1 /*
2 * Copyright (c) 2001, 2017, 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 "logging/log.hpp"
26 #include "precompiled.hpp"
27 #include "gc/g1/g1BiasedArray.hpp"
28 #include "gc/g1/g1RegionToSpaceMapper.hpp"
29 #include "memory/allocation.inline.hpp"
30 #include "memory/virtualspace.hpp"
31 #include "runtime/java.hpp"
32 #include "services/memTracker.hpp"
33 #include "utilities/align.hpp"
34 #include "utilities/bitMap.inline.hpp"
35 #include "utilities/formatBuffer.hpp"
36
37 G1RegionToSpaceMapper::G1RegionToSpaceMapper(ReservedSpace rs,
38 size_t used_size,
39 size_t page_size,
40 size_t region_granularity,
41 size_t commit_factor,
42 MemoryType type) :
43 _listener(NULL),
44 _storage(rs, used_size, page_size),
45 _region_granularity(region_granularity),
46 _commit_map(rs.size() * commit_factor / region_granularity, mtGC) {
47 guarantee(is_power_of_2(page_size), "must be");
48 guarantee(is_power_of_2(region_granularity), "must be");
49
50 MemTracker::record_virtual_memory_type((address)rs.base(), type);
51 }
52
53 // G1RegionToSpaceMapper implementation where the region granularity is larger than
54 // or the same as the commit granularity.
55 // Basically, the space corresponding to one region region spans several OS pages.
56 class G1RegionsLargerThanCommitSizeMapper : public G1RegionToSpaceMapper {
57 private:
58 size_t _pages_per_region;
59
60 public:
61 G1RegionsLargerThanCommitSizeMapper(ReservedSpace rs,
62 size_t actual_size,
63 size_t page_size,
64 size_t alloc_granularity,
65 size_t commit_factor,
66 MemoryType type) :
67 G1RegionToSpaceMapper(rs, actual_size, page_size, alloc_granularity, commit_factor, type),
68 _pages_per_region(alloc_granularity / (page_size * commit_factor)) {
69
70 guarantee(alloc_granularity >= page_size, "allocation granularity smaller than commit granularity");
71 }
72
73 virtual void commit_regions(uint start_idx, size_t num_regions, WorkGang* pretouch_gang) {
74 size_t const start_page = (size_t)start_idx * _pages_per_region;
75 bool zero_filled = _storage.commit(start_page, num_regions * _pages_per_region);
76 if (AlwaysPreTouch) {
77 _storage.pretouch(start_page, num_regions * _pages_per_region, pretouch_gang);
78 }
79 _commit_map.set_range(start_idx, start_idx + num_regions);
80 fire_on_commit(start_idx, num_regions, zero_filled);
81 }
82
83 virtual void uncommit_regions(uint start_idx, size_t num_regions) {
84 _storage.uncommit((size_t)start_idx * _pages_per_region, num_regions * _pages_per_region);
85 _commit_map.clear_range(start_idx, start_idx + num_regions);
86 }
87 };
88
89 // G1RegionToSpaceMapper implementation where the region granularity is smaller
90 // than the commit granularity.
91 // Basically, the contents of one OS page span several regions.
92 class G1RegionsSmallerThanCommitSizeMapper : public G1RegionToSpaceMapper {
93 private:
94 class CommitRefcountArray : public G1BiasedMappedArray<uint> {
95 protected:
96 virtual uint default_value() const { return 0; }
97 };
98
99 size_t _regions_per_page;
100
101 CommitRefcountArray _refcounts;
102
103 uintptr_t region_idx_to_page_idx(uint region) const {
104 return region / _regions_per_page;
105 }
106
107 public:
108 G1RegionsSmallerThanCommitSizeMapper(ReservedSpace rs,
109 size_t actual_size,
110 size_t page_size,
111 size_t alloc_granularity,
112 size_t commit_factor,
113 MemoryType type) :
114 G1RegionToSpaceMapper(rs, actual_size, page_size, alloc_granularity, commit_factor, type),
115 _regions_per_page((page_size * commit_factor) / alloc_granularity), _refcounts() {
116
117 guarantee((page_size * commit_factor) >= alloc_granularity, "allocation granularity smaller than commit granularity");
118 _refcounts.initialize((HeapWord*)rs.base(), (HeapWord*)(rs.base() + align_up(rs.size(), page_size)), page_size);
119 }
120
121 virtual void commit_regions(uint start_idx, size_t num_regions, WorkGang* pretouch_gang) {
122 size_t const NoPage = ~(size_t)0;
123
124 size_t first_committed = NoPage;
125 size_t num_committed = 0;
126
127 bool all_zero_filled = true;
128
129 for (uint i = start_idx; i < start_idx + num_regions; i++) {
130 assert(!_commit_map.at(i), "Trying to commit storage at region %u that is already committed", i);
131 size_t idx = region_idx_to_page_idx(i);
132 uint old_refcount = _refcounts.get_by_index(idx);
133
134 bool zero_filled = false;
135 if (old_refcount == 0) {
136 if (first_committed == NoPage) {
137 first_committed = idx;
138 num_committed = 1;
139 } else {
140 num_committed++;
141 }
142 zero_filled = _storage.commit(idx, 1);
143 }
144 all_zero_filled &= zero_filled;
145
146 _refcounts.set_by_index(idx, old_refcount + 1);
147 _commit_map.set_bit(i);
148 }
149 if (AlwaysPreTouch && num_committed > 0) {
150 _storage.pretouch(first_committed, num_committed, pretouch_gang);
151 }
152 fire_on_commit(start_idx, num_regions, all_zero_filled);
153 }
154
155 virtual void uncommit_regions(uint start_idx, size_t num_regions) {
156 for (uint i = start_idx; i < start_idx + num_regions; i++) {
157 assert(_commit_map.at(i), "Trying to uncommit storage at region %u that is not committed", i);
158 size_t idx = region_idx_to_page_idx(i);
159 uint old_refcount = _refcounts.get_by_index(idx);
160 assert(old_refcount > 0, "must be");
161 if (old_refcount == 1) {
162 _storage.uncommit(idx, 1);
163 }
164 _refcounts.set_by_index(idx, old_refcount - 1);
165 _commit_map.clear_bit(i);
166 }
167 }
168 };
169
170 void G1RegionToSpaceMapper::fire_on_commit(uint start_idx, size_t num_regions, bool zero_filled) {
171 if (_listener != NULL) {
172 _listener->on_commit(start_idx, num_regions, zero_filled);
173 }
174 }
175
176 static bool map_nvdimm_space(ReservedSpace rs) {
177 assert(AllocateOldGenAt != NULL, "");
178 int _backing_fd = os::create_file_for_heap(AllocateOldGenAt);
179 if (_backing_fd == -1) {
180 return false;
181 log_error(gc, init)("Could not create file for Old generation at location %s", AllocateOldGenAt);
182 }
183 // commit this memory in nv-dimm
184 char* ret = os::attempt_reserve_memory_at(rs.size(), rs.base(), _backing_fd);
185
186 if (ret != rs.base()) {
187 if (ret != NULL) {
188 os::unmap_memory(rs.base(), rs.size());
189 }
190 log_error(gc, init)("Error in mapping Old Gen to given AllocateOldGenAt = %s", AllocateOldGenAt);
191 return false;
192 }
193 return true;
194 }
195
196 G1RegionToHeteroSpaceMapper::G1RegionToHeteroSpaceMapper(ReservedSpace rs,
197 size_t actual_size,
198 size_t page_size,
199 size_t alloc_granularity,
200 size_t commit_factor,
201 MemoryType type) :
202 G1RegionToSpaceMapper(rs, actual_size, page_size, alloc_granularity, commit_factor, type),
203 _num_committed_dram(0), _num_committed_nvdimm(0), _success(false) {
204 assert(actual_size == 2 * MaxHeapSize, "For 2-way heterogenuous heap, reserved space is two times MaxHeapSize");
205
206 // Since we need to re-map the reserved space - 'Xmx' to nv-dimm and 'Xmx' to dram, we need to release the reserved memory first.
207 // Because on some OSes (e.g. Windows) you cannot do a file mapping on memory reserved with regular mapping.
208 os::release_memory(rs.base(), rs.size());
209 // First half of size Xmx is for nv-dimm.
210 ReservedSpace rs_nvdimm = rs.first_part(MaxHeapSize);
211 assert(rs_nvdimm.base() == rs.base(), "We should get the same base address");
212
213 // Second half of reserved memory is mapped to dram.
214 ReservedSpace rs_dram = rs.last_part(MaxHeapSize);
215
216 assert(rs_dram.size() == rs_nvdimm.size() && rs_nvdimm.size() == MaxHeapSize, "They all should be same");
217
218 // Reserve dram memory
219 char* base = os::attempt_reserve_memory_at(rs_dram.size(), rs_dram.base());
220 if (base != rs_dram.base()) {
221 if (base != NULL) {
222 os::release_memory(base, rs_dram.size());
223 }
224 log_error(gc, init)("Error in re-mapping memory on dram during G1 heterogenous memory initialization");
225 return;
226 }
227
228 // We reserve and commit this entire space to NV-DIMM.
229 if (!map_nvdimm_space(rs_nvdimm)) {
230 log_error(gc, init)("Error in re-mapping memory to nv-dimm during G1 heterogenous memory initialization");
231 return;
232 }
233
234 if (alloc_granularity >= (page_size * commit_factor)) {
235 _dram_mapper = new G1RegionsLargerThanCommitSizeMapper(rs_dram, rs_dram.size(), page_size, alloc_granularity, commit_factor, type);
236 }
237 else {
238 _dram_mapper = new G1RegionsSmallerThanCommitSizeMapper(rs_dram, rs_dram.size(), page_size, alloc_granularity, commit_factor, type);
239 }
240
241 _start_index_of_nvdimm = 0;
242 _start_index_of_dram = (uint)(rs_nvdimm.size() / alloc_granularity);
243 _success = true;
244 }
245
246 void G1RegionToHeteroSpaceMapper::commit_regions(uint start_idx, size_t num_regions, WorkGang* pretouch_gang) {
247 uint end_idx = (start_idx + (uint)num_regions - 1);
248
249 uint num_dram = end_idx >= _start_index_of_dram ? MIN2((end_idx - _start_index_of_dram + 1), (uint)num_regions) : 0;
250 uint num_nvdimm = (uint)num_regions - num_dram;
251
252 if (num_nvdimm > 0) {
253 // We do not need to commit nv-dimm regions, since they are committed in the beginning.
254 _num_committed_nvdimm += num_nvdimm;
255 }
256 if (num_dram > 0) {
257 _dram_mapper->commit_regions(start_idx > _start_index_of_dram ? (start_idx - _start_index_of_dram) : 0, num_dram, pretouch_gang);
258 _num_committed_dram += num_dram;
259 }
260 }
261
262 void G1RegionToHeteroSpaceMapper::uncommit_regions(uint start_idx, size_t num_regions) {
263 uint end_idx = (start_idx + (uint)num_regions - 1);
264 uint num_dram = end_idx >= _start_index_of_dram ? MIN2((end_idx - _start_index_of_dram + 1), (uint)num_regions) : 0;
265 uint num_nvdimm = (uint)num_regions - num_dram;
266
267 if (num_nvdimm > 0) {
268 // We do not uncommit memory for nv-dimm regions.
269 _num_committed_nvdimm -= num_nvdimm;
270 }
271
272 if (num_dram > 0) {
273 _dram_mapper->uncommit_regions(start_idx > _start_index_of_dram ? (start_idx - _start_index_of_dram) : 0, num_dram);
274 _num_committed_dram -= num_dram;
275 }
276 }
277
278 uint G1RegionToHeteroSpaceMapper::num_committed_dram() const {
279 return _num_committed_dram;
280 }
281
282 uint G1RegionToHeteroSpaceMapper::num_committed_nvdimm() const {
283 return _num_committed_nvdimm;
284 }
285
286 G1RegionToSpaceMapper* G1RegionToSpaceMapper::create_heap_mapper(ReservedSpace rs,
287 size_t actual_size,
288 size_t page_size,
289 size_t region_granularity,
290 size_t commit_factor,
291 MemoryType type) {
292 if (AllocateOldGenAt != NULL) {
293 G1RegionToHeteroSpaceMapper* mapper = new G1RegionToHeteroSpaceMapper(rs, actual_size, page_size, region_granularity, commit_factor, type);
294 if (!mapper->success()) {
295 delete mapper;
296 return NULL;
297 }
298 return (G1RegionToSpaceMapper*)mapper;
299 } else {
300 return create_mapper(rs, actual_size, page_size, region_granularity, commit_factor, type);
301 }
302 }
303
304 G1RegionToSpaceMapper* G1RegionToSpaceMapper::create_mapper(ReservedSpace rs,
305 size_t actual_size,
306 size_t page_size,
307 size_t region_granularity,
308 size_t commit_factor,
309 MemoryType type) {
310 if (region_granularity >= (page_size * commit_factor)) {
311 return new G1RegionsLargerThanCommitSizeMapper(rs, actual_size, page_size, region_granularity, commit_factor, type);
312 } else {
313 return new G1RegionsSmallerThanCommitSizeMapper(rs, actual_size, page_size, region_granularity, commit_factor, type);
314 }
315 }