g1RegionToSpaceMapper.cpp revision 8413:92457dfb91bd 
1/*
2 * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
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23 */
24
25#include "precompiled.hpp"
26#include "gc/g1/g1BiasedArray.hpp"
27#include "gc/g1/g1RegionToSpaceMapper.hpp"
28#include "memory/allocation.inline.hpp"
29#include "memory/virtualspace.hpp"
30#include "services/memTracker.hpp"
31#include "utilities/bitMap.inline.hpp"
32
33G1RegionToSpaceMapper::G1RegionToSpaceMapper(ReservedSpace rs,
34                                             size_t used_size,
35                                             size_t page_size,
36                                             size_t region_granularity,
37                                             MemoryType type) :
38  _storage(rs, used_size, page_size),
39  _region_granularity(region_granularity),
40  _listener(NULL),
41  _commit_map() {
42  guarantee(is_power_of_2(page_size), "must be");
43  guarantee(is_power_of_2(region_granularity), "must be");
44
45  MemTracker::record_virtual_memory_type((address)rs.base(), type);
46}
47
48// G1RegionToSpaceMapper implementation where the region granularity is larger than
49// or the same as the commit granularity.
50// Basically, the space corresponding to one region region spans several OS pages.
51class G1RegionsLargerThanCommitSizeMapper : public G1RegionToSpaceMapper {
52 private:
53  size_t _pages_per_region;
54
55 public:
56  G1RegionsLargerThanCommitSizeMapper(ReservedSpace rs,
57                                      size_t actual_size,
58                                      size_t page_size,
59                                      size_t alloc_granularity,
60                                      size_t commit_factor,
61                                      MemoryType type) :
62    G1RegionToSpaceMapper(rs, actual_size, page_size, alloc_granularity, type),
63    _pages_per_region(alloc_granularity / (page_size * commit_factor)) {
64
65    guarantee(alloc_granularity >= page_size, "allocation granularity smaller than commit granularity");
66    _commit_map.resize(rs.size() * commit_factor / alloc_granularity, /* in_resource_area */ false);
67  }
68
69  virtual void commit_regions(uint start_idx, size_t num_regions) {
70    bool zero_filled = _storage.commit((size_t)start_idx * _pages_per_region, num_regions * _pages_per_region);
71    _commit_map.set_range(start_idx, start_idx + num_regions);
72    fire_on_commit(start_idx, num_regions, zero_filled);
73  }
74
75  virtual void uncommit_regions(uint start_idx, size_t num_regions) {
76    _storage.uncommit((size_t)start_idx * _pages_per_region, num_regions * _pages_per_region);
77    _commit_map.clear_range(start_idx, start_idx + num_regions);
78  }
79};
80
81// G1RegionToSpaceMapper implementation where the region granularity is smaller
82// than the commit granularity.
83// Basically, the contents of one OS page span several regions.
84class G1RegionsSmallerThanCommitSizeMapper : public G1RegionToSpaceMapper {
85 private:
86  class CommitRefcountArray : public G1BiasedMappedArray<uint> {
87   protected:
88     virtual uint default_value() const { return 0; }
89  };
90
91  size_t _regions_per_page;
92
93  CommitRefcountArray _refcounts;
94
95  uintptr_t region_idx_to_page_idx(uint region) const {
96    return region / _regions_per_page;
97  }
98
99 public:
100  G1RegionsSmallerThanCommitSizeMapper(ReservedSpace rs,
101                                       size_t actual_size,
102                                       size_t page_size,
103                                       size_t alloc_granularity,
104                                       size_t commit_factor,
105                                       MemoryType type) :
106    G1RegionToSpaceMapper(rs, actual_size, page_size, alloc_granularity, type),
107    _regions_per_page((page_size * commit_factor) / alloc_granularity), _refcounts() {
108
109    guarantee((page_size * commit_factor) >= alloc_granularity, "allocation granularity smaller than commit granularity");
110    _refcounts.initialize((HeapWord*)rs.base(), (HeapWord*)(rs.base() + align_size_up(rs.size(), page_size)), page_size);
111    _commit_map.resize(rs.size() * commit_factor / alloc_granularity, /* in_resource_area */ false);
112  }
113
114  virtual void commit_regions(uint start_idx, size_t num_regions) {
115    for (uint i = start_idx; i < start_idx + num_regions; i++) {
116      assert(!_commit_map.at(i), err_msg("Trying to commit storage at region %u that is already committed", i));
117      size_t idx = region_idx_to_page_idx(i);
118      uint old_refcount = _refcounts.get_by_index(idx);
119      bool zero_filled = false;
120      if (old_refcount == 0) {
121        zero_filled = _storage.commit(idx, 1);
122      }
123      _refcounts.set_by_index(idx, old_refcount + 1);
124      _commit_map.set_bit(i);
125      fire_on_commit(i, 1, zero_filled);
126    }
127  }
128
129  virtual void uncommit_regions(uint start_idx, size_t num_regions) {
130    for (uint i = start_idx; i < start_idx + num_regions; i++) {
131      assert(_commit_map.at(i), err_msg("Trying to uncommit storage at region %u that is not committed", i));
132      size_t idx = region_idx_to_page_idx(i);
133      uint old_refcount = _refcounts.get_by_index(idx);
134      assert(old_refcount > 0, "must be");
135      if (old_refcount == 1) {
136        _storage.uncommit(idx, 1);
137      }
138      _refcounts.set_by_index(idx, old_refcount - 1);
139      _commit_map.clear_bit(i);
140    }
141  }
142};
143
144void G1RegionToSpaceMapper::fire_on_commit(uint start_idx, size_t num_regions, bool zero_filled) {
145  if (_listener != NULL) {
146    _listener->on_commit(start_idx, num_regions, zero_filled);
147  }
148}
149
150G1RegionToSpaceMapper* G1RegionToSpaceMapper::create_mapper(ReservedSpace rs,
151                                                            size_t actual_size,
152                                                            size_t page_size,
153                                                            size_t region_granularity,
154                                                            size_t commit_factor,
155                                                            MemoryType type) {
156
157  if (region_granularity >= (page_size * commit_factor)) {
158    return new G1RegionsLargerThanCommitSizeMapper(rs, actual_size, page_size, region_granularity, commit_factor, type);
159  } else {
160    return new G1RegionsSmallerThanCommitSizeMapper(rs, actual_size, page_size, region_granularity, commit_factor, type);
161  }
162}
163