Add CGroup CFS CPU limit support (#12797)

1 files changed, 28 insertions, 17 deletions

diff --git a/src/utilcode/util.cpp b/src/utilcode/util.cpp
index f0c6b1c96e..8e9979efc2 100644
--- a/src/utilcode/util.cpp
+++ b/src/utilcode/util.cpp
@@ -1269,32 +1269,43 @@ int GetCurrentProcessCpuCount()
     if (cCPUs != 0)
         return cCPUs;
 
+    int count = 0;
     DWORD_PTR pmask, smask;
 
     if (!GetProcessAffinityMask(GetCurrentProcess(), &pmask, &smask))
-        return 1;
+    {
+        count = 1;
+    }
+    else
+    {
+        pmask &= smask;
 
-    pmask &= smask;
+        while (pmask)
+        {
+            pmask &= (pmask - 1);
+            count++;
+        }
 
-    int count = 0;
-    while (pmask)
-    {
-        pmask &= (pmask - 1);
-        count++;
+        // GetProcessAffinityMask can return pmask=0 and smask=0 on systems with more
+        // than 64 processors, which would leave us with a count of 0.  Since the GC
+        // expects there to be at least one processor to run on (and thus at least one
+        // heap), we'll return 64 here if count is 0, since there are likely a ton of
+        // processors available in that case.  The GC also cannot (currently) handle
+        // the case where there are more than 64 processors, so we will return a
+        // maximum of 64 here.
+        if (count == 0 || count > 64)
+            count = 64;
     }
 
-    // GetProcessAffinityMask can return pmask=0 and smask=0 on systems with more
-    // than 64 processors, which would leave us with a count of 0.  Since the GC
-    // expects there to be at least one processor to run on (and thus at least one
-    // heap), we'll return 64 here if count is 0, since there are likely a ton of
-    // processors available in that case.  The GC also cannot (currently) handle
-    // the case where there are more than 64 processors, so we will return a
-    // maximum of 64 here.
-    if (count == 0 || count > 64)
-        count = 64;
+#ifdef FEATURE_PAL
+    uint32_t cpuLimit;
+
+    if (PAL_GetCpuLimit(&cpuLimit) && cpuLimit < count)
+        count = cpuLimit;
+#endif
 
     cCPUs = count;
-            
+
     return count;
 }