src/share/vm/gc_implementation/g1/g1RegionToSpaceMapper.hpp

rev 7746 : 8058354: SPECjvm2008-Derby -2.7% performance regression on Solaris-X64 starting with 9-b29
Summary: Allow partial use of large pages for auxiliary data structures in G1.
Reviewed-by:

*** 1,7 ****
  /*
!  * Copyright (c) 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.
--- 1,7 ----
  /*
!  * Copyright (c) 2014, 2015 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.
*** 49,59 ****
    size_t _commit_granularity;
    size_t _region_granularity;
    // Mapping management
    BitMap _commit_map;
  
!   G1RegionToSpaceMapper(ReservedSpace rs, size_t commit_granularity, size_t region_granularity, MemoryType type);
  
    void fire_on_commit(uint start_idx, size_t num_regions, bool zero_filled);
   public:
    MemRegion reserved() { return _storage.reserved(); }
  
--- 49,59 ----
    size_t _commit_granularity;
    size_t _region_granularity;
    // Mapping management
    BitMap _commit_map;
  
!   G1RegionToSpaceMapper(ReservedSpace rs, size_t actual_size, size_t commit_granularity, size_t region_granularity, MemoryType type);
  
    void fire_on_commit(uint start_idx, size_t num_regions, bool zero_filled);
   public:
    MemRegion reserved() { return _storage.reserved(); }
  
*** 69,83 ****
  
    virtual void commit_regions(uintptr_t start_idx, size_t num_regions = 1) = 0;
    virtual void uncommit_regions(uintptr_t start_idx, size_t num_regions = 1) = 0;
  
    // Creates an appropriate G1RegionToSpaceMapper for the given parameters.
    // The byte_translation_factor defines how many bytes in a region correspond to
    // a single byte in the data structure this mapper is for.
    // Eg. in the card table, this value corresponds to the size a single card
!   // table entry corresponds to.
    static G1RegionToSpaceMapper* create_mapper(ReservedSpace rs,
                                                size_t os_commit_granularity,
                                                size_t region_granularity,
                                                size_t byte_translation_factor,
                                                MemoryType type);
  };
--- 69,87 ----
  
    virtual void commit_regions(uintptr_t start_idx, size_t num_regions = 1) = 0;
    virtual void uncommit_regions(uintptr_t start_idx, size_t num_regions = 1) = 0;
  
    // Creates an appropriate G1RegionToSpaceMapper for the given parameters.
+   // The actual space to be used within the given reservation is given by actual_size.
+   // This is because some OSes need to round up the reservation size to guarantee
+   // alignment of os_commit_granularity.
    // The byte_translation_factor defines how many bytes in a region correspond to
    // a single byte in the data structure this mapper is for.
    // Eg. in the card table, this value corresponds to the size a single card
!   // table entry corresponds to in the heap.
    static G1RegionToSpaceMapper* create_mapper(ReservedSpace rs,
+                                               size_t actual_size,
                                                size_t os_commit_granularity,
                                                size_t region_granularity,
                                                size_t byte_translation_factor,
                                                MemoryType type);
  };