diff -r 22b8d3d181d9 -r 2e6857353b2c src/share/vm/gc_implementation/shared/parGCAllocBuffer.cpp
--- a/src/share/vm/gc_implementation/shared/parGCAllocBuffer.cpp	Wed Oct 03 20:31:41 2012 +0200
+++ b/src/share/vm/gc_implementation/shared/parGCAllocBuffer.cpp	Thu Oct 04 10:04:13 2012 -0700
@@ -87,7 +87,7 @@
 // Compute desired plab size and latch result for later
 // use. This should be called once at the end of parallel
 // scavenge; it clears the sensor accumulators.
-void PLABStats::adjust_desired_plab_sz() {
+void PLABStats::adjust_desired_plab_sz(uint no_of_gc_workers) {
   assert(ResizePLAB, "Not set");
   if (_allocated == 0) {
     assert(_unused == 0,
@@ -107,7 +107,7 @@
     target_refills = 1;
   }
   _used = _allocated - _wasted - _unused;
-  size_t plab_sz = _used/(target_refills*ParallelGCThreads);
+  size_t plab_sz = _used/(target_refills*no_of_gc_workers);
   if (PrintPLAB) gclog_or_tty->print(" (plab_sz = %d ", plab_sz);
   // Take historical weighted average
   _filter.sample(plab_sz);