6862661: G1: _gc_alloc_region_counts is not updated properly after 6604422
Summary: Implementation of RFE 6604422 (G1: re-use half-promoted regions) introduced incorrect _gc_alloc_region_counts updates which effectively disabled survivor spaces.
Reviewed-by: johnc, jmasa, tonyp
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Thu Jul 16 12:38:26 2009 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Wed Jul 22 02:46:55 2009 -0700
@@ -2981,6 +2981,7 @@
for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
assert(_gc_alloc_regions[ap] == NULL, "invariant");
+ assert(_gc_alloc_region_counts[ap] == 0, "invariant");
// Create new GC alloc regions.
HeapRegion* alloc_region = _retained_gc_alloc_regions[ap];
@@ -3009,6 +3010,9 @@
if (alloc_region == NULL) {
// we will get a new GC alloc region
alloc_region = newAllocRegionWithExpansion(ap, 0);
+ } else {
+ // the region was retained from the last collection
+ ++_gc_alloc_region_counts[ap];
}
if (alloc_region != NULL) {
@@ -3047,11 +3051,11 @@
for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
HeapRegion* r = _gc_alloc_regions[ap];
_retained_gc_alloc_regions[ap] = NULL;
+ _gc_alloc_region_counts[ap] = 0;
if (r != NULL) {
// we retain nothing on _gc_alloc_regions between GCs
set_gc_alloc_region(ap, NULL);
- _gc_alloc_region_counts[ap] = 0;
if (r->is_empty()) {
// we didn't actually allocate anything in it; let's just put