Adjust regions range dynamically based on memory limits (dotnet#71164)

GrabYourPitchforks · Jun 30, 2022 · bb36771 · bb36771
1 parent 7cf661d
commit bb36771
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Showing 2 changed files with 18 additions and 6 deletions.
diff --git a/src/coreclr/gc/gc.cpp b/src/coreclr/gc/gc.cpp
@@ -43855,11 +43855,6 @@ HRESULT GCHeap::Initialize()
     {
         gc_heap::total_physical_mem = GCToOSInterface::GetPhysicalMemoryLimit (&gc_heap::is_restricted_physical_mem);
     }
-
-#ifdef USE_REGIONS
-    gc_heap::regions_range = (size_t)GCConfig::GetGCRegionRange();
-#endif //USE_REGIONS
-
 #ifdef HOST_64BIT
     gc_heap::heap_hard_limit = (size_t)GCConfig::GetGCHeapHardLimit();
     gc_heap::heap_hard_limit_oh[soh] = (size_t)GCConfig::GetGCHeapHardLimitSOH();
@@ -43948,6 +43943,23 @@ HRESULT GCHeap::Initialize()
         return CLR_E_GC_LARGE_PAGE_MISSING_HARD_LIMIT;
     }
 
+#ifdef USE_REGIONS
+    gc_heap::regions_range = (size_t)GCConfig::GetGCRegionRange();
+    if (gc_heap::regions_range == 0)
+    {
+        if (gc_heap::heap_hard_limit)
+        {
+            gc_heap::regions_range = 2 * gc_heap::heap_hard_limit;
+        }
+        else
+        {
+            gc_heap::regions_range = max(((size_t)256 * 1024 * 1024 * 1024), (size_t)(2 * gc_heap::total_physical_mem));
+        }
+        gc_heap::regions_range = align_on_page(gc_heap::regions_range);
+    }
+    // TODO: Set config after config API is merged.
+#endif //USE_REGIONS
+
 #endif //HOST_64BIT
 
     uint32_t nhp = 1;

diff --git a/src/coreclr/gc/gcconfig.h b/src/coreclr/gc/gcconfig.h
@@ -103,7 +103,7 @@ class GCConfigStringHolder
     INT_CONFIG   (GCHeapHardLimit,        "GCHeapHardLimit",        "System.GC.HeapHardLimit",        0,                 "Specifies a hard limit for the GC heap")                                                 \
     INT_CONFIG   (GCHeapHardLimitPercent, "GCHeapHardLimitPercent", "System.GC.HeapHardLimitPercent", 0,                 "Specifies the GC heap usage as a percentage of the total memory")                        \
     INT_CONFIG   (GCTotalPhysicalMemory,  "GCTotalPhysicalMemory",  NULL,                             0,                 "Specifies what the GC should consider to be total physical memory")                      \
-    INT_CONFIG   (GCRegionRange,          "GCRegionRange",          NULL,                             274877906944L,     "Specifies the range for the GC heap")                                                    \
+    INT_CONFIG   (GCRegionRange,          "GCRegionRange",          NULL,                             0,                 "Specifies the range for the GC heap")                                                    \
     INT_CONFIG   (GCRegionSize,           "GCRegionSize",           NULL,                             4194304,           "Specifies the size for a basic GC region")                                               \
     STRING_CONFIG(LogFile,                "GCLogFile",              NULL,                                                "Specifies the name of the GC log file")                                                  \
     STRING_CONFIG(ConfigLogFile,          "GCConfigLogFile",        NULL,                                                "Specifies the name of the GC config log file")                                           \