src/hotspot/share/gc/g1/g1RemSet.cpp

@@ -175,11 +175,11 @@
     void add_dirty_region(uint region) {
       if (_contains[region]) {
         return;
       }
 
-      bool marked_as_dirty = Atomic::cmpxchg(true, &_contains[region], false) == false;
+      bool marked_as_dirty = Atomic::cmpxchg(&_contains[region], false, true) == false;
       if (marked_as_dirty) {
         uint allocated = Atomic::add(&_cur_idx, 1u) - 1;
         _buffer[allocated] = region;
       }
     }

@@ -435,11 +435,11 @@
   inline bool claim_collection_set_region(uint region) {
     assert(region < _max_regions, "Tried to access invalid region %u", region);
     if (_collection_set_iter_state[region]) {
       return false;
     }
-    return !Atomic::cmpxchg(true, &_collection_set_iter_state[region], false);
+    return !Atomic::cmpxchg(&_collection_set_iter_state[region], false, true);
   }
 
   bool has_cards_to_scan(uint region) {
     assert(region < _max_regions, "Tried to access invalid region %u", region);
     return _card_table_scan_state[region] < HeapRegion::CardsPerRegion;

@@ -1135,11 +1135,11 @@
     // We schedule flushing the remembered sets of humongous fast reclaim candidates
     // onto the card table first to allow the remaining parallelized tasks hide it.
     if (_initial_evacuation &&
         p->fast_reclaim_humongous_candidates() > 0 &&
         !_fast_reclaim_handled &&
-        !Atomic::cmpxchg(true, &_fast_reclaim_handled, false)) {
+        !Atomic::cmpxchg(&_fast_reclaim_handled, false, true)) {
 
       G1GCParPhaseTimesTracker x(p, G1GCPhaseTimes::MergeER, worker_id);
 
       G1FlushHumongousCandidateRemSets cl(_scan_state);
       g1h->heap_region_iterate(&cl);