8343782: G1: Use one G1CardSet instance for multiple old gen regions

Reviewed-by: ayang, tschatzl

Author: Ivan Walulya

src/hotspot/share/gc/g1/g1CardSet.cpp

@@ -779,6 +779,15 @@ G1AddCardResult G1CardSet::add_card(uintptr_t card) {
   uint card_within_region;
   split_card(card, card_region, card_within_region);
 
+#ifdef ASSERT
+  {
+    uint region_idx = card_region >> config()->log2_card_regions_per_heap_region();
+    G1HeapRegion* r = G1CollectedHeap::heap()->region_at(region_idx);
+    assert(!r->rem_set()->is_added_to_cset_group() ||
+           r->rem_set()->cset_group()->card_set() != this, "Should not be sharing a cardset");
+  }
+#endif
+
   return add_card(card_region, card_within_region, true /* increment_total */);
 }
 

src/hotspot/share/gc/g1/g1CollectedHeap.cpp

@@ -1159,8 +1159,7 @@ G1CollectedHeap::G1CollectedHeap() :
   _rem_set(nullptr),
   _card_set_config(),
   _card_set_freelist_pool(G1CardSetConfiguration::num_mem_object_types()),
-  _young_regions_cardset_mm(card_set_config(), card_set_freelist_pool()),
-  _young_regions_cardset(card_set_config(), &_young_regions_cardset_mm),
+  _young_regions_cset_group(card_set_config(), &_card_set_freelist_pool, 1u /* group_id */),
   _cm(nullptr),
   _cm_thread(nullptr),
   _cr(nullptr),
@@ -2716,7 +2715,7 @@ bool G1CollectedHeap::is_old_gc_alloc_region(G1HeapRegion* hr) {
 void G1CollectedHeap::set_region_short_lived_locked(G1HeapRegion* hr) {
   _eden.add(hr);
   _policy->set_region_eden(hr);
-  hr->install_group_cardset(young_regions_cardset());
+  young_regions_cset_group()->add(hr);
 }
 
 #ifdef ASSERT
@@ -2927,7 +2926,7 @@ G1HeapRegion* G1CollectedHeap::new_gc_alloc_region(size_t word_size, G1HeapRegio
       _survivor.add(new_alloc_region);
       register_new_survivor_region_with_region_attr(new_alloc_region);
       // Install the group cardset.
-      new_alloc_region->install_group_cardset(young_regions_cardset());
+      young_regions_cset_group()->add(new_alloc_region);
     } else {
       new_alloc_region->set_old();
     }
@@ -3070,6 +3069,8 @@ void G1CollectedHeap::finish_codecache_marking_cycle() {
   CodeCache::arm_all_nmethods();
 }
 
-void G1CollectedHeap::prepare_group_cardsets_for_scan () {
-  _young_regions_cardset.reset_table_scanner_for_groups();
+void G1CollectedHeap::prepare_group_cardsets_for_scan() {
+  young_regions_cardset()->reset_table_scanner_for_groups();
+
+  collection_set()->prepare_groups_for_scan();
 }

src/hotspot/share/gc/g1/g1CollectedHeap.hpp

@@ -781,15 +781,15 @@ class G1CollectedHeap : public CollectedHeap {
   G1MonotonicArenaFreePool _card_set_freelist_pool;
 
   // Group cardsets
-  G1CardSetMemoryManager _young_regions_cardset_mm;
-  G1CardSet _young_regions_cardset;
+  G1CSetCandidateGroup _young_regions_cset_group;
 
 public:
   G1CardSetConfiguration* card_set_config() { return &_card_set_config; }
 
-  G1CardSet* young_regions_cardset() { return &_young_regions_cardset; };
+  G1CSetCandidateGroup* young_regions_cset_group() { return &_young_regions_cset_group; }
+  G1CardSet* young_regions_cardset() { return _young_regions_cset_group.card_set(); };
 
-  G1CardSetMemoryManager* young_regions_card_set_mm() { return &_young_regions_cardset_mm; }
+  G1MonotonicArenaMemoryStats young_regions_card_set_memory_stats() { return _young_regions_cset_group.card_set_memory_stats(); }
 
   void prepare_group_cardsets_for_scan();
 

src/hotspot/share/gc/g1/g1CollectedHeap.inline.hpp

@@ -225,7 +225,6 @@ void G1CollectedHeap::register_region_with_region_attr(G1HeapRegion* r) {
 }
 
 void G1CollectedHeap::register_old_region_with_region_attr(G1HeapRegion* r) {
-  assert(!r->has_pinned_objects(), "must be");
   assert(r->rem_set()->is_complete(), "must be");
   _region_attr.set_in_old(r->hrm_index(), true);
   _rem_set->exclude_region_from_scan(r->hrm_index());