Allow overriding processor count via configuration setting

src/coreclr/classlibnative/bcltype/system.cpp

@@ -182,21 +182,7 @@ INT32 QCALLTYPE SystemNative::GetProcessorCount()
 
     BEGIN_QCALL;
 
-#ifndef TARGET_UNIX
-    CPUGroupInfo::EnsureInitialized();
-
-    if (CPUGroupInfo::CanEnableThreadUseAllCpuGroups())
-    {
-        processorCount = CPUGroupInfo::GetNumActiveProcessors();
-    }
-    else
-#endif // !TARGET_UNIX
-    {
-        // This similar to GetSystemInfo() + dwNumberOfProcessors except:
-        // - GetCurrentProcessCpuCount() tries to take into account the processor affinity mask where applicable
-        // - GetCurrentProcessCpuCount() on Unixes tries to take into account cgroups CPU quota limits where applicable
-        processorCount = GetCurrentProcessCpuCount();
-    }
+    processorCount = GetCurrentProcessCpuCount();
 
     END_QCALL;
 

src/coreclr/dlls/mscordac/mscordac_unixexports.src

@@ -29,6 +29,7 @@ nativeStringResourceTable_mscorrc
 #PAL_free
 #PAL_fwprintf
 #PAL_GetLogicalCpuCountFromOS
+#PAL_GetTotalCpuCount
 #PAL_GetNumaProcessorNode
 #PAL_get_stdout
 #PAL_get_stderr

src/coreclr/gc/env/gcenv.ee.h

@@ -91,6 +91,7 @@ class GCToEEInterface
     static void VerifySyncTableEntry();
     static void UpdateGCEventStatus(int publicLevel, int publicKeywords, int privateLevel, int privateKeywords);
     static void LogStressMsg(unsigned level, unsigned facility, const StressLogMsg &msg);
+    static uint32_t GetCurrentProcessCpuCount();
 };
 
 #endif // __GCENV_EE_H__

src/coreclr/gc/env/gcenv.os.h

@@ -388,11 +388,6 @@ class GCToOSInterface
     //  Size of the cache
     static size_t GetCacheSizePerLogicalCpu(bool trueSize = true);
 
-    // Get number of processors assigned to the current process
-    // Return:
-    //  The number of processors
-    static uint32_t GetCurrentProcessCpuCount();
-
     // Sets the calling thread's affinity to only run on the processor specified.
     // Parameters:
     //  procNo - The requested affinity for the calling thread.

src/coreclr/gc/gc.cpp

@@ -41280,7 +41280,7 @@ HRESULT GCHeap::Initialize()
 
     nhp_from_config = static_cast<uint32_t>(GCConfig::GetHeapCount());
 
-    g_num_active_processors = GCToOSInterface::GetCurrentProcessCpuCount();
+    g_num_active_processors = GCToEEInterface::GetCurrentProcessCpuCount();
 
     if (nhp_from_config)
     {
@@ -41292,7 +41292,7 @@ HRESULT GCHeap::Initialize()
     nhp = ((nhp_from_config == 0) ? g_num_active_processors : nhp_from_config);
 
     nhp = min (nhp, MAX_SUPPORTED_CPUS);
-#ifndef FEATURE_REDHAWK
+
     gc_heap::gc_thread_no_affinitize_p = (gc_heap::heap_hard_limit ? 
         !affinity_config_specified_p : (GCConfig::GetNoAffinitize() != 0));
 
@@ -41304,12 +41304,7 @@ HRESULT GCHeap::Initialize()
         {
             nhp = min(nhp, num_affinitized_processors);
         }
-#ifndef TARGET_WINDOWS
-        // Limit the GC heaps to the number of processors available in the system.
-        nhp = min (nhp, GCToOSInterface::GetTotalProcessorCount());
-#endif // !TARGET_WINDOWS
     }
-#endif //!FEATURE_REDHAWK
 #endif //MULTIPLE_HEAPS
 
     size_t seg_size = 0;

src/coreclr/gc/gcenv.ee.standalone.inl

@@ -301,4 +301,9 @@ inline void GCToEEInterface::LogStressMsg(unsigned level, unsigned facility, con
     g_theGCToCLR->LogStressMsg(level, facility, msg);
 }
 
+inline uint32_t GCToEEInterface::GetCurrentProcessCpuCount()
+{
+    return g_theGCToCLR->GetCurrentProcessCpuCount();
+}
+
 #endif // __GCTOENV_EE_STANDALONE_INL__

src/coreclr/gc/gcinterface.ee.h

@@ -426,6 +426,9 @@ class IGCToCLR {
 
     virtual
     void LogStressMsg(unsigned level, unsigned facility, const StressLogMsg& msg) = 0;
+
+    virtual
+    uint32_t GetCurrentProcessCpuCount() = 0;
 };
 
 #endif // _GCINTERFACE_EE_H_

src/coreclr/gc/handletablecache.cpp

@@ -18,7 +18,7 @@
 #undef Sleep
 #endif // Sleep
 
-#include "env/gcenv.os.h"
+#include "gc.h"
 
 #include "handletablepriv.h"
 
@@ -56,7 +56,7 @@ void SpinUntil(void *pCond, BOOL fNonZero)
 #endif //_DEBUG
 
     // on MP machines, allow ourselves some spin time before sleeping
-    static uint32_t uNonSleepSpins = 8 * (GCToOSInterface::GetCurrentProcessCpuCount() - 1);
+    static uint32_t uNonSleepSpins = 8 * (GCToEEInterface::GetCurrentProcessCpuCount() - 1);
 
     // spin until the specificed condition is met
     while ((*(uintptr_t *)pCond != 0) != (fNonZero != 0))

src/coreclr/gc/sample/gcenv.ee.cpp

@@ -291,7 +291,6 @@ bool GCToEEInterface::GetStringConfigValue(const char* privateKey, const char* p
 
 void GCToEEInterface::FreeStringConfigValue(const char *value)
 {
-
 }
 
 bool GCToEEInterface::IsGCThread()
@@ -341,7 +340,6 @@ inline bool GCToEEInterface::AnalyzeSurvivorsRequested(int condemnedGeneration)
 
 inline void GCToEEInterface::AnalyzeSurvivorsFinished(size_t gcIndex, int condemnedGeneration, uint64_t promoted_bytes, void (*reportGenerationBounds)())
 {
-
 }
 
 void GCToEEInterface::VerifySyncTableEntry()
@@ -351,3 +349,8 @@ void GCToEEInterface::VerifySyncTableEntry()
 void GCToEEInterface::UpdateGCEventStatus(int currentPublicLevel, int currentPublicKeywords, int currentPrivateLevel, int currentPrivateKeywords)
 {
 }
+
+uint32_t GCToEEInterface::GetCurrentProcessCpuCount()
+{
+    return GCToOSInterface::GetTotalProcessorCount();
+}