7041501: NUMA: Expand the old gen more aggressively

Summary: Expand the old gen in bigger increments
Reviewed-by: jmasa

src/share/vm/gc_implementation/parallelScavenge/psOldGen.cpp

@@ -224,6 +224,12 @@ void PSOldGen::expand(size_t bytes) {
   const size_t alignment = virtual_space()->alignment();
   size_t aligned_bytes  = align_size_up(bytes, alignment);
   size_t aligned_expand_bytes = align_size_up(MinHeapDeltaBytes, alignment);
+
+  if (UseNUMA) {
+    // With NUMA we use round-robin page allocation for the old gen. Expand by at least
+    // providing a page per lgroup. Alignment is larger or equal to the page size.
+    aligned_expand_bytes = MAX2(aligned_expand_bytes, alignment * os::numa_get_groups_num());
+  }
   if (aligned_bytes == 0){
     // The alignment caused the number of bytes to wrap.  An expand_by(0) will
     // return true with the implication that and expansion was done when it

src/share/vm/runtime/arguments.cpp

@@ -1423,6 +1423,11 @@ void Arguments::set_parallel_gc_flags() {
       }
     }
   }
+  if (UseNUMA) {
+    if (FLAG_IS_DEFAULT(MinHeapDeltaBytes)) {
+      FLAG_SET_DEFAULT(MinHeapDeltaBytes, 64*M);
+    }
+  }
 }
 
 void Arguments::set_g1_gc_flags() {