image->getID() 
@@ -784,17 +776,12 @@ void LLViewerTextureList::updateImages(F32 max_time)
 		using namespace LLStatViewer;
 		sample(NUM_IMAGES, sNumImages);
 		sample(NUM_RAW_IMAGES, LLImageRaw::sRawImageCount);
-		sample(GL_TEX_MEM, LLImageGL::sGlobalTextureMemory);
-		sample(GL_BOUND_MEM, LLImageGL::sBoundTextureMemory);
-		sample(RAW_MEM, F64Bytes(LLImageRaw::sGlobalRawMemory));
 		sample(FORMATTED_MEM, F64Bytes(LLImageFormatted::sGlobalFormattedMemory));
 	}
 
 	//loading from fast cache 
 	max_time -= updateImagesLoadingFastCache(max_time);
 	
-	updateImagesDecodePriorities();
-	
     F32 total_max_time = max_time;
 
 	max_time -= updateImagesFetchTextures(max_time);
@@ -825,7 +812,6 @@ void LLViewerTextureList::updateImages(F32 max_time)
 			didone = image->doLoadedCallbacks();
 		}
 	}
-	
 
 	updateImagesUpdateStats();
 }
@@ -848,120 +834,78 @@ void LLViewerTextureList::clearFetchingRequests()
 	}
 }
 
-void LLViewerTextureList::updateImagesDecodePriorities()
+void LLViewerTextureList::updateImageDecodePriority(LLViewerFetchedTexture* imagep)
 {
-    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
-	// Update the decode priority for N images each frame
-	{
-		F32 lazy_flush_timeout = 30.f; // stop decoding
-		F32 max_inactive_time  = 20.f; // actually delete
-		S32 min_refs = 3; // 1 for mImageList, 1 for mUUIDMap, 1 for local reference
-
-		//reset imagep->getLastReferencedTimer() when screen is showing the progress view to avoid removing pre-fetched textures too soon.
-		bool reset_timer = gViewerWindow->getProgressView()->getVisible();
-        
-        static const S32 MAX_PRIO_UPDATES = gSavedSettings.getS32("TextureFetchUpdatePriorities");         // default: 32
-		const size_t max_update_count = llmin((S32) (MAX_PRIO_UPDATES*MAX_PRIO_UPDATES*gFrameIntervalSeconds.value()) + 1, MAX_PRIO_UPDATES);
-		S32 update_counter = llmin(max_update_count, mUUIDMap.size());
-		uuid_map_t::iterator iter = mUUIDMap.upper_bound(mLastUpdateKey);
-		while ((update_counter-- > 0) && !mUUIDMap.empty())
-		{
-			if (iter == mUUIDMap.end())
-			{
-				iter = mUUIDMap.begin();
+    if (imagep->isInDebug() || imagep->isUnremovable())
+    {
+        //update_counter--;
+        return; //is in debug, ignore.
+    }
+
+    F32 lazy_flush_timeout = 30.f; // stop decoding
+    F32 max_inactive_time = 20.f; // actually delete
+    S32 min_refs = 3; // 1 for mImageList, 1 for mUUIDMap, 1 for local reference
+
+    //
+    // Flush formatted images using a lazy flush
+    //
+    S32 num_refs = imagep->getNumRefs();
+    if (num_refs == min_refs)
+    {
+        if (imagep->getLastReferencedTimer()->getElapsedTimeF32() > lazy_flush_timeout)
+        {
+            // Remove the unused image from the image list
+            deleteImage(imagep);
+            imagep = NULL; // should destroy the image								
+        }
+        return;
+    }
+    else
+    {
+        if (imagep->hasSavedRawImage())
+        {
+            if (imagep->getElapsedLastReferencedSavedRawImageTime() > max_inactive_time)
+            {
+                imagep->destroySavedRawImage();
             }
-            mLastUpdateKey = iter->first;
-			LLPointer<LLViewerFetchedTexture> imagep = iter->second;
-			++iter; // safe to increment now
+        }
 
-			if(imagep->isInDebug() || imagep->isUnremovable())
-			{
-				update_counter--;
-				continue; //is in debug, ignore.
-			}
+        if (imagep->isDeleted())
+        {
+            return;
+        }
+        else if (imagep->isDeletionCandidate())
+        {
+            imagep->destroyTexture();
+            return;
+        }
+        else if (imagep->isInactive())
+        {
+            if (imagep->getLastReferencedTimer()->getElapsedTimeF32() > max_inactive_time)
+            {
+                imagep->setDeletionCandidate();
+            }
+            return;
+        }
+        else
+        {
+            imagep->getLastReferencedTimer()->reset();
 
-			//
-			// Flush formatted images using a lazy flush
-			//
-			S32 num_refs = imagep->getNumRefs();
-			if (num_refs == min_refs)
-			{
-				if(reset_timer)
-				{
-					imagep->getLastReferencedTimer()->reset();
-				}
-				else if (imagep->getLastReferencedTimer()->getElapsedTimeF32() > lazy_flush_timeout)
-				{
-					// Remove the unused image from the image list
-					deleteImage(imagep);
-					imagep = NULL; // should destroy the image								
-				}
-				continue;
-			}
-			else
-			{
-				if(imagep->hasSavedRawImage())
-				{
-					if(imagep->getElapsedLastReferencedSavedRawImageTime() > max_inactive_time)
-					{
-						imagep->destroySavedRawImage() ;
-					}
-				}
-
-				if(imagep->isDeleted())
-				{
-					continue ;
-				}
-				else if(imagep->isDeletionCandidate())
-				{
-					imagep->destroyTexture() ;																
-					continue ;
-				}
-				else if(imagep->isInactive())
-				{
-					if(reset_timer)
-					{
-						imagep->getLastReferencedTimer()->reset();
-					}
-					else if (imagep->getLastReferencedTimer()->getElapsedTimeF32() > max_inactive_time)
-					{
-						imagep->setDeletionCandidate() ;
-					}
-					continue ;
-				}
-				else
-				{
-					imagep->getLastReferencedTimer()->reset();
-
-					//reset texture state.
-					imagep->setInactive() ;										
-				}
-			}
+            //reset texture state.
+            imagep->setInactive();
+        }
+    }
 
-			if (!imagep->isInImageList())
-			{
-				continue;
-			}
-			if(imagep->isInFastCacheList())
-			{
-				continue; //wait for loading from the fast cache.
-			}
+    if (!imagep->isInImageList())
+    {
+        return;
+    }
+    if (imagep->isInFastCacheList())
+    {
+        return; //wait for loading from the fast cache.
+    }
 
-			imagep->processTextureStats();
-			F32 old_priority = imagep->getDecodePriority();
-			F32 old_priority_test = llmax(old_priority, 0.0f);
-			F32 decode_priority = imagep->calcDecodePriority();
-			F32 decode_priority_test = llmax(decode_priority, 0.0f);
-			// Ignore < 20% difference
-			if ((decode_priority_test < old_priority_test * .8f) ||
-				(decode_priority_test > old_priority_test * 1.25f))
-			{
-				mImageList.erase(imagep) ;
-				imagep->setDecodePriority(decode_priority);
-				mImageList.insert(imagep);
-			}
-		}
-	}
+    imagep->processTextureStats();
 }
 
 void LLViewerTextureList::setDebugFetching(LLViewerFetchedTexture* tex, S32 debug_level)
@@ -973,17 +917,9 @@ void LLViewerTextureList::setDebugFetching(LLViewerFetchedTexture* tex, S32 debu
 	}
 
 	const F32 DEBUG_PRIORITY = 100000.f;
-	F32 old_priority_test = llmax(tex->getDecodePriority(), 0.0f);
-	F32 decode_priority_test = DEBUG_PRIORITY;
-	
-	// Ignore < 20% difference
-	if ((decode_priority_test < old_priority_test * .8f) ||
-		(decode_priority_test > old_priority_test * 1.25f))
-	{
-		removeImageFromList(tex);
-		tex->setDecodePriority(decode_priority_test);
-		addImageToList(tex);
-	}
+	removeImageFromList(tex);
+    tex->mMaxVirtualSize = DEBUG_PRIORITY;
+	addImageToList(tex);
 }
 
 /*
@@ -1033,10 +969,6 @@ F32 LLViewerTextureList::updateImagesCreateTextures(F32 max_time)
 		LLViewerFetchedTexture *imagep = *curiter;
 		imagep->createTexture();
         imagep->postCreateTexture();
-		if (create_timer.getElapsedTimeF32() > max_time)
-		{
-			break;
-		}
 	}
 	mCreateTextureList.erase(mCreateTextureList.begin(), enditer);
 	return create_timer.getElapsedTimeF32();
@@ -1064,10 +996,6 @@ F32 LLViewerTextureList::updateImagesLoadingFastCache(F32 max_time)
 		enditer = iter;
 		LLViewerFetchedTexture *imagep = *curiter;
 		imagep->loadFromFastCache();
-		if (timer.getElapsedTimeF32() > max_time)
-		{
-			break;
-		}
 	}
 	mFastCacheList.erase(mFastCacheList.begin(), enditer);
 	return timer.getElapsedTimeF32();
@@ -1086,8 +1014,7 @@ void LLViewerTextureList::forceImmediateUpdate(LLViewerFetchedTexture* imagep)
 	}
 
 	imagep->processTextureStats();
-	F32 decode_priority = LLViewerFetchedTexture::maxDecodePriority() ;
-	imagep->setDecodePriority(decode_priority);
+    imagep->sMaxVirtualSize = LLViewerFetchedTexture::sMaxVirtualSize;
 	addImageToList(imagep);
 	
 	return ;
@@ -1096,76 +1023,55 @@ void LLViewerTextureList::forceImmediateUpdate(LLViewerFetchedTexture* imagep)
 F32 LLViewerTextureList::updateImagesFetchTextures(F32 max_time)
 {
     LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
-	LLTimer image_op_timer;
-	
-	// Update fetch for N images each frame
-	static const S32 MAX_HIGH_PRIO_COUNT = gSavedSettings.getS32("TextureFetchUpdateHighPriority");         // default: 32
-	static const S32 MAX_UPDATE_COUNT = gSavedSettings.getS32("TextureFetchUpdateMaxMediumPriority");       // default: 256
-	static const S32 MIN_UPDATE_COUNT = gSavedSettings.getS32("TextureFetchUpdateMinMediumPriority");       // default: 32
-	static const F32 MIN_PRIORITY_THRESHOLD = gSavedSettings.getF32("TextureFetchUpdatePriorityThreshold"); // default: 0.0
-	static const bool SKIP_LOW_PRIO = gSavedSettings.getBOOL("TextureFetchUpdateSkipLowPriority");          // default: false
-
-	size_t max_priority_count = llmin((S32) (MAX_HIGH_PRIO_COUNT*MAX_HIGH_PRIO_COUNT*gFrameIntervalSeconds.value())+1, MAX_HIGH_PRIO_COUNT);
-	max_priority_count = llmin(max_priority_count, mImageList.size());
-	
-	size_t total_update_count = mUUIDMap.size();
-	size_t max_update_count = llmin((S32) (MAX_UPDATE_COUNT*MAX_UPDATE_COUNT*gFrameIntervalSeconds.value())+1, MAX_UPDATE_COUNT);
-	max_update_count = llmin(max_update_count, total_update_count);	
-	
-	// MAX_HIGH_PRIO_COUNT high priority entries
-	typedef std::vector<LLViewerFetchedTexture*> entries_list_t;
-	entries_list_t entries;
-	size_t update_counter = max_priority_count;
-	image_priority_list_t::iterator iter1 = mImageList.begin();
-	while(update_counter > 0)
-	{
-		entries.push_back(*iter1);
-		
-		++iter1;
-		update_counter--;
-	}
-	
-	// MAX_UPDATE_COUNT cycled entries
-	update_counter = max_update_count;	
-	if(update_counter > 0)
-	{
-		uuid_map_t::iterator iter2 = mUUIDMap.upper_bound(mLastFetchKey);
-		while ((update_counter > 0) && (total_update_count > 0))
-		{
-			if (iter2 == mUUIDMap.end())
-			{
-				iter2 = mUUIDMap.begin();
-			}
-			LLViewerFetchedTexture* imagep = iter2->second;
-            // Skip the textures where there's really nothing to do so to give some times to others. Also skip the texture if it's already in the high prio set.
-            if (!SKIP_LOW_PRIO || (SKIP_LOW_PRIO && ((imagep->getDecodePriority() > MIN_PRIORITY_THRESHOLD) || imagep->hasFetcher())))
+    LLTimer image_op_timer;
+
+    typedef std::vector<LLPointer<LLViewerFetchedTexture> > entries_list_t;
+    entries_list_t entries;
+
+    // update N textures at beginning of mImageList
+    U32 update_count = 0;
+    static const S32 MIN_UPDATE_COUNT = gSavedSettings.getS32("TextureFetchUpdateMinCount");       // default: 32
+    // WIP -- dumb code here
+    //update MIN_UPDATE_COUNT or 10% of other textures, whichever is greater
+    update_count = llmax((U32) MIN_UPDATE_COUNT, (U32) mUUIDMap.size()/10);
+    update_count = llmin(update_count, (U32) mUUIDMap.size());
+    
+    {
+        LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("vtluift - copy");
+
+        // copy entries out of UUID map for updating
+        entries.reserve(update_count);
+        uuid_map_t::iterator iter = mUUIDMap.upper_bound(mLastUpdateKey);
+        while (update_count-- > 0)
+        {
+            if (iter == mUUIDMap.end())
             {
-                entries.push_back(imagep);
-                update_counter--;
+                iter = mUUIDMap.begin();
             }
+            
+            if (iter->second->getGLTexture())
+            {
+                entries.push_back(iter->second);
+            }
+            ++iter;
+        }
+    }
+
+    for (auto& imagep : entries)
+    {
+        if (imagep->getNumRefs() > 1) // make sure this image hasn't been deleted before attempting to update (may happen as a side effect of some other image updating)
+        {
+            updateImageDecodePriority(imagep);
+            imagep->updateFetch();
+        }
+    }
+
+    if (entries.size() > 0)
+    {
+        LLViewerFetchedTexture* imagep = *entries.rbegin();
+        mLastUpdateKey = LLTextureKey(imagep->getID(), (ETexListType)imagep->getTextureListType());
+    }
 
-			iter2++;
-			total_update_count--;
-		}
-	}
-	
-	S32 fetch_count = 0;
-	size_t min_update_count = llmin(MIN_UPDATE_COUNT,(S32)(entries.size()-max_priority_count));
-	S32 min_count = max_priority_count + min_update_count;
-	for (entries_list_t::iterator iter3 = entries.begin();
-		 iter3 != entries.end(); )
-	{
-		LLViewerFetchedTexture* imagep = *iter3++;
-		fetch_count += (imagep->updateFetch() ? 1 : 0);
-		if (min_count <= min_update_count)
-		{
-			mLastFetchKey = LLTextureKey(imagep->getID(), (ETexListType)imagep->getTextureListType());
-		}
-		if ((min_count-- <= 0) && (image_op_timer.getElapsedTimeF32() > max_time))
-		{
-			break;
-		}
-	}
 	return image_op_timer.getElapsedTimeF32();
 }
 
@@ -1209,8 +1115,6 @@ void LLViewerTextureList::decodeAllImages(F32 max_time)
 	{
 		LLViewerFetchedTexture* imagep = *iter;
 		imagep->processTextureStats();
-		F32 decode_priority = imagep->calcDecodePriority();
-		imagep->setDecodePriority(decode_priority);
 		addImageToList(imagep);
 	}
 	image_list.clear();
@@ -1349,156 +1253,6 @@ LLPointer<LLImageJ2C> LLViewerTextureList::convertToUploadFile(LLPointer<LLImage
 	return compressedImage;
 }
 
-// Returns min setting for TextureMemory (in MB)
-S32Megabytes LLViewerTextureList::getMinVideoRamSetting()
-{
-    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
-	U32Megabytes system_ram = gSysMemory.getPhysicalMemoryKB();
-	//min texture mem sets to 64M if total physical mem is more than 1.5GB
-	return (system_ram > U32Megabytes(1500)) ? S32Megabytes(64) : gMinVideoRam ;
-}
-
-//static
-// Returns max setting for TextureMemory (in MB)
-S32Megabytes LLViewerTextureList::getMaxVideoRamSetting(bool get_recommended, float mem_multiplier)
-{
-    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
-	S32Megabytes max_texmem;
-	if (gGLManager.mVRAM != 0)
-	{
-		// Treat any card with < 32 MB (shudder) as having 32 MB
-		//  - it's going to be swapping constantly regardless
-		S32Megabytes max_vram(gGLManager.mVRAM);
-
-		if(gGLManager.mIsAMD)
-		{
-			//shrink the availabe vram for ATI cards because some of them do not handel texture swapping well.
-			max_vram = max_vram * 0.75f; 
-		}
-
-		max_vram = llmax(max_vram, getMinVideoRamSetting());
-		max_texmem = max_vram;
-		if (!get_recommended)
-			max_texmem *= 2;
-	}
-	else
-	{
-		if (!get_recommended)
-		{
-			max_texmem = (S32Megabytes)512;
-		}
-		else if (gSavedSettings.getBOOL("NoHardwareProbe")) //did not do hardware detection at startup
-		{
-			max_texmem = (S32Megabytes)512;
-		}
-		else
-		{
-			max_texmem = (S32Megabytes)128;
-		}
-	}
-
-	S32Megabytes system_ram = gSysMemory.getPhysicalMemoryKB(); // In MB
-	//LL_INFOS() << "*** DETECTED " << system_ram << " MB of system memory." << LL_ENDL;
-	if (get_recommended)
-		max_texmem = llmin(max_texmem, system_ram/2);
-	else
-		max_texmem = llmin(max_texmem, system_ram);
-		
-    // limit the texture memory to a multiple of the default if we've found some cards to behave poorly otherwise
-	max_texmem = llmin(max_texmem, (S32Megabytes) (mem_multiplier * max_texmem));
-
-	max_texmem = llclamp(max_texmem, getMinVideoRamSetting(), gMaxVideoRam); 
-	
-	return max_texmem;
-}
-
-bool LLViewerTextureList::isPrioRequestsFetched()
-{
-	static LLCachedControl<F32> prio_threshold(gSavedSettings, "TextureFetchUpdatePriorityThreshold", 0.0f);
-	static LLCachedControl<F32> fetching_textures_threshold(gSavedSettings, "TextureListFetchingThreshold", 0.97f);
-	S32 fetching_tex_count = 0;
-	S32 tex_count_threshold = gTextureList.mImageList.size() * (1 - fetching_textures_threshold);
-
-	for (LLViewerTextureList::image_priority_list_t::iterator iter = gTextureList.mImageList.begin();
-		iter != gTextureList.mImageList.end(); )
-	{
-		LLPointer<LLViewerFetchedTexture> imagep = *iter++;
-		if (imagep->getDecodePriority() > prio_threshold)
-		{
-			if (imagep->hasFetcher() || imagep->isFetching())
-			{
-				fetching_tex_count++;
-				if (fetching_tex_count >= tex_count_threshold)
-				{
-					return false;
-				}
-			}
-		}
-	}
-
-	return true;
-}
-
-const S32Megabytes VIDEO_CARD_FRAMEBUFFER_MEM(12);
-const S32Megabytes MIN_MEM_FOR_NON_TEXTURE(512);
-void LLViewerTextureList::updateMaxResidentTexMem(S32Megabytes mem)
-{
-    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
-	// Initialize the image pipeline VRAM settings
-	S32Megabytes cur_mem(gSavedSettings.getS32("TextureMemory"));
-	F32 mem_multiplier = gSavedSettings.getF32("RenderTextureMemoryMultiple");
-	S32Megabytes default_mem = getMaxVideoRamSetting(true, mem_multiplier); // recommended default
-	if (mem == (S32Bytes)0)
-	{
-		mem = cur_mem > (S32Bytes)0 ? cur_mem : default_mem;
-	}
-	else if (mem < (S32Bytes)0)
-	{
-		mem = default_mem;
-	}
-
-	mem = llclamp(mem, getMinVideoRamSetting(), getMaxVideoRamSetting(false, mem_multiplier));
-	if (mem != cur_mem)
-	{
-		gSavedSettings.setS32("TextureMemory", mem.value());
-		return; //listener will re-enter this function
-	}
-
-	if (gGLManager.mVRAM == 0)
-	{
-		LL_WARNS() << "VRAM amount not detected, defaulting to " << mem << " MB" << LL_ENDL;
-	}
-
-	// TODO: set available resident texture mem based on use by other subsystems
-	// currently max(12MB, VRAM/4) assumed...
-	
-	S32Megabytes vb_mem = mem;
-	S32Megabytes fb_mem = llmax(VIDEO_CARD_FRAMEBUFFER_MEM, vb_mem/4);
-	mMaxResidentTexMemInMegaBytes = (vb_mem - fb_mem) ; //in MB
-	
-	mMaxTotalTextureMemInMegaBytes = mMaxResidentTexMemInMegaBytes * 2;
-	if (mMaxResidentTexMemInMegaBytes > (S32Megabytes)640)
-	{
-		mMaxTotalTextureMemInMegaBytes -= (mMaxResidentTexMemInMegaBytes / 4);
-	}
-
-	//system mem
-	S32Megabytes system_ram = gSysMemory.getPhysicalMemoryKB();
-
-	//minimum memory reserved for non-texture use.
-	//if system_raw >= 1GB, reserve at least 512MB for non-texture use;
-	//otherwise reserve half of the system_ram for non-texture use.
-	S32Megabytes min_non_texture_mem = llmin(system_ram / 2, MIN_MEM_FOR_NON_TEXTURE) ; 
-
-	if (mMaxTotalTextureMemInMegaBytes > system_ram - min_non_texture_mem)
-	{
-		mMaxTotalTextureMemInMegaBytes = system_ram - min_non_texture_mem ;
-	}
-	
-	LL_INFOS() << "Total Video Memory set to: " << vb_mem << " MB" << LL_ENDL;
-	LL_INFOS() << "Available Texture Memory set to: " << (vb_mem - fb_mem) << " MB" << LL_ENDL;
-}
-
 ///////////////////////////////////////////////////////////////////////////////
 
 // static
diff --git a/indra/newview/llviewertexturelist.h b/indra/newview/llviewertexturelist.h
index 99394e550c..cc6523c23e 100644
--- a/indra/newview/llviewertexturelist.h
+++ b/indra/newview/llviewertexturelist.h
@@ -124,25 +124,20 @@ public:
 
 	void handleIRCallback(void **data, const S32 number);
 
-	S32Megabytes	getMaxResidentTexMem() const	{ return mMaxResidentTexMemInMegaBytes; }
-	S32Megabytes getMaxTotalTextureMem() const   { return mMaxTotalTextureMemInMegaBytes;}
 	S32 getNumImages()					{ return mImageList.size(); }
 
-	void updateMaxResidentTexMem(S32Megabytes mem);
-	
 	void doPreloadImages();
 	void doPrefetchImages();
 
 	void clearFetchingRequests();
 	void setDebugFetching(LLViewerFetchedTexture* tex, S32 debug_level);
 
-	static S32Megabytes getMinVideoRamSetting();
-	static S32Megabytes getMaxVideoRamSetting(bool get_recommended, float mem_multiplier);
-
-	static bool isPrioRequestsFetched();
-	
 private:
-	void updateImagesDecodePriorities();
+    // do some book keeping on the specified texture
+    // - updates decode priority
+    // - updates desired discard level
+    // - cleans up textures that haven't been referenced in awhile
+    void updateImageDecodePriority(LLViewerFetchedTexture* imagep);
 	F32  updateImagesCreateTextures(F32 max_time);
 	F32  updateImagesFetchTextures(F32 max_time);
 	void updateImagesUpdateStats();
@@ -215,17 +210,14 @@ private:
     typedef std::map< LLTextureKey, LLPointer<LLViewerFetchedTexture> > uuid_map_t;
     uuid_map_t mUUIDMap;
     LLTextureKey mLastUpdateKey;
-    LLTextureKey mLastFetchKey;
 	
-	typedef std::set<LLPointer<LLViewerFetchedTexture>, LLViewerFetchedTexture::Compare> image_priority_list_t;	
+    typedef std::set < LLPointer<LLViewerFetchedTexture> > image_priority_list_t;
 	image_priority_list_t mImageList;
 
 	// simply holds on to LLViewerFetchedTexture references to stop them from being purged too soon
 	std::set<LLPointer<LLViewerFetchedTexture> > mImagePreloads;
 
 	BOOL mInitialized ;
-	S32Megabytes	mMaxResidentTexMemInMegaBytes;
-	S32Megabytes mMaxTotalTextureMemInMegaBytes;
 	LLFrameTimer mForceDecodeTimer;
 	
 private:
diff --git a/indra/newview/llviewerwindow.cpp b/indra/newview/llviewerwindow.cpp
index aa8d58cc8a..e9815a7872 100644
--- a/indra/newview/llviewerwindow.cpp
+++ b/indra/newview/llviewerwindow.cpp
@@ -493,24 +493,12 @@ public:
 		
 		if (gSavedSettings.getBOOL("DebugShowTime"))
 		{
-			{
-			const U32 y_inc2 = 15;
-				LLFrameTimer& timer = gTextureTimer;
-				F32 time = timer.getElapsedTimeF32();
-				S32 hours = (S32)(time / (60*60));
-				S32 mins = (S32)((time - hours*(60*60)) / 60);
-				S32 secs = (S32)((time - hours*(60*60) - mins*60));
-				addText(xpos, ypos, llformat("Texture: %d:%02d:%02d", hours,mins,secs)); ypos += y_inc2;
-			}
-			
-			{
 			F32 time = gFrameTimeSeconds;
 			S32 hours = (S32)(time / (60*60));
 			S32 mins = (S32)((time - hours*(60*60)) / 60);
 			S32 secs = (S32)((time - hours*(60*60) - mins*60));
 			addText(xpos, ypos, llformat("Time: %d:%02d:%02d", hours,mins,secs)); ypos += y_inc;
 		}
-		}
 		
 		if (gSavedSettings.getBOOL("DebugShowMemory"))
 		{
@@ -5640,7 +5628,6 @@ void LLViewerWindow::stopGL(BOOL save_state)
 
 		// Pause texture decode threads (will get unpaused during main loop)
 		LLAppViewer::getTextureCache()->pause();
-		LLAppViewer::getImageDecodeThread()->pause();
 		LLAppViewer::getTextureFetch()->pause();
 				
 		gSky.destroyGL();
@@ -5687,8 +5674,6 @@ void LLViewerWindow::stopGL(BOOL save_state)
 			LLGLSLShader* shader = *(LLGLSLShader::sInstances.begin());
 			shader->unload();
 		}
-		
-		LL_INFOS() << "Remaining allocated texture memory: " << LLImageGL::sGlobalTextureMemory.value() << " bytes" << LL_ENDL;
 	}
 }
 
diff --git a/indra/newview/llvoavatar.cpp b/indra/newview/llvoavatar.cpp
index e55ee21414..30e3d77d29 100644
--- a/indra/newview/llvoavatar.cpp
+++ b/indra/newview/llvoavatar.cpp
@@ -5707,7 +5707,6 @@ void LLVOAvatar::checkTextureLoading()
 }
 
 const F32  SELF_ADDITIONAL_PRI = 0.75f ;
-const F32  ADDITIONAL_PRI = 0.5f;
 void LLVOAvatar::addBakedTextureStats( LLViewerFetchedTexture* imagep, F32 pixel_area, F32 texel_area_ratio, S32 boost_level)
 {
 	//Note:
@@ -5722,15 +5721,6 @@ void LLVOAvatar::addBakedTextureStats( LLViewerFetchedTexture* imagep, F32 pixel
 	mMinPixelArea = llmin(pixel_area, mMinPixelArea);	
 	imagep->addTextureStats(pixel_area / texel_area_ratio);
 	imagep->setBoostLevel(boost_level);
-	
-	if(boost_level != LLGLTexture::BOOST_AVATAR_BAKED_SELF)
-	{
-		imagep->setAdditionalDecodePriority(ADDITIONAL_PRI) ;
-	}
-	else
-	{
-		imagep->setAdditionalDecodePriority(SELF_ADDITIONAL_PRI) ;
-	}
 }
 
 //virtual	
diff --git a/indra/newview/llvoavatarself.cpp b/indra/newview/llvoavatarself.cpp
index 60a69a4ac4..4080a61fb0 100644
--- a/indra/newview/llvoavatarself.cpp
+++ b/indra/newview/llvoavatarself.cpp
@@ -1825,7 +1825,7 @@ void LLVOAvatarSelf::dumpLocalTextures() const
 			}
 			else
 			{
-				const LLViewerFetchedTexture* image = dynamic_cast<LLViewerFetchedTexture*>( local_tex_obj->getImage() );
+				LLViewerFetchedTexture* image = dynamic_cast<LLViewerFetchedTexture*>( local_tex_obj->getImage() );
 
 				LL_INFOS() << "LocTex " << name << ": "
 						<< "Discard " << image->getDiscardLevel() << ", "
@@ -1835,7 +1835,7 @@ void LLVOAvatarSelf::dumpLocalTextures() const
 					// makes textures easier to steal
 						<< image->getID() << " "
 #endif
-						<< "Priority: " << image->getDecodePriority()
+						<< "Priority: " << image->getMaxVirtualSize()
 						<< LL_ENDL;
 			}
 		}
@@ -2074,8 +2074,7 @@ const std::string LLVOAvatarSelf::verboseDebugDumpLocalTextureDataInfo(const LLV
 									   << " glocdisc: " << getLocalDiscardLevel(tex_index, wearable_index)
 									   << " discard: " << image->getDiscardLevel()
 									   << " desired: " << image->getDesiredDiscardLevel()
-									   << " decode: " << image->getDecodePriority()
-									   << " addl: " << image->getAdditionalDecodePriority()
+									   << " vsize: " << image->getMaxVirtualSize()
 									   << " ts: " << image->getTextureState()
 									   << " bl: " << image->getBoostLevel()
 									   << " fl: " << image->isFullyLoaded() // this is not an accessor for mFullyLoaded - see comment there.
@@ -2453,7 +2452,6 @@ void LLVOAvatarSelf::addLocalTextureStats( ETextureIndex type, LLViewerFetchedTe
 				desired_pixels = llmin(mPixelArea, (F32)getTexImageArea());
 				
 				imagep->setBoostLevel(getAvatarBoostLevel());
-				imagep->setAdditionalDecodePriority(SELF_ADDITIONAL_PRI) ;
 				imagep->resetTextureStats();
 				imagep->setMaxVirtualSizeResetInterval(MAX_TEXTURE_VIRTUAL_SIZE_RESET_INTERVAL);
 				imagep->addTextureStats( desired_pixels / texel_area_ratio );
@@ -2823,7 +2821,6 @@ void LLVOAvatarSelf::deleteScratchTextures()
 		LL_DEBUGS() << "Clearing Scratch Textures " << (S32Kilobytes)sScratchTexBytes << LL_ENDL;
 
 		delete_and_clear(sScratchTexNames);
-		LLImageGL::sGlobalTextureMemory -= sScratchTexBytes;
 		sScratchTexBytes = S32Bytes(0);
 	}
 }
diff --git a/indra/newview/llvovolume.cpp b/indra/newview/llvovolume.cpp
index d654c470e2..ad11fb3908 100644
--- a/indra/newview/llvovolume.cpp
+++ b/indra/newview/llvovolume.cpp
@@ -696,12 +696,13 @@ void LLVOVolume::animateTextures()
 
 void LLVOVolume::updateTextures()
 {
-	const F32 TEXTURE_AREA_REFRESH_TIME = 5.f; // seconds
-	if (mTextureUpdateTimer.getElapsedTimeF32() > TEXTURE_AREA_REFRESH_TIME)
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
+	//const F32 TEXTURE_AREA_REFRESH_TIME = 1.f; // seconds
+	//if (mTextureUpdateTimer.getElapsedTimeF32() > TEXTURE_AREA_REFRESH_TIME)
 	{
 		updateTextureVirtualSize();
 
-		if (mDrawable.notNull() && !isVisible() && !mDrawable->isActive())
+		/*if (mDrawable.notNull() && !isVisible() && !mDrawable->isActive())
 		{ //delete vertex buffer to free up some VRAM
 			LLSpatialGroup* group  = mDrawable->getSpatialGroup();
 			if (group && (group->mVertexBuffer.notNull() || !group->mBufferMap.empty() || !group->mDrawMap.empty()))
@@ -712,9 +713,7 @@ void LLVOVolume::updateTextures()
 				//it becomes visible
 				group->setState(LLSpatialGroup::GEOM_DIRTY | LLSpatialGroup::MESH_DIRTY | LLSpatialGroup::NEW_DRAWINFO);
 			}
-		}
-
-
+		}*/
     }
 }
 
@@ -788,6 +787,7 @@ void LLVOVolume::updateTextureVirtualSize(bool forced)
 	const S32 num_faces = mDrawable->getNumFaces();
 	F32 min_vsize=999999999.f, max_vsize=0.f;
 	LLViewerCamera* camera = LLViewerCamera::getInstance();
+    std::stringstream debug_text;
 	for (S32 i = 0; i < num_faces; i++)
 	{
 		LLFace* face = mDrawable->getFace(i);
@@ -814,10 +814,14 @@ void LLVOVolume::updateTextureVirtualSize(bool forced)
 		else
 		{
 			vsize = face->getTextureVirtualSize();
+            imagep->addTextureStats(vsize);
 		}
 
-		mPixelArea = llmax(mPixelArea, face->getPixelArea());		
+		mPixelArea = llmax(mPixelArea, face->getPixelArea());
 
+        // if the face has gotten small enough to turn off texture animation and texture
+        // animation is running, rebuild the render batch for this face to turn off
+        // texture animation
 		if (face->mTextureMatrix != NULL)
 		{
 			if ((vsize < MIN_TEX_ANIM_SIZE && old_size > MIN_TEX_ANIM_SIZE) ||
@@ -837,10 +841,11 @@ void LLVOVolume::updateTextureVirtualSize(bool forced)
 			LLViewerFetchedTexture* img = LLViewerTextureManager::staticCastToFetchedTexture(imagep) ;
 			if(img)
 			{
-				F32 pri = img->getDecodePriority();
+                debug_text << img->getDiscardLevel() << ":" << img->getDesiredDiscardLevel() << ":" << img->getWidth() << ":" << (S32) sqrtf(vsize) << ":" << (S32) sqrtf(img->getMaxVirtualSize()) << "\n";
+				/*F32 pri = img->getDecodePriority();
 				pri = llmax(pri, 0.0f);
 				if (pri < min_vsize) min_vsize = pri;
-				if (pri > max_vsize) max_vsize = pri;
+				if (pri > max_vsize) max_vsize = pri;*/
 			}
 		}
 		else if (gPipeline.hasRenderDebugMask(LLPipeline::RENDER_DEBUG_FACE_AREA))
@@ -872,14 +877,6 @@ void LLVOVolume::updateTextureVirtualSize(bool forced)
 				F32 lodf = ((F32)(lod + 1.0f)/4.f);
 				F32 tex_size = lodf * LLViewerTexture::sMaxSculptRez ;
 				mSculptTexture->addTextureStats(2.f * tex_size * tex_size, FALSE);
-			
-				//if the sculpty very close to the view point, load first
-				{				
-					LLVector3 lookAt = getPositionAgent() - camera->getOrigin();
-					F32 dist = lookAt.normVec() ;
-					F32 cos_angle_to_view_dir = lookAt * camera->getXAxis() ;				
-					mSculptTexture->setAdditionalDecodePriority(0.8f * LLFace::calcImportanceToCamera(cos_angle_to_view_dir, dist)) ;
-				}
 			}
 	
 			S32 texture_discard = mSculptTexture->getCachedRawImageLevel(); //try to match the texture
@@ -923,7 +920,8 @@ void LLVOVolume::updateTextureVirtualSize(bool forced)
 	}
  	else if (gPipeline.hasRenderDebugMask(LLPipeline::RENDER_DEBUG_TEXTURE_PRIORITY))
  	{
- 		setDebugText(llformat("%.0f:%.0f", (F32) sqrt(min_vsize),(F32) sqrt(max_vsize)));
+ 		//setDebugText(llformat("%.0f:%.0f", (F32) sqrt(min_vsize),(F32) sqrt(max_vsize)));
+        setDebugText(debug_text.str());
  	}
 	else if (gPipeline.hasRenderDebugMask(LLPipeline::RENDER_DEBUG_FACE_AREA))
 	{
diff --git a/indra/newview/llxmlrpctransaction.cpp b/indra/newview/llxmlrpctransaction.cpp
index 32c8ce66a0..2b400c5586 100644
--- a/indra/newview/llxmlrpctransaction.cpp
+++ b/indra/newview/llxmlrpctransaction.cpp
@@ -395,7 +395,7 @@ void LLXMLRPCTransaction::Impl::init(XMLRPC_REQUEST request, bool useGzip, const
 
 	mHandler = LLXMLRPCTransaction::Handler::ptr_t(new Handler( mHttpRequest, this ));
 
-	mPostH = mHttpRequest->requestPost(LLCore::HttpRequest::DEFAULT_POLICY_ID, 0, 
+	mPostH = mHttpRequest->requestPost(LLCore::HttpRequest::DEFAULT_POLICY_ID,
 		mURI, body.get(), httpOpts, httpHeaders, mHandler);
 
 }
diff --git a/indra/newview/pipeline.cpp b/indra/newview/pipeline.cpp
index 9161b43159..91d276c8df 100644
--- a/indra/newview/pipeline.cpp
+++ b/indra/newview/pipeline.cpp
@@ -442,6 +442,7 @@ void LLPipeline::connectRefreshCachedSettingsSafe(const std::string name)
 
 void LLPipeline::init()
 {
+    LL_WARNS() << "Begin pipeline initialization" << LL_ENDL; // TODO: Remove after testing
 	refreshCachedSettings();
 
     mRT = &mMainRT;
@@ -460,6 +461,7 @@ void LLPipeline::init()
 	mInitialized = true;
 	
 	stop_glerror();
+    LL_WARNS() << "No GL errors yet. Pipeline initialization will continue." << LL_ENDL; // TODO: Remove after testing
 
 	//create render pass pools
 	getPool(LLDrawPool::POOL_ALPHA);
@@ -521,7 +523,9 @@ void LLPipeline::init()
 	
 	// Enable features
 		
+    LL_WARNS() << "Shader initialization start" << LL_ENDL; // TODO: Remove after testing
 	LLViewerShaderMgr::instance()->setShaders();
+    LL_WARNS() << "Shader initialization end" << LL_ENDL; // TODO: Remove after testing
 
 	stop_glerror();
 
@@ -3745,7 +3749,7 @@ void LLPipeline::touchTexture(LLViewerTexture* tex, F32 vsize)
     if (tex)
     {
         LLImageGL* gl_tex = tex->getGLTexture();
-        if (gl_tex && gl_tex->updateBindStats(gl_tex->mTextureMemory))
+        if (gl_tex && gl_tex->updateBindStats())
         {
             tex->setActive();
             tex->addTextureStats(vsize);
@@ -3815,25 +3819,47 @@ void LLPipeline::postSort(LLCamera& camera)
 			group->rebuildGeom();
 		}
 
-		for (LLSpatialGroup::draw_map_t::iterator j = group->mDrawMap.begin(); j != group->mDrawMap.end(); ++j)
-		{
-			LLSpatialGroup::drawmap_elem_t& src_vec = j->second;	
-			if (!hasRenderType(j->first))
-			{
-				continue;
-			}
-			
-			for (LLSpatialGroup::drawmap_elem_t::iterator k = src_vec.begin(); k != src_vec.end(); ++k)
-			{
+        for (LLSpatialGroup::draw_map_t::iterator j = group->mDrawMap.begin(); j != group->mDrawMap.end(); ++j)
+        {
+            LLSpatialGroup::drawmap_elem_t& src_vec = j->second;
+            if (!hasRenderType(j->first))
+            {
+                continue;
+            }
+
+            // DEBUG -- force a texture virtual size update every frame
+            /*if (group->getSpatialPartition()->mDrawableType == LLPipeline::RENDER_TYPE_VOLUME)
+            {
+                LL_PROFILE_ZONE_NAMED_CATEGORY_TEXTURE("plps - update vsize");
+                auto& entries = group->getData();
+                for (auto& entry : entries)
+                {
+                    if (entry)
+                    {
+                        auto* data = entry->getDrawable();
+                        if (data)
+                        {
+                            LLVOVolume* volume = ((LLDrawable*)data)->getVOVolume();
+                            if (volume)
+                            {
+                                volume->updateTextureVirtualSize(true);
+                            }
+                        }
+                    }
+                }
+            }*/
+
+            for (LLSpatialGroup::drawmap_elem_t::iterator k = src_vec.begin(); k != src_vec.end(); ++k)
+            {
                 LLDrawInfo* info = *k;
-				
-				sCull->pushDrawInfo(j->first, info);
+
+                sCull->pushDrawInfo(j->first, info);
                 if (!sShadowRender && !sReflectionRender && !gCubeSnapshot)
                 {
                     touchTextures(info);
                     addTrianglesDrawn(info->mCount, info->mDrawMode);
                 }
-			}
+            }
 		}
 
 		if (hasRenderType(LLPipeline::RENDER_TYPE_PASS_ALPHA))
diff --git a/indra/newview/skins/default/xui/en/floater_preferences_graphics_advanced.xml b/indra/newview/skins/default/xui/en/floater_preferences_graphics_advanced.xml
index b7708b057d..97a87d56f4 100644
--- a/indra/newview/skins/default/xui/en/floater_preferences_graphics_advanced.xml
+++ b/indra/newview/skins/default/xui/en/floater_preferences_graphics_advanced.xml
@@ -272,22 +272,6 @@
      Hardware
   </text>
 
-  <slider
-    control_name="TextureMemory"
-    decimal_digits="0"
-    follows="left|top"
-    height="16"
-    increment="16"
-    initial_value="32"
-    label="Texture Memory (MB):"
-    label_width="185"
-    layout="topleft"
-    left="30"
-    max_val="4096"
-    name="GraphicsCardTextureMemory"
-    tool_tip="Amount of memory to allocate for textures. Defaults to video card memory. Reducing this may improve performance but may also make textures blurry."
-    top_delta="16"
-    width="335" />
 
   <check_box
     control_name="RenderAnisotropic"
diff --git a/indra/newview/skins/default/xui/en/floater_texture_fetch_debugger.xml b/indra/newview/skins/default/xui/en/floater_texture_fetch_debugger.xml
deleted file mode 100644
index 9278a1a598..0000000000
--- a/indra/newview/skins/default/xui/en/floater_texture_fetch_debugger.xml
+++ /dev/null
@@ -1,440 +0,0 @@
-<?xml version="1.0" encoding="utf-8" standalone="yes" ?>
-<floater
- legacy_header_height="18"
- can_minimize="false"
- height="600"
- layout="topleft"
- name="TexFetchDebugger"
- help_topic="texfetchdebugger"
- title="Texture Fetching Debugger"
- width="540">
-  <text
-   type="string"
-   length="1"
-   follows="left|top"
-   height="25"
-   layout="topleft"
-   left="10"
-   name="total_num_fetched_label"
-   top="30"
-   width="400">
-    1, Total number of fetched textures: [NUM]
-  </text>
-  <text
-   type="string"
-   length="1"
-   follows="left|top"
-   height="25"
-   layout="topleft"
-   left_delta="0"
-   name="total_num_fetching_requests_label"
-   top_delta="25"
-   width="400">
-    2, Total number of fetching requests: [NUM]
-  </text>
-  <text
-   type="string"
-   length="1"
-   follows="left|top"
-   height="25"
-   layout="topleft"
-   left_delta="0"
-   name="total_num_cache_hits_label"
-   top_delta="25"
-   width="400">
-    3, Total number of cache hits: [NUM]
-  </text>
-  <text
-   type="string"
-   length="1"
-   follows="left|top"
-   height="25"
-   layout="topleft"
-   left_delta="0"
-   name="total_num_visible_tex_label"
-   top_delta="25"
-   width="400">
-    4, Total number of visible textures: [NUM]
-  </text>
-  <text
-   type="string"
-   length="1"
-   follows="left|top"
-   height="25"
-   layout="topleft"
-   left_delta="0"
-   name="total_num_visible_tex_fetch_req_label"
-   top_delta="25"
-   width="450">
-    5, Total number of visible texture fetching requests: [NUM]
-  </text>
-  <text
-   type="string"
-   length="1"
-   follows="left|top"
-   height="25"
-   layout="topleft"
-   left_delta="0"
-   name="total_fetched_data_label"
-   top_delta="25"
-   width="530">
-    6, Total number of fetched data: [SIZE1]KB, Decoded Data: [SIZE2]KB, [PIXEL]MPixels
-  </text>
-  <text
-   type="string"
-   length="1"
-   follows="left|top"
-   height="25"
-   layout="topleft"
-   left_delta="0"
-   name="total_fetched_vis_data_label"
-   top_delta="25"
-   width="480">
-    7, Total number of visible data: [SIZE1]KB, Decoded Data: [SIZE2]KB
-  </text>
-  <text
-   type="string"
-   length="1"
-   follows="left|top"
-   height="25"
-   layout="topleft"
-   left_delta="0"
-   name="total_fetched_rendered_data_label"
-   top_delta="25"
-   width="530">
-    8, Total number of rendered data: [SIZE1]KB, Decoded Data: [SIZE2]KB, [PIXEL]MPixels
-  </text>
-  <text
-   type="string"
-   length="1"
-   follows="left|top"
-   height="25"
-   layout="topleft"
-   left_delta="0"
-   name="total_time_cache_read_label"
-   top_delta="25"
-   width="400">
-    9, Total time on cache readings: [TIME] seconds
-  </text>
-  <text
-   type="string"
-   length="1"
-   follows="left|top"
-   height="25"
-   layout="topleft"
-   left_delta="0"
-   name="total_time_cache_write_label"
-   top_delta="25"
-   width="400">
-    10, Total time on cache writings: [TIME] seconds
-  </text>
-  <text
-   type="string"
-   length="1"
-   follows="left|top"
-   height="25"
-   layout="topleft"
-   left_delta="0"
-   name="total_time_decode_label"
-   top_delta="25"
-   width="400">
-    11, Total time on decodings: [TIME] seconds
-  </text>
-  <text
-   type="string"
-   length="1"
-   follows="left|top"
-   height="25"
-   layout="topleft"
-   left_delta="0"
-   name="total_time_gl_label"
-   top_delta="25"
-   width="400">
-    12, Total time on gl texture creation: [TIME] seconds
-  </text>
-  <text
-   type="string"
-   length="1"
-   follows="left|top"
-   height="25"
-   layout="topleft"
-   left_delta="0"
-   name="total_time_http_label"
-   top_delta="25"
-   width="400">
-    13, Total time on HTTP fetching: [TIME] seconds
-  </text>
-  <text
-   type="string"
-   length="1"
-   follows="left|top"
-   height="25"
-   layout="topleft"
-   left_delta="0"
-   name="total_time_fetch_label"
-   top_delta="25"
-   width="400">
-    14, Total time on entire fetching: [TIME] seconds
-  </text>
-  <text
-  type="string"
-  length="1"
-  follows="left|top"
-  height="25"
-  layout="topleft"
-  left_delta="0"
-  name="total_time_refetch_vis_cache_label"
-  top_delta="25"
-  width="540">
-    15, Refetching visibles from cache, Time: [TIME] seconds, Fetched: [SIZE]KB, [PIXEL]MPixels
-  </text>
-  <text
-  type="string"
-  length="1"
-  follows="left|top"
-  height="25"
-  layout="topleft"
-  left_delta="0"
-  name="total_time_refetch_all_cache_label"
-  top_delta="25"
-  width="540">
-    16, Refetching all textures from cache, Time: [TIME] seconds, Fetched: [SIZE]KB, [PIXEL]MPixels
-  </text>
-  <text
-  type="string"
-  length="1"
-  follows="left|top"
-  height="25"
-  layout="topleft"
-  left_delta="0"
-  name="total_time_refetch_vis_http_label"
-  top_delta="25"
-  width="540">
-    17, Refetching visibles from HTTP, Time: [TIME] seconds, Fetched: [SIZE]KB, [PIXEL]MPixels
-  </text>
-  <text
-  type="string"
-  length="1"
-  follows="left|top"
-  height="25"
-  layout="topleft"
-  left_delta="0"
-  name="total_time_refetch_all_http_label"
-  top_delta="25"
-  width="540">
-    18, Refetching all textures from HTTP, Time: [TIME] seconds, Fetched: [SIZE]KB, [PIXEL]MPixels
-  </text>
-  <spinner
-     decimal_digits="2"
-     follows="left|top"
-     height="20"
-     increment="0.01"
-     initial_value="1.0"
-     label="19, Ratio of Texel/Pixel:"
-     label_width="130"
-     layout="topleft"
-     left_delta="0"
-     max_val="10.0"
-     min_val="0.01"
-     name="texel_pixel_ratio"
-     top_delta="30"
-     width="200">
-    <spinner.commit_callback
-		function="TexFetchDebugger.ChangeTexelPixelRatio" />
-  </spinner>
-  <text
-  type="string"
-  length="1"
-  follows="left|top"
-  height="25"
-  layout="topleft"
-  left_delta="0"
-  name="texture_source_label"
-  top_delta="30"
-  width="110">
-    20, Texture Source:
-  </text>
-  <radio_group
-     control_name="TextureFetchSource"
-     follows="top|left"
-     draw_border="false"
-     height="25"
-     layout="topleft"
-     left_pad="0"
-     name="texture_source"
-     top_delta="0"
-     width="264">
-    <radio_item
-     height="16"
-     label="Cache + HTTP"
-     layout="topleft"
-     left="3"
-     name="0"
-     top="0"
-     width="100" />
-    <radio_item
-     height="16"
-     label="HTTP Only"
-     layout="topleft"
-     left_delta="100"
-     name="1"
-     top_delta="0"
-     width="200" />
-  </radio_group>
-  <button
-   follows="left|top"
-   height="20"
-   label="Start"
-   layout="topleft"
-   left="10"
-   name="start_btn"
-   top_delta="20"
-   width="70">
-    <button.commit_callback
-		function="TexFetchDebugger.Start" />
-  </button>
-  <button
-   follows="left|top"
-   height="20"
-   label="Reset"
-   layout="topleft"
-   left_pad="7"
-   name="clear_btn"
-   top_delta="0"
-   width="70">
-    <button.commit_callback
-		function="TexFetchDebugger.Clear" />
-  </button>
-  <button
-   follows="left|top"
-   height="20"
-   label="Close"
-   layout="topleft"
-   left_pad="7"
-   name="close_btn"
-   top_delta="0"
-   width="70">
-    <button.commit_callback
-		function="TexFetchDebugger.Close" />
-  </button>
-  <button
-   follows="left|top"
-   height="22"
-   label="Reset Fetching Time"
-   layout="topleft"
-   left_pad="175"
-   name="reset_time_btn"
-   top_delta="0"
-   width="120">
-    <button.commit_callback
-		function="TexFetchDebugger.ResetFetchTime" />
-  </button>
-  <button
-   follows="left|top"
-   height="20"
-   label="Cache Read"
-   layout="topleft"
-   left="10"
-   name="cacheread_btn"
-   top_delta="20"
-   width="80">
-    <button.commit_callback
-		function="TexFetchDebugger.CacheRead" />
-  </button>
-  <button
-   follows="left|top"
-   height="20"
-   label="Cache Write"
-   layout="topleft"
-   left_pad="7"
-   name="cachewrite_btn"
-   top_delta="0"
-   width="80">
-    <button.commit_callback
-		function="TexFetchDebugger.CacheWrite" />
-  </button>
-  <button
-   follows="left|top"
-   height="20"
-   label="HTTP"
-   layout="topleft"
-   left_pad="7"
-   name="http_btn"
-   top_delta="0"
-   width="70">
-    <button.commit_callback
-		function="TexFetchDebugger.HTTPLoad" />
-  </button>
-  <button
-   follows="left|top"
-   height="20"
-   label="Decode"
-   layout="topleft"
-   left_pad="7"
-   name="decode_btn"
-   top_delta="0"
-   width="70">
-    <button.commit_callback
-		function="TexFetchDebugger.Decode" />
-  </button>
-  <button
-   follows="left|top"
-   height="20"
-   label="GL Texture"
-   layout="topleft"
-   left_pad="7"
-   name="gl_btn"
-   top_delta="0"
-   width="70">
-    <button.commit_callback
-		function="TexFetchDebugger.GLTexture" />
-  </button>
-  <button
-   follows="left|top"
-   height="20"
-   label="Refetch Vis Cache"
-   layout="topleft"
-   left="10"
-   name="refetchviscache_btn"
-   top_delta="20"
-   width="120">
-    <button.commit_callback
-		function="TexFetchDebugger.RefetchVisCache" />
-  </button>
-  <button
-   follows="left|top"
-   height="20"
-   label="Refetch All Cache"
-   layout="topleft"
-   left_pad="7"
-   name="refetchallcache_btn"
-   top_delta="0"
-   width="120">
-    <button.commit_callback
-		function="TexFetchDebugger.RefetchAllCache" />
-  </button>
-  <button
-   follows="left|top"
-   height="20"
-   label="Refetch Vis HTTP"
-   layout="topleft"
-   left_pad="7"
-   name="refetchvishttp_btn"
-   top_delta="0"
-   width="120">
-    <button.commit_callback
-		function="TexFetchDebugger.RefetchVisHTTP" />
-  </button>
-  <button
-   follows="left|top"
-   height="20"
-   label="Refetch All HTTP"
-   layout="topleft"
-   left_pad="7"
-   name="refetchallhttp_btn"
-   top_delta="0"
-   width="120">
-    <button.commit_callback
-		function="TexFetchDebugger.RefetchAllHTTP" />
-  </button>
-</floater>
diff --git a/indra/newview/skins/default/xui/en/menu_viewer.xml b/indra/newview/skins/default/xui/en/menu_viewer.xml
index beb5a5048d..cf99240908 100644
--- a/indra/newview/skins/default/xui/en/menu_viewer.xml
+++ b/indra/newview/skins/default/xui/en/menu_viewer.xml
@@ -2465,20 +2465,6 @@ function="World.EnvPreset"
                function="Advanced.ToggleConsole"
                parameter="scene monitor" />
             </menu_item_check>
-            <menu_item_call
-              enabled="false"
-              visible="false"
-              label="Texture Fetch Debug Console"
-              name="Texture Fetch Debug Console">
-              <menu_item_call.on_click
-                function="Floater.Show"
-                parameter="tex_fetch_debugger" />
-              <on_enable
-                function="Develop.SetTexFetchDebugger" />
-              <on_visible
-                function="Develop.SetTexFetchDebugger" />
-            </menu_item_call>
-          
             <menu_item_separator/>
 
             <menu_item_call
diff --git a/indra/newview/tests/llviewercontrollistener_test.cpp b/indra/newview/tests/llviewercontrollistener_test.cpp
new file mode 100644
index 0000000000..6d100ef984
--- /dev/null
+++ b/indra/newview/tests/llviewercontrollistener_test.cpp
@@ -0,0 +1,174 @@
+/**
+ * @file   llviewercontrollistener_test.cpp
+ * @author Nat Goodspeed
+ * @date   2022-06-09
+ * @brief  Test for llviewercontrollistener.
+ * 
+ * $LicenseInfo:firstyear=2022&license=viewerlgpl$
+ * Copyright (c) 2022, Linden Research, Inc.
+ * $/LicenseInfo$
+ */
+
+// Precompiled header
+#include "llviewerprecompiledheaders.h"
+// associated header
+#include "llviewercontrollistener.h"
+// STL headers
+// std headers
+// external library headers
+// other Linden headers
+#include "../test/lltut.h"
+#include "../test/catch_and_store_what_in.h" // catch_what()
+#include "commoncontrol.h"
+#include "llcontrol.h"              // LLControlGroup
+#include "llviewercontrollistener.h"
+
+/*****************************************************************************
+*   TUT
+*****************************************************************************/
+namespace tut
+{
+    void ensure_contains(const std::string& msg, const std::string& substr)
+    {
+        ensure_contains("Exception does not contain " + substr, msg, substr);
+    }
+
+    struct llviewercontrollistener_data
+    {
+        LLControlGroup Global{"FakeGlobal"};
+
+        llviewercontrollistener_data()
+        {
+            Global.declareString("strvar", "woof", "string variable");
+            // together we will stroll the boolvar, ma cherie
+            Global.declareBOOL("boolvar",  TRUE, "bool variable");
+        }
+    };
+    typedef test_group<llviewercontrollistener_data> llviewercontrollistener_group;
+    typedef llviewercontrollistener_group::object object;
+    llviewercontrollistener_group llviewercontrollistenergrp("llviewercontrollistener");
+
+    template<> template<>
+    void object::test<1>()
+    {
+        set_test_name("CommonControl no listener");
+        // Not implemented: the linker drags in LLViewerControlListener when
+        // we bring in LLViewerControl.
+    }
+
+    template<> template<>
+    void object::test<2>()
+    {
+        set_test_name("CommonControl bad group");
+        std::string threw{ catch_what<LL::CommonControl::ParamError>(
+                [](){ LL::CommonControl::get("Nonexistent", "Variable"); }) };
+        ensure_contains(threw, "group");
+        ensure_contains(threw, "Nonexistent");
+    }
+
+    template<> template<>
+    void object::test<3>()
+    {
+        set_test_name("CommonControl bad variable");
+        std::string threw{ catch_what<LL::CommonControl::ParamError>(
+                [](){ LL::CommonControl::get("FakeGlobal", "Nonexistent"); }) };
+        ensure_contains(threw, "key");
+        ensure_contains(threw, "Nonexistent");
+    }
+
+    template<> template<>
+    void object::test<4>()
+    {
+        set_test_name("CommonControl toggle string");
+        std::string threw{ catch_what<LL::CommonControl::ParamError>(
+                [](){ LL::CommonControl::toggle("FakeGlobal", "strvar"); }) };
+        ensure_contains(threw, "non-boolean");
+        ensure_contains(threw, "strvar");
+    }
+
+    template<> template<>
+    void object::test<5>()
+    {
+        set_test_name("CommonControl list bad group");
+        std::string threw{ catch_what<LL::CommonControl::ParamError>(
+                [](){ LL::CommonControl::get_vars("Nonexistent"); }) };
+        ensure_contains(threw, "group");
+        ensure_contains(threw, "Nonexistent");
+    }
+
+    template<> template<>
+    void object::test<6>()
+    {
+        set_test_name("CommonControl get");
+        auto strvar{ LL::CommonControl::get("FakeGlobal", "strvar") };
+        ensure_equals(strvar, "woof");
+        auto boolvar{ LL::CommonControl::get("FakeGlobal", "boolvar") };
+        ensure(boolvar);
+    }
+
+    template<> template<>
+    void object::test<7>()
+    {
+        set_test_name("CommonControl set, set_default, toggle");
+
+        std::string newstr{ LL::CommonControl::set("FakeGlobal", "strvar", "mouse").asString() };
+        ensure_equals(newstr, "mouse");
+        ensure_equals(LL::CommonControl::get("FakeGlobal", "strvar").asString(), "mouse");
+        ensure_equals(LL::CommonControl::set_default("FakeGlobal", "strvar").asString(), "woof");
+
+        bool newbool{ LL::CommonControl::set("FakeGlobal", "boolvar", false) };
+        ensure(! newbool);
+        ensure(! LL::CommonControl::get("FakeGlobal", "boolvar").asBoolean());
+        ensure(LL::CommonControl::set_default("FakeGlobal", "boolvar").asBoolean());
+        ensure(! LL::CommonControl::toggle("FakeGlobal", "boolvar").asBoolean());
+    }
+
+    template<> template<>
+    void object::test<8>()
+    {
+        set_test_name("CommonControl get_def");
+        LLSD def{ LL::CommonControl::get_def("FakeGlobal", "strvar") };
+        ensure_equals(
+            def,
+            llsd::map("name", "strvar",
+                      "type", "String",
+                      "value", "woof",
+                      "comment", "string variable"));
+    }
+
+    template<> template<>
+    void object::test<9>()
+    {
+        set_test_name("CommonControl get_groups");
+        std::vector<std::string> groups{ LL::CommonControl::get_groups() };
+        ensure_equals(groups.size(), 1);
+        ensure_equals(groups[0], "FakeGlobal");
+    }
+
+    template<> template<>
+    void object::test<10>()
+    {
+        set_test_name("CommonControl get_vars");
+        LLSD vars{ LL::CommonControl::get_vars("FakeGlobal") };
+        // convert from array (unpredictable order) to map
+        LLSD varsmap{ LLSD::emptyMap() };
+        for (auto& var : llsd::inArray(vars))
+        {
+            varsmap[var["name"].asString()] = var;
+        }
+        // comparing maps is order-insensitive
+        ensure_equals(
+            varsmap,
+            llsd::map(
+                "strvar",
+                llsd::map("name", "strvar",
+                          "type", "String",
+                          "value", "woof",
+                          "comment", "string variable"),
+                "boolvar",
+                llsd::map("name", "boolvar",
+                          "type", "Boolean",
+                          "value", TRUE,
+                          "comment", "bool variable")));
+    }
+} // namespace tut
diff --git a/indra/test/test.cpp b/indra/test/test.cpp
index bb48216b2b..28f25087ac 100644
--- a/indra/test/test.cpp
+++ b/indra/test/test.cpp
@@ -401,7 +401,7 @@ public:
 	{
 		// Per http://confluence.jetbrains.net/display/TCD65/Build+Script+Interaction+with+TeamCity#BuildScriptInteractionwithTeamCity-ServiceMessages
 		std::string result;
-		BOOST_FOREACH(char c, str)
+		for (char c : str)
 		{
 			switch (c)
 			{