diff --git a/src/share/vm/gc_implementation/shared/vmGCOperations.cpp b/src/share/vm/gc_implementation/shared/vmGCOperations.cpp index c230275275afbf09492eb2eddf3bb68f6af63270..17d18db32da54433ebf9d26edfa1a78fc1a6ba14 100644 --- a/src/share/vm/gc_implementation/shared/vmGCOperations.cpp +++ b/src/share/vm/gc_implementation/shared/vmGCOperations.cpp @@ -115,11 +115,25 @@ bool VM_GC_HeapInspection::skip_operation() const { void VM_GC_HeapInspection::doit() { HandleMark hm; CollectedHeap* ch = Universe::heap(); + ch->ensure_parsability(false); // must happen, even if collection does + // not happen (e.g. due to GC_locker) if (_full_gc) { - ch->collect_as_vm_thread(GCCause::_heap_inspection); - } else { - // make the heap parsable (no need to retire TLABs) - ch->ensure_parsability(false); + // The collection attempt below would be skipped anyway if + // the gc locker is held. The following dump may then be a tad + // misleading to someone expecting only live objects to show + // up in the dump (see CR 6944195). Just issue a suitable warning + // in that case and do not attempt to do a collection. + // The latter is a subtle point, because even a failed attempt + // to GC will, in fact, induce one in the future, which we + // probably want to avoid in this case because the GC that we may + // be about to attempt holds value for us only + // if it happens now and not if it happens in the eventual + // future. + if (GC_locker::is_active()) { + warning("GC locker is held; pre-dump GC was skipped"); + } else { + ch->collect_as_vm_thread(GCCause::_heap_inspection); + } } HeapInspection::heap_inspection(_out, _need_prologue /* need_prologue */); }