Add option GCTrimYoungestKeepPercent to specifies the percent of youn…

…gest gen to keep during trimming
dotnet · Jan 31, 2025 · 8d4aef9 · 8d4aef9
1 parent 847a8c2
commit 8d4aef9
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Showing 2 changed files with 7 additions and 1 deletion.
diff --git a/src/coreclr/gc/gc.cpp b/src/coreclr/gc/gc.cpp
@@ -44545,10 +44545,15 @@ void gc_heap::trim_youngest_desired_low_memory()
 {
     if (g_low_memory_status)
     {
+        int keep_percent = static_cast<int>(GCConfig::GetGCTrimYoungestKeepPercent());
+        if ((keep_percent <= 0) || (keep_percent > 100))
+        {
+            keep_percent = 10;
+        }
         size_t committed_mem = committed_size();
         dynamic_data* dd = dynamic_data_of (0);
         size_t current = dd_desired_allocation (dd);
-        size_t candidate = max (Align ((committed_mem / 10), get_alignment_constant(FALSE)), dd_min_size (dd));
+        size_t candidate = max (Align ((size_t)((committed_mem / 100.0) * keep_percent), get_alignment_constant(FALSE)), dd_min_size (dd));
 
         dd_desired_allocation (dd) = min (current, candidate);
     }

diff --git a/src/coreclr/gc/gcconfig.h b/src/coreclr/gc/gcconfig.h
@@ -96,6 +96,7 @@ class GCConfigStringHolder
     STRING_CONFIG(GCHeapAffinitizeRanges,    "GCHeapAffinitizeRanges",    "System.GC.HeapAffinitizeRanges",                        "Specifies list of processors for Server GC threads. The format is a comma separated "     \
                                                                                                                                           "list of processor numbers or ranges of processor numbers. On Windows, each entry is "    \
                                                                                                                                           "prefixed by the CPU group number. Example: Unix - 1,3,5,7-9,12, Windows - 0:1,1:7-9")    \
+    INT_CONFIG   (GCTrimYoungestKeepPercent, "GCTrimYoungestKeepPercent", NULL,                                10,                 "Specifies the percent youngest gen to keep during trimming")                              \
     INT_CONFIG   (GCHighMemPercent,          "GCHighMemPercent",          "System.GC.HighMemoryPercent",       0,                  "The percent for GC to consider as high memory")                                           \
     INT_CONFIG   (GCProvModeStress,          "GCProvModeStress",          NULL,                                0,                  "Stress the provisional modes")                                                           \
     INT_CONFIG   (GCGen0MaxBudget,           "GCGen0MaxBudget",           NULL,                                0,                  "Specifies the largest gen0 allocation budget")                                           \