Merge branch '26.3'

6 files changed, 187 insertions, 45 deletions

diff --git a/indra/llcommon/llmemory.cpp b/indra/llcommon/llmemory.cpp
index ba48319a16..4e44b9a56a 100644
--- a/indra/llcommon/llmemory.cpp
+++ b/indra/llcommon/llmemory.cpp
@@ -4,7 +4,7 @@
  *
  * $LicenseInfo:firstyear=2002&license=viewerlgpl$
  * Second Life Viewer Source Code
- * Copyright (C) 2010, Linden Research, Inc.
+ * Copyright (C) 2026, 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
@@ -52,6 +52,9 @@
 
 //static
 
+// On windows commit charge information is vital for OOM diagnosis.
+U32Megabytes LLMemory::sAvailCommitMemInMB(U32_MAX);
+
 // most important memory metric for texture streaming
 //  On Windows, this should agree with resource monitor -> performance -> memory -> available
 //  On OS X, this should be activity monitor -> memory -> (physical memory - memory used)
@@ -70,6 +73,12 @@ U32Kilobytes LLMemory::sAllocatedMemInKB(0);
 
 U32Kilobytes LLMemory::sAllocatedPageSizeInKB(0);
 
+LLFrameTimer LLMemory::sMemoryCheckTimer;
+F32 LLMemory::sSysMemoryFactor = 1.f;
+U32 LLMemory::sFactorLastFrameCount = 0;
+
+static const S32Megabytes MEM_LOW_THRESHOLD = S32Megabytes(256);
+
 
 static LLTrace::SampleStatHandle<F64Megabytes> sAllocatedMem("allocated_mem", "active memory in use by application");
 static LLTrace::SampleStatHandle<F64Megabytes> sVirtualMem("virtual_mem", "virtual memory assigned to application");
@@ -102,23 +111,14 @@ void LLMemory::updateMemoryInfo()
 {
     LL_PROFILE_ZONE_SCOPED;
 
+    sMemoryCheckTimer.reset();
     sMaxPhysicalMemInKB = gSysMemory.getPhysicalMemoryKB();
 
-    U32Kilobytes avail_mem;
-    LLMemoryInfo::getAvailableMemoryKB(avail_mem);
-    sAvailPhysicalMemInKB = avail_mem;
+    LLMemoryInfo::updateAvailableMemory();
 
 #if LL_WINDOWS
-    PROCESS_MEMORY_COUNTERS counters;
-
-    if (!GetProcessMemoryInfo(GetCurrentProcess(), &counters, sizeof(counters)))
-    {
-        LL_WARNS() << "GetProcessMemoryInfo failed" << LL_ENDL;
-        return ;
-    }
-
-    sAllocatedMemInKB = U32Kilobytes::convert(U64Bytes(counters.WorkingSetSize));
-    sAllocatedPageSizeInKB = U32Kilobytes::convert(U64Bytes(counters.PagefileUsage));
+    // On windows updateAvailableMemory fills sAvailPhysicalMemInKB,
+    //sAllocatedMemInKB and sAllocatedPageSizeInKB
     sample(sVirtualMem, sAllocatedPageSizeInKB);
 
 #elif defined(LL_DARWIN)
@@ -201,6 +201,97 @@ void LLMemory::logMemoryInfo(bool update)
     LL_INFOS() << llformat("Current max usable memory: %.2f MB", sMaxPhysicalMemInKB / 1024.0) << LL_ENDL;
 }
 
+void LLMemory::updateFreeSystemMemory()
+{
+    if (sMemoryCheckTimer.getElapsedTimeF32() >= 1.f) //once per second.
+    {
+        LLMemory::updateMemoryInfo(); // resets the timer
+    }
+}
+
+F32 LLMemory::getSystemMemoryBudgetFactor()
+{
+    // Only update once per frame
+    U32 current_frame = LLFrameTimer::getFrameCount();
+    if (sFactorLastFrameCount == current_frame)
+    {
+        return sSysMemoryFactor;
+    }
+    sFactorLastFrameCount = current_frame;
+
+    updateFreeSystemMemory();
+#if LL_WINDOWS
+    S32Megabytes free_sys_mem = getAvailableCommitMemMB();
+#else
+    S32Megabytes free_sys_mem = getAvailableMemKB();
+#endif
+    bool is_sys_low = free_sys_mem < MEM_LOW_THRESHOLD;
+    static bool was_low = false;
+
+    // sSysMemoryFactor affects draw distance
+    //
+    // We only decrement when more than 406MB is free, but increment
+    // when below 256MB free. This should provide a stable value
+    // in the 256-406MB range to avoid draw range fluctuations.
+    //
+    // Draw range reduction is a last resort, texture bias is supposed
+    // to free at least some memory before we get here.
+    // Note: textures were mostly moved to vram, we might want to
+    // detach texture bias from system memory.
+    if (is_sys_low)
+    {
+        // debt is a negative value since MIN_FREE_MAIN_MEMORY > free memory.
+        S32Megabytes sys_budget_debt = free_sys_mem - MEM_LOW_THRESHOLD;
+
+        // Leave some padding, otherwise we will crash out of memory before hitting factor 2.
+        const S32Megabytes PAD_BUFFER(32);
+        S32Megabytes budget_target = MEM_LOW_THRESHOLD - PAD_BUFFER;
+        if (!was_low)
+        {
+            // Result should range from 1 at 0 debt to 2 at -224 debt, 2.14 at -256MB
+            F32 new_factor = 1.f - (F32)sys_budget_debt.value() / (F32)budget_target.value();
+            sSysMemoryFactor = llmax(sSysMemoryFactor, new_factor);
+        }
+        else
+        {
+            // Slowly ramp up factor to free memory (increasing factor decreases draw range)
+            constexpr F32 MAX_INCREMENT = 0.05f;
+            F32 increment = MAX_INCREMENT * llmax(-(F32)sys_budget_debt.value() / (F32)budget_target.value(), 0.f);
+            sSysMemoryFactor += increment * LLFrameTimer::getFrameDeltaTimeF32();
+        }
+        sSysMemoryFactor = llclamp(sSysMemoryFactor, 1.f, 2.f);
+    }
+    else
+    {
+        // Only start ramping down when we have breathing room.
+        // This should be under the value of isSystemMemoryLow to not throw texture
+        // bias into 1.5+ territory each time we fluctuate around isSystemMemoryLow's
+        // threshold.
+        const S32Megabytes MEM_THRESHOLD = MEM_LOW_THRESHOLD + S32Megabytes(150);
+        if (free_sys_mem > MEM_THRESHOLD && sSysMemoryFactor > 1.f)
+        {
+            // Ramp down factor over time.
+            constexpr F32 DECREMENT = 0.02f;
+            sSysMemoryFactor -= DECREMENT * LLFrameTimer::getFrameDeltaTimeF32();
+            sSysMemoryFactor = llclamp(sSysMemoryFactor, 1.f, 2.f);
+        }
+    }
+    was_low = is_sys_low;
+
+    return sSysMemoryFactor;
+}
+
+#if LL_WINDOWS
+//static
+U32Megabytes LLMemory::getAvailableCommitMemMB()
+{
+    // Commit charge combines page file and ram,
+    // theoretical limit is 128TB on 64bit windows.
+    // Store as MB instead of KB to prevent overflow.
+    return sAvailCommitMemInMB;
+}
+#endif
+
 //static
 U32Kilobytes LLMemory::getAvailableMemKB()
 {
diff --git a/indra/llcommon/llmemory.h b/indra/llcommon/llmemory.h
index c06ae93766..5ac114cac9 100644
--- a/indra/llcommon/llmemory.h
+++ b/indra/llcommon/llmemory.h
@@ -4,7 +4,7 @@
  *
  * $LicenseInfo:firstyear=2002&license=viewerlgpl$
  * Second Life Viewer Source Code
- * Copyright (C) 2010, Linden Research, Inc.
+ * Copyright (C) 2026, 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
@@ -27,6 +27,7 @@
 #define LLMEMORY_H
 
 #include "linden_common.h"
+#include "llframetimer.h"
 #include "llunits.h"
 #include "stdtypes.h"
 #if !LL_WINDOWS
@@ -428,17 +429,31 @@ public:
     static void initMaxHeapSizeGB(F32Gigabytes max_heap_size);
     static void updateMemoryInfo() ;
     static void logMemoryInfo(bool update = false);
+    static F32 getSystemMemoryBudgetFactor();
 
+#if LL_WINDOWS
+    // Commit charge is a Windows-only concept, combines page file and ram
+    static U32Megabytes getAvailableCommitMemMB();
+#endif
     static U32Kilobytes getAvailableMemKB() ;
     static U32Kilobytes getMaxMemKB() ;
     static U32Kilobytes getAllocatedMemKB() ;
 private:
+    static void updateFreeSystemMemory();
+    // LLMemoryInfo directly updates memory stats
+    friend class LLMemoryInfo;
+
+    static U32Megabytes sAvailCommitMemInMB;
     static U32Kilobytes sAvailPhysicalMemInKB ;
     static U32Kilobytes sMaxPhysicalMemInKB ;
     static U32Kilobytes sAllocatedMemInKB;
     static U32Kilobytes sAllocatedPageSizeInKB ;
 
     static U32Kilobytes sMaxHeapSizeInKB;
+
+    static LLFrameTimer sMemoryCheckTimer;
+    static F32 sSysMemoryFactor;
+    static U32 sFactorLastFrameCount;
 };
 
 // LLRefCount moved to llrefcount.h
diff --git a/indra/llcommon/llsys.cpp b/indra/llcommon/llsys.cpp
index 542de4ee67..452acf4322 100644
--- a/indra/llcommon/llsys.cpp
+++ b/indra/llcommon/llsys.cpp
@@ -4,7 +4,7 @@
  *
  * $LicenseInfo:firstyear=2002&license=viewerlgpl$
  * Second Life Viewer Source Code
- * Copyright (C) 2010, Linden Research, Inc.
+ * Copyright (C) 2026, 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
@@ -43,6 +43,7 @@
 #include "llerrorcontrol.h"
 #include "llevents.h"
 #include "llformat.h"
+#include "llmemory.h"
 #include "llregex.h"
 #include "lltimer.h"
 #include "llsdserialize.h"
@@ -811,15 +812,13 @@ U32Kilobytes LLMemoryInfo::getPhysicalMemoryKB() const
 }
 
 //static
-void LLMemoryInfo::getAvailableMemoryKB(U32Kilobytes& avail_mem_kb)
+void LLMemoryInfo::updateAvailableMemory()
 {
     LL_PROFILE_ZONE_SCOPED_CATEGORY_MEMORY;
 #if LL_WINDOWS
-    // Sigh, this shouldn't be a static method, then we wouldn't have to
-    // reload this data separately from refresh()
-    LLSD statsMap(loadStatsMap());
-
-    avail_mem_kb = (U32Kilobytes)statsMap["Avail Physical KB"].asInteger();
+    // On windows loadStatsMap will fill sAvailPhysicalMemInKB,
+    // sAvailCommitMemInMB, sAllocatedMemInKB and sAllocatedPageSizeInKB
+    loadStatsMap();
 
 #elif LL_DARWIN
     // use host_statistics64 to get memory info
@@ -831,11 +830,11 @@ void LLMemoryInfo::getAvailableMemoryKB(U32Kilobytes& avail_mem_kb)
     kern_return_t result = host_statistics64(host, HOST_VM_INFO64, reinterpret_cast<host_info_t>(&vmstat), &count);
     if (result == KERN_SUCCESS)
     {
-        avail_mem_kb = U64Bytes((vmstat.free_count + vmstat.inactive_count) * page_size);
+        LLMemory::sAvailPhysicalMemInKB = U64Bytes((vmstat.free_count + vmstat.inactive_count) * page_size);
     }
     else
     {
-        avail_mem_kb = (U32Kilobytes)-1;
+        LLMemory::sAvailPhysicalMemInKB = (U32Kilobytes)-1;
     }
 
 #elif LL_LINUX
@@ -889,12 +888,12 @@ void LLMemoryInfo::getAvailableMemoryKB(U32Kilobytes& avail_mem_kb)
     // (could also run 'free', but easier to read a file than run a program)
     LLSD statsMap(loadStatsMap());
 
-    avail_mem_kb = (U32Kilobytes)statsMap["MemFree"].asInteger();
+    LLMemory::sAvailPhysicalMemInKB = (U32Kilobytes)statsMap["MemFree"].asInteger();
 #else
     //do not know how to collect available memory info for other systems.
     //leave it blank here for now.
 
-    avail_mem_kb = (U32Kilobytes)-1 ;
+    LLMemory::sAvailPhysicalMemInKB = (U32Kilobytes)-1 ;
 #endif
 }
 
@@ -965,15 +964,24 @@ LLSD LLMemoryInfo::loadStatsMap()
     state.dwLength = sizeof(state);
     GlobalMemoryStatusEx(&state);
 
-    DWORDLONG div = 1024;
+    static constexpr DWORDLONG div = 1024;
 
-    stats.add("Percent Memory use", state.dwMemoryLoad/div);
+    stats.add("Percent Memory use", state.dwMemoryLoad);
     stats.add("Total Physical KB",  state.ullTotalPhys/div);
     stats.add("Avail Physical KB",  state.ullAvailPhys/div);
+
+    // Despite the confusing naming "PageFile" , these values
+    // actually represent the committed memory limit for
+    // the system or the current process, whichever is smaller.
     stats.add("Total page KB",      state.ullTotalPageFile/div);
     stats.add("Avail page KB",      state.ullAvailPageFile/div);
-    stats.add("Total Virtual KB",   state.ullTotalVirtual/div);
-    stats.add("Avail Virtual KB",   state.ullAvailVirtual/div);
+
+    static constexpr DWORDLONG mb_div = 1024 * 1024;
+    stats.add("Total Virtual MB", state.ullTotalVirtual/mb_div);  // ~134 million MB
+    stats.add("Avail Virtual MB", state.ullAvailVirtual/mb_div);
+
+    LLMemory::sAvailPhysicalMemInKB = U32Kilobytes::convert(U64Bytes(state.ullAvailPhys));
+    LLMemory::sAvailCommitMemInMB = U32Megabytes::convert(U64Bytes(state.ullAvailPageFile));
 
     // SL-12122 - Call to GetPerformanceInfo() was removed here. Took
     // on order of 10 ms, causing unacceptable frame time spike every
@@ -989,18 +997,38 @@ LLSD LLMemoryInfo::loadStatsMap()
     // specifically accepts PROCESS_MEMORY_COUNTERS*, and since this is a
     // classic-C API, PROCESS_MEMORY_COUNTERS_EX isn't a subclass. Cast the
     // pointer.
-    GetProcessMemoryInfo(GetCurrentProcess(), (PROCESS_MEMORY_COUNTERS*) &pmem, sizeof(pmem));
+    if (GetProcessMemoryInfo(GetCurrentProcess(), (PROCESS_MEMORY_COUNTERS*)&pmem, sizeof(pmem)))
+    {
+        LLMemory::sAllocatedMemInKB = U32Kilobytes::convert(U64Bytes(pmem.WorkingSetSize));
+        LLMemory::sAllocatedPageSizeInKB = U32Kilobytes::convert(U64Bytes(pmem.PagefileUsage));
 
-    stats.add("Page Fault Count",              pmem.PageFaultCount);
-    stats.add("PeakWorkingSetSize KB",         pmem.PeakWorkingSetSize/div);
-    stats.add("WorkingSetSize KB",             pmem.WorkingSetSize/div);
-    stats.add("QutaPeakPagedPoolUsage KB",     pmem.QuotaPeakPagedPoolUsage/div);
-    stats.add("QuotaPagedPoolUsage KB",        pmem.QuotaPagedPoolUsage/div);
-    stats.add("QuotaPeakNonPagedPoolUsage KB", pmem.QuotaPeakNonPagedPoolUsage/div);
-    stats.add("QuotaNonPagedPoolUsage KB",     pmem.QuotaNonPagedPoolUsage/div);
-    stats.add("PagefileUsage KB",              pmem.PagefileUsage/div);
-    stats.add("PeakPagefileUsage KB",          pmem.PeakPagefileUsage/div);
-    stats.add("PrivateUsage KB",               pmem.PrivateUsage/div);
+        stats.add("Page Fault Count", pmem.PageFaultCount);
+        stats.add("PeakWorkingSetSize KB", pmem.PeakWorkingSetSize / div);
+        stats.add("WorkingSetSize KB", pmem.WorkingSetSize / div);
+        stats.add("QuotaPeakPagedPoolUsage KB", pmem.QuotaPeakPagedPoolUsage / div);
+        stats.add("QuotaPagedPoolUsage KB", pmem.QuotaPagedPoolUsage / div);
+        stats.add("QuotaPeakNonPagedPoolUsage KB", pmem.QuotaPeakNonPagedPoolUsage / div);
+        stats.add("QuotaNonPagedPoolUsage KB", pmem.QuotaNonPagedPoolUsage / div);
+        stats.add("PagefileUsage KB", pmem.PagefileUsage / div);
+        stats.add("PeakPagefileUsage KB", pmem.PeakPagefileUsage / div);
+        stats.add("PrivateUsage KB", pmem.PrivateUsage / div);
+    }
+    else
+    {
+        LLMemory::sAllocatedMemInKB = U32Kilobytes(0);
+        LLMemory::sAllocatedPageSizeInKB = U32Kilobytes(0);
+
+        stats.add("Page Fault Count", 0);
+        stats.add("PeakWorkingSetSize KB", 0);
+        stats.add("WorkingSetSize KB", 0);
+        stats.add("QuotaPeakPagedPoolUsage KB", 0);
+        stats.add("QuotaPagedPoolUsage KB", 0);
+        stats.add("QuotaPeakNonPagedPoolUsage KB", 0);
+        stats.add("QuotaNonPagedPoolUsage KB", 0);
+        stats.add("PagefileUsage KB", 0);
+        stats.add("PeakPagefileUsage KB", 0);
+        stats.add("PrivateUsage KB", 0);
+    }
 
 #elif LL_DARWIN
 
diff --git a/indra/llcommon/llsys.h b/indra/llcommon/llsys.h
index c8ff4dd98a..91fa2754ab 100644
--- a/indra/llcommon/llsys.h
+++ b/indra/llcommon/llsys.h
@@ -4,7 +4,7 @@
  *
  * $LicenseInfo:firstyear=2001&license=viewerlgpl$
  * Second Life Viewer Source Code
- * Copyright (C) 2010, Linden Research, Inc.
+ * Copyright (C) 2026, 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
@@ -134,11 +134,12 @@ public:
     static U32Kilobytes getHardwareMemSize(); // Because some Mac linkers won't let us reference extern gSysMemory from a different lib.
 #endif
 
-    //get the available memory in KiloBytes.
-    static void getAvailableMemoryKB(U32Kilobytes& avail_mem_kb);
+    // Updates LLMemory's values.
+    static void updateAvailableMemory();
 
     // Retrieve a map of memory statistics. The keys of the map are platform-
-    // dependent. The values are in kilobytes to try to avoid integer overflow.
+    // dependent.
+    // On Windows updates LLMemory values.
     LLSD getStatsMap() const;
 
     // Re-fetch memory data (as reported by stream() and getStatsMap()) from the
diff --git a/indra/llcommon/llwatchdog.cpp b/indra/llcommon/llwatchdog.cpp
index 66b565c763..886f19366c 100644
--- a/indra/llcommon/llwatchdog.cpp
+++ b/indra/llcommon/llwatchdog.cpp
@@ -116,6 +116,11 @@ bool LLWatchdogTimeout::isAlive() const
     return (mTimer.getStarted() && !mTimer.hasExpired());
 }
 
+bool LLWatchdogTimeout::started() const
+{
+    return mTimer.getStarted();
+}
+
 void LLWatchdogTimeout::reset()
 {
     mTimer.setTimerExpirySec(mTimeout);
diff --git a/indra/llcommon/llwatchdog.h b/indra/llcommon/llwatchdog.h
index f138fbccb0..d55bf434f3 100644
--- a/indra/llcommon/llwatchdog.h
+++ b/indra/llcommon/llwatchdog.h
@@ -47,6 +47,7 @@ public:
     // This may mean that resources used by
     // isAlive and other method may need synchronization.
     virtual bool isAlive() const = 0;
+    virtual bool started() const = 0;
     virtual void reset() = 0;
     virtual void start();
     virtual void stop();
@@ -66,6 +67,7 @@ public:
     virtual ~LLWatchdogTimeout();
 
     bool isAlive() const override;
+    bool started() const override;
     void reset() override;
     void start() override { start(""); }
     void stop() override;