Revert heapcount and enable CPU Groups to fix Ubuntu FPE (#22861)

1 files changed, 23 insertions, 1 deletions

diff --git a/src/gc/gc.cpp b/src/gc/gc.cpp
index d5a18b1785..95fe21ccb6 100644
--- a/src/gc/gc.cpp
+++ b/src/gc/gc.cpp
@@ -34206,7 +34206,10 @@ HRESULT GCHeap::Initialize()
 #ifdef MULTIPLE_HEAPS
     nhp_from_config = static_cast<uint32_t>(GCConfig::GetHeapCount());
     
-    uint32_t nhp_from_process = GCToOSInterface::GetCurrentProcessCpuCount();
+    // GetCurrentProcessCpuCount only returns up to 64 procs.
+    uint32_t nhp_from_process = GCToOSInterface::CanEnableGCCPUGroups() ?
+                                GCToOSInterface::GetTotalProcessorCount():
+                                GCToOSInterface::GetCurrentProcessCpuCount();
 
     if (nhp_from_config)
     {
@@ -34237,6 +34240,20 @@ HRESULT GCHeap::Initialize()
             {
                 pmask &= smask;
 
+#ifdef FEATURE_PAL
+                // GetCurrentProcessAffinityMask can return pmask=0 and smask=0 on
+                // systems with more than 1 NUMA node. The pmask decides the
+                // number of GC heaps to be used and the processors they are
+                // affinitized with. So pmask is now set to reflect that 64
+                // processors are available to begin with. The actual processors in
+                // the system may be lower and are taken into account before
+                // finalizing the number of heaps.
+                if (!pmask)
+                {
+                    pmask = SIZE_T_MAX;
+                }
+#endif // FEATURE_PAL
+
                 if (gc_thread_affinity_mask)
                 {
                     pmask &= gc_thread_affinity_mask;
@@ -34253,6 +34270,11 @@ HRESULT GCHeap::Initialize()
                 }
 
                 nhp = min (nhp, set_bits_in_pmask);
+
+#ifdef FEATURE_PAL
+                // Limit the GC heaps to the number of processors available in the system.
+                nhp = min (nhp, GCToOSInterface::GetTotalProcessorCount());
+#endif // FEATURE_PAL
             }
             else
             {