SL-18154 WIP -- CPU sampling (AMD uProf) profile guided optimizations to reduce CPU usage of background threads.

1 files changed, 17 insertions, 1 deletions

diff --git a/indra/llwindow/llwindowwin32.cpp b/indra/llwindow/llwindowwin32.cpp
index c0d3424141..be5af8240f 100644
--- a/indra/llwindow/llwindowwin32.cpp
+++ b/indra/llwindow/llwindowwin32.cpp
@@ -467,7 +467,6 @@ LLWindowWin32::LLWindowWin32(LLWindowCallbacks* callbacks,
         // process deprioritization during profiles
     // force high thread priority
     HANDLE hProcess = GetCurrentProcess();
-    HANDLE hThread = GetCurrentThread();
 
     if (hProcess)
     {
@@ -484,6 +483,20 @@ LLWindowWin32::LLWindowWin32(LLWindowCallbacks* callbacks,
             }
         }
     }
+#endif
+
+#if 0  // this is also probably a bad idea, but keep it in your back pocket for getting main thread off of background thread cores (see also LLThread::threadRun)
+    HANDLE hThread = GetCurrentThread();
+
+    SYSTEM_INFO sysInfo;
+
+    GetSystemInfo(&sysInfo);
+    U32 core_count = sysInfo.dwNumberOfProcessors;
+
+    if (max_cores != 0)
+    {
+        core_count = llmin(core_count, max_cores);
+    }
 
     if (hThread)
     {
@@ -499,6 +512,9 @@ LLWindowWin32::LLWindowWin32(LLWindowCallbacks* callbacks,
             {
                 LL_INFOS() << "Failed to set thread priority: " << std::hex << GetLastError() << LL_ENDL;
             }
+
+            // tell main thread to prefer core 0
+            SetThreadIdealProcessor(hThread, 0);
         }
     }
 #endif