Index: /trunk/src/VBox/Runtime/common/alloc/memcache.cpp
===================================================================
--- /trunk/src/VBox/Runtime/common/alloc/memcache.cpp	(revision 55255)
+++ /trunk/src/VBox/Runtime/common/alloc/memcache.cpp	(revision 55256)
@@ -350,11 +350,12 @@
 DECL_FORCE_INLINE(int32_t) rtMemCacheGrabObj(PRTMEMCACHEPAGE pPage)
 {
-    int32_t cFreeNew = ASMAtomicDecS32(&pPage->cFree);
-    if (cFreeNew < 0)
-    {
+    if (ASMAtomicUoReadS32(&pPage->cFree) > 0)
+    {
+        int32_t cFreeNew = ASMAtomicDecS32(&pPage->cFree);
+        if (cFreeNew >= 0)
+            return cFreeNew;
         ASMAtomicIncS32(&pPage->cFree);
-        return -1;
-    }
-    return cFreeNew;
+    }
+    return -1;
 }
 
@@ -414,5 +415,5 @@
      * Grab a free object at the page level.
      */
-    PRTMEMCACHEPAGE pPage = ASMAtomicReadPtrT(&pThis->pPageHint, PRTMEMCACHEPAGE);
+    PRTMEMCACHEPAGE pPage = ASMAtomicUoReadPtrT(&pThis->pPageHint, PRTMEMCACHEPAGE);
     int32_t iObj = pPage ? rtMemCacheGrabObj(pPage) : -1;
     if (iObj < 0)