diff -r de91a2f25c7e -r 2d127394260e src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp
--- a/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp	Thu May 27 09:54:07 2010 -0700
+++ b/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp	Thu May 27 18:01:56 2010 -0700
@@ -3644,7 +3644,7 @@
   do {
     free_words = r->free()/HeapWordSize;
     // If there's too little space, no one can allocate, so we're done.
-    if (free_words < (size_t)oopDesc::header_size()) return;
+    if (free_words < CollectedHeap::min_fill_size()) return;
     // Otherwise, try to claim it.
     block = r->par_allocate(free_words);
   } while (block == NULL);