8022817: CMS should not shrink if compaction was not done
Reviewed-by: ysr, mgerdin
diff --git a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp
index fe53388..04b550c 100644
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp
@@ -3460,7 +3460,9 @@
void ConcurrentMarkSweepGeneration::shrink(size_t bytes) {
assert_locked_or_safepoint(Heap_lock);
size_t size = ReservedSpace::page_align_size_down(bytes);
- if (size > 0) {
+ // Only shrink if a compaction was done so that all the free space
+ // in the generation is in a contiguous block at the end.
+ if (size > 0 && did_compact()) {
shrink_by(size);
}
}
@@ -8696,9 +8698,10 @@
assert(inFreeRange(), "Should only be called if currently in a free range.");
HeapWord* const eob = ((HeapWord*)fc) + chunk_size;
assert(_sp->used_region().contains(eob - 1),
- err_msg("eob = " PTR_FORMAT " out of bounds wrt _sp = [" PTR_FORMAT "," PTR_FORMAT ")"
+ err_msg("eob = " PTR_FORMAT " eob-1 = " PTR_FORMAT " _limit = " PTR_FORMAT
+ " out of bounds wrt _sp = [" PTR_FORMAT "," PTR_FORMAT ")"
" when examining fc = " PTR_FORMAT "(" SIZE_FORMAT ")",
- _limit, _sp->bottom(), _sp->end(), fc, chunk_size));
+ eob, eob-1, _limit, _sp->bottom(), _sp->end(), fc, chunk_size));
if (eob >= _limit) {
assert(eob == _limit || fc->is_free(), "Only a free chunk should allow us to cross over the limit");
if (CMSTraceSweeper) {
