src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp

rev 5920 : 8035406: Improve data structure for Code Cache remembered sets
Summary: Change the code cache remembered sets data structure from a GrowableArray to a chunked list of nmethods. This makes the data structure more amenable to parallelization, and decreases freeing time.
Reviewed-by:
rev 5921 : 8027295: Free CSet takes ~50% of young pause time
Summary: Improve fast card cache iteration and avoid taking locks when freeing the collection set.
Reviewed-by:

*** 5964,5974 ****
  }
  
  void G1CollectedHeap::free_region(HeapRegion* hr,
                                    size_t* pre_used,
                                    FreeRegionList* free_list,
!                                   bool par) {
    assert(!hr->isHumongous(), "this is only for non-humongous regions");
    assert(!hr->is_empty(), "the region should not be empty");
    assert(free_list != NULL, "pre-condition");
  
    // Clear the card counts for this region.
--- 5964,5974 ----
  }
  
  void G1CollectedHeap::free_region(HeapRegion* hr,
                                    size_t* pre_used,
                                    FreeRegionList* free_list,
!                                   bool par, bool locked) {
    assert(!hr->isHumongous(), "this is only for non-humongous regions");
    assert(!hr->is_empty(), "the region should not be empty");
    assert(free_list != NULL, "pre-condition");
  
    // Clear the card counts for this region.
*** 5976,5986 ****
    // (since we don't refine cards in young regions).
    if (!hr->is_young()) {
      _cg1r->hot_card_cache()->reset_card_counts(hr);
    }
    *pre_used += hr->used();
!   hr->hr_clear(par, true /* clear_space */);
    free_list->add_as_head(hr);
  }
  
  void G1CollectedHeap::free_humongous_region(HeapRegion* hr,
                                       size_t* pre_used,
--- 5976,5986 ----
    // (since we don't refine cards in young regions).
    if (!hr->is_young()) {
      _cg1r->hot_card_cache()->reset_card_counts(hr);
    }
    *pre_used += hr->used();
!   hr->hr_clear(par, true /* clear_space */, locked);
    free_list->add_as_head(hr);
  }
  
  void G1CollectedHeap::free_humongous_region(HeapRegion* hr,
                                       size_t* pre_used,
*** 6198,6208 ****
          start_sec = os::elapsedTime();
          non_young = true;
        }
      }
  
!     rs_lengths += cur->rem_set()->occupied();
  
      HeapRegion* next = cur->next_in_collection_set();
      assert(cur->in_collection_set(), "bad CS");
      cur->set_next_in_collection_set(NULL);
      cur->set_in_collection_set(false);
--- 6198,6208 ----
          start_sec = os::elapsedTime();
          non_young = true;
        }
      }
  
!     rs_lengths += cur->rem_set()->occupied_locked();
  
      HeapRegion* next = cur->next_in_collection_set();
      assert(cur->in_collection_set(), "bad CS");
      cur->set_next_in_collection_set(NULL);
      cur->set_in_collection_set(false);
*** 6231,6241 ****
      if (!cur->evacuation_failed()) {
        MemRegion used_mr = cur->used_region();
  
        // And the region is empty.
        assert(!used_mr.is_empty(), "Should not have empty regions in a CS.");
!       free_region(cur, &pre_used, &local_free_list, false /* par */);
      } else {
        cur->uninstall_surv_rate_group();
        if (cur->is_young()) {
          cur->set_young_index_in_cset(-1);
        }
--- 6231,6241 ----
      if (!cur->evacuation_failed()) {
        MemRegion used_mr = cur->used_region();
  
        // And the region is empty.
        assert(!used_mr.is_empty(), "Should not have empty regions in a CS.");
!       free_region(cur, &pre_used, &local_free_list, false /* par */, true /* locked */);
      } else {
        cur->uninstall_surv_rate_group();
        if (cur->is_young()) {
          cur->set_young_index_in_cset(-1);
        }