src/share/vm/gc_implementation/g1/heapRegion.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:

*** 1,7 ****
  /*
!  * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
--- 1,7 ----
  /*
!  * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
*** 203,213 ****
    // treat all objects as being inside the unmarked area.
    zero_marked_bytes();
    init_top_at_mark_start();
  }
  
! void HeapRegion::hr_clear(bool par, bool clear_space) {
    assert(_humongous_type == NotHumongous,
           "we should have already filtered out humongous regions");
    assert(_humongous_start_region == NULL,
           "we should have already filtered out humongous regions");
    assert(_end == _orig_end,
--- 203,213 ----
    // treat all objects as being inside the unmarked area.
    zero_marked_bytes();
    init_top_at_mark_start();
  }
  
! void HeapRegion::hr_clear(bool par, bool clear_space, bool locked) {
    assert(_humongous_type == NotHumongous,
           "we should have already filtered out humongous regions");
    assert(_humongous_start_region == NULL,
           "we should have already filtered out humongous regions");
    assert(_end == _orig_end,
*** 221,231 ****
--- 221,235 ----
    reset_pre_dummy_top();
  
    if (!par) {
      // If this is parallel, this will be done later.
      HeapRegionRemSet* hrrs = rem_set();
+     if (locked) {
+       hrrs->clear_locked();
+     } else {
        hrrs->clear();
+     }
      _claimed = InitialClaimValue;
    }
    zero_marked_bytes();
  
    _offsets.resize(HeapRegion::GrainWords);