diff src/share/vm/gc_implementation/g1/concurrentMark.cpp @ 2173:97ba643ea3ed

7014261: G1: RSet-related failures Summary: A race between the concurrent cleanup thread and the VM thread while it is processing the "expanded sparse table list" causes both threads to try to free the same sparse table entry and either causes one of the threads to fail or leaves the entry in an inconsistent state. The solution is purge all entries on the expanded list that correspond go regions that are being cleaned up. Reviewed-by: brutisso, johnc
author tonyp
date Tue, 25 Jan 2011 17:58:19 -0500
parents 0fa27f37d4d4
children 81668b1f4877
line wrap: on
line diff
--- a/src/share/vm/gc_implementation/g1/concurrentMark.cpp	Fri Jan 21 11:30:22 2011 -0500
+++ b/src/share/vm/gc_implementation/g1/concurrentMark.cpp	Tue Jan 25 17:58:19 2011 -0500
@@ -1500,21 +1500,19 @@
   size_t _max_live_bytes;
   size_t _regions_claimed;
   size_t _freed_bytes;
-  FreeRegionList _local_cleanup_list;
-  HumongousRegionSet _humongous_proxy_set;
+  FreeRegionList* _local_cleanup_list;
+  HumongousRegionSet* _humongous_proxy_set;
+  HRRSCleanupTask* _hrrs_cleanup_task;
   double _claimed_region_time;
   double _max_region_time;
 
 public:
   G1NoteEndOfConcMarkClosure(G1CollectedHeap* g1,
-                             int worker_num);
+                             int worker_num,
+                             FreeRegionList* local_cleanup_list,
+                             HumongousRegionSet* humongous_proxy_set,
+                             HRRSCleanupTask* hrrs_cleanup_task);
   size_t freed_bytes() { return _freed_bytes; }
-  FreeRegionList* local_cleanup_list() {
-    return &_local_cleanup_list;
-  }
-  HumongousRegionSet* humongous_proxy_set() {
-    return &_humongous_proxy_set;
-  }
 
   bool doHeapRegion(HeapRegion *r);
 
@@ -1541,7 +1539,12 @@
 
   void work(int i) {
     double start = os::elapsedTime();
-    G1NoteEndOfConcMarkClosure g1_note_end(_g1h, i);
+    FreeRegionList local_cleanup_list("Local Cleanup List");
+    HumongousRegionSet humongous_proxy_set("Local Cleanup Humongous Proxy Set");
+    HRRSCleanupTask hrrs_cleanup_task;
+    G1NoteEndOfConcMarkClosure g1_note_end(_g1h, i, &local_cleanup_list,
+                                           &humongous_proxy_set,
+                                           &hrrs_cleanup_task);
     if (G1CollectedHeap::use_parallel_gc_threads()) {
       _g1h->heap_region_par_iterate_chunked(&g1_note_end, i,
                                             HeapRegion::NoteEndClaimValue);
@@ -1553,15 +1556,17 @@
     // Now update the lists
     _g1h->update_sets_after_freeing_regions(g1_note_end.freed_bytes(),
                                             NULL /* free_list */,
-                                            g1_note_end.humongous_proxy_set(),
+                                            &humongous_proxy_set,
                                             true /* par */);
     {
       MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag);
       _max_live_bytes += g1_note_end.max_live_bytes();
       _freed_bytes += g1_note_end.freed_bytes();
 
-      _cleanup_list->add_as_tail(g1_note_end.local_cleanup_list());
-      assert(g1_note_end.local_cleanup_list()->is_empty(), "post-condition");
+      _cleanup_list->add_as_tail(&local_cleanup_list);
+      assert(local_cleanup_list.is_empty(), "post-condition");
+
+      HeapRegionRemSet::finish_cleanup_task(&hrrs_cleanup_task);
     }
     double end = os::elapsedTime();
     if (G1PrintParCleanupStats) {
@@ -1602,13 +1607,17 @@
 
 G1NoteEndOfConcMarkClosure::
 G1NoteEndOfConcMarkClosure(G1CollectedHeap* g1,
-                           int worker_num)
+                           int worker_num,
+                           FreeRegionList* local_cleanup_list,
+                           HumongousRegionSet* humongous_proxy_set,
+                           HRRSCleanupTask* hrrs_cleanup_task)
   : _g1(g1), _worker_num(worker_num),
     _max_live_bytes(0), _regions_claimed(0),
     _freed_bytes(0),
     _claimed_region_time(0.0), _max_region_time(0.0),
-    _local_cleanup_list("Local Cleanup List"),
-    _humongous_proxy_set("Local Cleanup Humongous Proxy Set") { }
+    _local_cleanup_list(local_cleanup_list),
+    _humongous_proxy_set(humongous_proxy_set),
+    _hrrs_cleanup_task(hrrs_cleanup_task) { }
 
 bool G1NoteEndOfConcMarkClosure::doHeapRegion(HeapRegion *hr) {
   // We use a claim value of zero here because all regions
@@ -1619,11 +1628,12 @@
     _regions_claimed++;
     hr->note_end_of_marking();
     _max_live_bytes += hr->max_live_bytes();
-    _g1->free_region_if_totally_empty(hr,
-                                      &_freed_bytes,
-                                      &_local_cleanup_list,
-                                      &_humongous_proxy_set,
-                                      true /* par */);
+    _g1->free_region_if_empty(hr,
+                              &_freed_bytes,
+                              _local_cleanup_list,
+                              _humongous_proxy_set,
+                              _hrrs_cleanup_task,
+                              true /* par */);
     double region_time = (os::elapsedTime() - start);
     _claimed_region_time += region_time;
     if (region_time > _max_region_time) _max_region_time = region_time;
@@ -1659,6 +1669,8 @@
 
   double start = os::elapsedTime();
 
+  HeapRegionRemSet::reset_for_cleanup_tasks();
+
   // Do counting once more with the world stopped for good measure.
   G1ParFinalCountTask g1_par_count_task(g1h, nextMarkBitMap(),
                                         &_region_bm, &_card_bm);