Use sysconf(_SC_NPROCESSORS_CONF) in PAL and GC ONLY on ARM and ARM64 (#5919)

Port https://github.com/dotnet/coreclr/pull/18289

2 files changed, 19 insertions, 25 deletions

diff --git a/src/Native/Runtime/unix/PalRedhawkUnix.cpp b/src/Native/Runtime/unix/PalRedhawkUnix.cpp
index d65007052..de3d296ae 100644
--- a/src/Native/Runtime/unix/PalRedhawkUnix.cpp
+++ b/src/Native/Runtime/unix/PalRedhawkUnix.cpp
@@ -94,6 +94,14 @@ using std::nullptr_t;
 #endif
 #endif // __APPLE__
 
+#if defined(_ARM_) || defined(_ARM64_)
+#define SYSCONF_GET_NUMPROCS       _SC_NPROCESSORS_CONF
+#define SYSCONF_GET_NUMPROCS_NAME "_SC_NPROCESSORS_CONF"
+#else
+#define SYSCONF_GET_NUMPROCS       _SC_NPROCESSORS_ONLN
+#define SYSCONF_GET_NUMPROCS_NAME "_SC_NPROCESSORS_ONLN"
+#endif
+
 #define PalRaiseFailFastException RaiseFailFastException
 
 #define FATAL_ASSERT(e, msg) \
@@ -834,17 +842,10 @@ bool QueryCacheSize()
 bool QueryLogicalProcessorCount()
 {
 #if HAVE_SYSCONF
-    int sysConfName;
-#if defined(_WASM_)
-    sysConfName = _SC_NPROCESSORS_ONLN;
-#else
-    sysConfName = _SC_NPROCESSORS_CONF;
-#endif
-
-    g_cLogicalCpus = sysconf(sysConfName);
+    g_cLogicalCpus = sysconf(SYSCONF_GET_NUMPROCS);
     if (g_cLogicalCpus < 1)
     {
-        ASSERT_UNCONDITIONALLY("sysconf failed for _SC_NPROCESSORS_CONF\n");
+        ASSERT_UNCONDITIONALLY("sysconf failed for " SYSCONF_GET_NUMPROCS_NAME "\n");
         return false;
     }
 #elif HAVE_SYSCTL
@@ -1275,16 +1276,10 @@ bool InitializeSystemInfo()
     int nrcpus = 0;
 
 #if HAVE_SYSCONF
-    int sysConfName;
-#if defined(_WASM_)
-    sysConfName = _SC_NPROCESSORS_ONLN;
-#else
-    sysConfName = _SC_NPROCESSORS_CONF;
-#endif
-    nrcpus = sysconf(sysConfName);
+    nrcpus = sysconf(SYSCONF_GET_NUMPROCS);
     if (nrcpus < 1)
     {
-        ASSERT_UNCONDITIONALLY("sysconf failed for _SC_NPROCESSORS_CONF\n");
+        ASSERT_UNCONDITIONALLY("sysconf failed for " SYSCONF_GET_NUMPROCS_NAME "\n");
         return false;
     }
 #elif HAVE_SYSCTL
diff --git a/src/Native/gc/unix/gcenv.unix.cpp b/src/Native/gc/unix/gcenv.unix.cpp
index dfddbaba3..819049b42 100644
--- a/src/Native/gc/unix/gcenv.unix.cpp
+++ b/src/Native/gc/unix/gcenv.unix.cpp
@@ -57,6 +57,12 @@ static_assert(sizeof(uint64_t) == 8, "unsigned long isn't 8 bytes");
 #include <errno.h>
 #include <unistd.h> // sysconf
 
+#if defined(_ARM_) || defined(_ARM64_)
+#define SYSCONF_GET_NUMPROCS _SC_NPROCESSORS_CONF
+#else
+#define SYSCONF_GET_NUMPROCS _SC_NPROCESSORS_ONLN
+#endif
+
 // The number of milliseconds in a second.
 static const int tccSecondsToMilliSeconds = 1000;
 
@@ -84,14 +90,7 @@ static pthread_mutex_t g_flushProcessWriteBuffersMutex;
 bool GCToOSInterface::Initialize()
 {
     // Calculate and cache the number of processors on this machine
-    int sysConfName;
-#if defined(_TARGET_WASM_)
-    sysConfName = _SC_NPROCESSORS_ONLN;
-#else
-    sysConfName = _SC_NPROCESSORS_CONF;
-#endif
-
-    int cpuCount = sysconf(sysConfName);
+    int cpuCount = sysconf(SYSCONF_GET_NUMPROCS);
     if (cpuCount == -1)
     {
         return false;