diff --git a/rts/posix/OSMem.c b/rts/posix/OSMem.c
index 4328d9d2622e53c2cbd493d12b3cd072c32d7115..21d4e5443ca61b314a4fb225fc8ebaab286ef384 100644
--- a/rts/posix/OSMem.c
+++ b/rts/posix/OSMem.c
@@ -263,6 +263,26 @@ W_ getPageSize (void)
     }
 }
 
+/* Returns 0 if physical memory size cannot be identified */
+StgWord64 getPhysicalMemorySize (void)
+{
+    static StgWord64 physMemSize = 0;
+    if (!physMemSize) {
+        long ret;
+        W_ pageSize = getPageSize();
+
+        ret = sysconf(_SC_PHYS_PAGES);
+        if (ret == -1) {
+#if defined(DEBUG)
+            errorBelch("warning: getPhysicsMemorySize: cannot get physical memory size");
+#endif
+            return 0;
+        }
+        physMemSize = ret * pageSize;
+    }
+    return physMemSize;
+}
+
 void setExecutable (void *p, W_ len, rtsBool exec)
 {
     StgWord pageSize = getPageSize();
diff --git a/rts/sm/OSMem.h b/rts/sm/OSMem.h
index a0d615b4249d9388203dabe084f8da09c0718cc6..db704fc78bb3b1d03815e33cf3137d6967ac60fd 100644
--- a/rts/sm/OSMem.h
+++ b/rts/sm/OSMem.h
@@ -17,6 +17,7 @@ void osFreeMBlocks(char *addr, nat n);
 void osReleaseFreeMemory(void);
 void osFreeAllMBlocks(void);
 W_ getPageSize (void);
+StgWord64 getPhysicalMemorySize (void);
 void setExecutable (void *p, W_ len, rtsBool exec);
 
 #include "EndPrivate.h"
diff --git a/rts/win32/OSMem.c b/rts/win32/OSMem.c
index 218b25df13016c27d22be2b535f00a289d7add7b..f350076c9404d3888add1e663a225d883d2205ee 100644
--- a/rts/win32/OSMem.c
+++ b/rts/win32/OSMem.c
@@ -378,6 +378,24 @@ W_ getPageSize (void)
     }
 }
 
+/* Returns 0 if physical memory size cannot be identified */
+StgWord64 getPhysicalMemorySize (void)
+{
+    static StgWord64 physMemSize = 0;
+    if (!physMemSize) {
+        MEMORYSTATUSEX status;
+        status.dwLength = sizeof(status);
+        if (!GlobalMemoryStatusEx(&status)) {
+#if defined(DEBUG)
+            errorBelch("warning: getPhysicalMemorySize: cannot get physical memory size");
+#endif
+            return 0;
+        }
+        physMemSize = status.ullTotalPhys;
+    }
+    return physMemSize;
+}
+
 void setExecutable (void *p, W_ len, rtsBool exec)
 {
     DWORD dwOldProtect = 0;