1 /*
2 * Copyright (c) 2001, 2013, 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.
18 *
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
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc_implementation/g1/g1BiasedArray.hpp"
27 #include "gc_implementation/g1/g1RegionToSpaceMapper.hpp"
28 #include "runtime/virtualspace.hpp"
29 #include "services/memTracker.hpp"
30
31 G1RegionToSpaceMapper::G1RegionToSpaceMapper(ReservedSpace rs,
32 size_t commit_granularity,
33 size_t region_granularity,
34 MemoryType type) :
35 _storage(),
36 _commit_granularity(commit_granularity),
37 _region_granularity(region_granularity),
38 _listener(NULL),
39 _commit_map() {
40 guarantee(is_power_of_2(commit_granularity), "must be");
41 guarantee(is_power_of_2(region_granularity), "must be");
42 _storage.initialize_with_granularity(rs, commit_granularity);
43
44 MemTracker::record_virtual_memory_type((address)rs.base(), type);
45 }
46
47 // G1RegionToSpaceMapper implementation where the region granularity is larger than
48 // or the same as the commit granularity.
49 // Basically, the space corresponding to one region region spans several OS pages.
50 class G1RegionsLargerThanCommitSizeMapper : public G1RegionToSpaceMapper {
51 private:
52 size_t _pages_per_region;
53
54 public:
55 G1RegionsLargerThanCommitSizeMapper(ReservedSpace rs, size_t os_commit_granularity,
56 size_t alloc_granularity, size_t commit_factor, MemoryType type) :
57 G1RegionToSpaceMapper(rs, os_commit_granularity, alloc_granularity, type),
58 _pages_per_region(alloc_granularity / (os_commit_granularity * commit_factor)) {
59
60 guarantee(alloc_granularity >= os_commit_granularity, "allocation granularity smaller than commit granularity");
61 _commit_map.resize(rs.size() * commit_factor / alloc_granularity, /* in_resource_area */ false);
62 }
63
64 virtual void commit_regions(uintptr_t start_idx, size_t num_regions) {
65 _storage.commit(start_idx * _pages_per_region, num_regions * _pages_per_region);
66 _commit_map.set_range(start_idx, start_idx + num_regions);
67 fire_on_commit(start_idx, num_regions);
68 }
69
70 virtual void uncommit_regions(uintptr_t start_idx, size_t num_regions) {
71 _storage.uncommit(start_idx * _pages_per_region, num_regions * _pages_per_region);
72 _commit_map.clear_range(start_idx, start_idx + num_regions);
73 }
74 };
75
76 // G1RegionToSpaceMapper implementation where the region granularity is smaller
77 // than the commit granularity.
78 // Basically, the contents of one OS page span several regions.
79 class G1RegionsSmallerThanCommitSizeMapper : public G1RegionToSpaceMapper {
80 private:
81 class CommitRefcountArray : public G1BiasedMappedArray<uint> {
82 protected:
83 virtual uint default_value() const { return 0; }
84 };
85
86 size_t _regions_per_page;
87
88 CommitRefcountArray _refcounts;
89
90 uintptr_t region_idx_to_page_idx(uint region) const {
91 return region / _regions_per_page;
92 }
93
94 public:
95 G1RegionsSmallerThanCommitSizeMapper(ReservedSpace rs,
96 size_t os_commit_granularity,
97 size_t alloc_granularity,
98 size_t commit_factor,
99 MemoryType type) :
100 G1RegionToSpaceMapper(rs, os_commit_granularity, alloc_granularity, type),
101 _regions_per_page((os_commit_granularity * commit_factor) / alloc_granularity), _refcounts() {
102
103 guarantee((os_commit_granularity * commit_factor) >= alloc_granularity, "allocation granularity smaller than commit granularity");
104 _refcounts.initialize((HeapWord*)rs.base(), (HeapWord*)(rs.base() + rs.size()), os_commit_granularity);
105 _commit_map.resize(rs.size() * commit_factor / alloc_granularity, /* in_resource_area */ false);
106 }
107
108 virtual void commit_regions(uintptr_t start_idx, size_t num_regions) {
109 for (uintptr_t i = start_idx; i < start_idx + num_regions; i++) {
110 assert(!_commit_map.at(i), err_msg("Trying to commit storage at region "INTPTR_FORMAT" that is already committed", i));
111 uintptr_t idx = region_idx_to_page_idx(i);
112 uint old_refcount = _refcounts.get_by_index(idx);
113 if (old_refcount == 0) {
114 _storage.commit(idx, 1);
115 }
116 _refcounts.set_by_index(idx, old_refcount + 1);
117 _commit_map.set_bit(i);
118 fire_on_commit(i, 1);
119 }
120 }
121
122 virtual void uncommit_regions(uintptr_t start_idx, size_t num_regions) {
123 for (uintptr_t i = start_idx; i < start_idx + num_regions; i++) {
124 assert(_commit_map.at(i), err_msg("Trying to uncommit storage at region "INTPTR_FORMAT" that is not committed", i));
125 uintptr_t idx = region_idx_to_page_idx(i);
126 uint old_refcount = _refcounts.get_by_index(idx);
127 assert(old_refcount > 0, "must be");
128 if (old_refcount == 1) {
129 _storage.uncommit(idx, 1);
130 }
131 _refcounts.set_by_index(idx, old_refcount - 1);
132 _commit_map.clear_bit(i);
133 }
134 }
135 };
136
137 void G1RegionToSpaceMapper::fire_on_commit(uint start_idx, size_t num_regions) {
138 if (_listener != NULL) {
139 _listener->on_commit(start_idx, num_regions);
140 }
141 }
142
143 G1RegionToSpaceMapper* G1RegionToSpaceMapper::create_mapper(ReservedSpace rs,
144 size_t os_commit_granularity, size_t region_granularity, size_t commit_factor, MemoryType type) {
145
146 if (region_granularity >= (os_commit_granularity * commit_factor)) {
147 return new G1RegionsLargerThanCommitSizeMapper(rs, os_commit_granularity, region_granularity, commit_factor, type);
148 } else {
149 return new G1RegionsSmallerThanCommitSizeMapper(rs, os_commit_granularity, region_granularity, commit_factor, type);
150 }
151 }