1 /*
2 * Copyright (c) 2001, 2019, 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/g1/g1BiasedArray.hpp"
27 #include "gc/g1/g1MemoryNodeManager.hpp"
28 #include "gc/g1/g1RegionToSpaceMapper.hpp"
29 #include "logging/log.hpp"
30 #include "memory/allocation.inline.hpp"
31 #include "memory/virtualspace.hpp"
32 #include "runtime/java.hpp"
33 #include "runtime/os.inline.hpp"
34 #include "services/memTracker.hpp"
35 #include "utilities/align.hpp"
36 #include "utilities/bitMap.inline.hpp"
37 #include "utilities/formatBuffer.hpp"
38
39 G1RegionToSpaceMapper::G1RegionToSpaceMapper(ReservedSpace rs,
40 size_t used_size,
41 size_t page_size,
42 size_t region_granularity,
43 size_t commit_factor,
44 MemoryType type) :
45 _listener(NULL),
46 _storage(rs, used_size, page_size, type),
47 _region_granularity(region_granularity),
48 _commit_map(rs.size() * commit_factor / region_granularity, mtGC) {
49 guarantee(is_power_of_2(page_size), "must be");
50 guarantee(is_power_of_2(region_granularity), "must be");
51
52 MemTracker::record_virtual_memory_type((address)rs.base(), type);
53 }
54
55 // G1RegionToSpaceMapper implementation where the region granularity is larger than
56 // or the same as the commit granularity.
57 // Basically, the space corresponding to one region region spans several OS pages.
58 class G1RegionsLargerThanCommitSizeMapper : public G1RegionToSpaceMapper {
59 private:
60 size_t _pages_per_region;
61
62 public:
63 G1RegionsLargerThanCommitSizeMapper(ReservedSpace rs,
64 size_t actual_size,
65 size_t page_size,
66 size_t alloc_granularity,
67 size_t commit_factor,
68 MemoryType type) :
69 G1RegionToSpaceMapper(rs, actual_size, page_size, alloc_granularity, commit_factor, type),
70 _pages_per_region(alloc_granularity / (page_size * commit_factor)) {
71
72 guarantee(alloc_granularity >= page_size, "allocation granularity smaller than commit granularity");
73 }
74
75 virtual void commit_regions(uint start_idx, size_t num_regions, WorkGang* pretouch_gang) {
76 const size_t start_page = (size_t)start_idx * _pages_per_region;
77 const size_t size_in_pages = num_regions * _pages_per_region;
78 bool zero_filled = _storage.commit(start_page, size_in_pages);
79 if (AlwaysPreTouch) {
80 _storage.pretouch(start_page, size_in_pages, pretouch_gang);
81 }
82 _commit_map.set_range(start_idx, start_idx + num_regions);
83 fire_on_commit(start_idx, num_regions, zero_filled);
84 }
85
86 virtual void uncommit_regions(uint start_idx, size_t num_regions) {
87 _storage.uncommit((size_t)start_idx * _pages_per_region, num_regions * _pages_per_region);
88 _commit_map.clear_range(start_idx, start_idx + num_regions);
89 }
90 };
91
92 // G1RegionToSpaceMapper implementation where the region granularity is smaller
93 // than the commit granularity.
94 // Basically, the contents of one OS page span several regions.
95 class G1RegionsSmallerThanCommitSizeMapper : public G1RegionToSpaceMapper {
96 private:
97 class CommitRefcountArray : public G1BiasedMappedArray<uint> {
98 protected:
99 virtual uint default_value() const { return 0; }
100 };
101
102 size_t _regions_per_page;
103
104 CommitRefcountArray _refcounts;
105
106 uintptr_t region_idx_to_page_idx(uint region) const {
107 return region / _regions_per_page;
108 }
109
110 public:
111 G1RegionsSmallerThanCommitSizeMapper(ReservedSpace rs,
112 size_t actual_size,
113 size_t page_size,
114 size_t alloc_granularity,
115 size_t commit_factor,
116 MemoryType type) :
117 G1RegionToSpaceMapper(rs, actual_size, page_size, alloc_granularity, commit_factor, type),
118 _regions_per_page((page_size * commit_factor) / alloc_granularity), _refcounts() {
119
120 guarantee((page_size * commit_factor) >= alloc_granularity, "allocation granularity smaller than commit granularity");
121 _refcounts.initialize((HeapWord*)rs.base(), (HeapWord*)(rs.base() + align_up(rs.size(), page_size)), page_size);
122 }
123
124 virtual void commit_regions(uint start_idx, size_t num_regions, WorkGang* pretouch_gang) {
125 size_t const NoPage = ~(size_t)0;
126
127 size_t first_committed = NoPage;
128 size_t num_committed = 0;
129
130 bool all_zero_filled = true;
131
132 for (uint i = start_idx; i < start_idx + num_regions; i++) {
133 assert(!_commit_map.at(i), "Trying to commit storage at region %u that is already committed", i);
134 size_t idx = region_idx_to_page_idx(i);
135 uint old_refcount = _refcounts.get_by_index(idx);
136
137 bool zero_filled = false;
138 if (old_refcount == 0) {
139 if (first_committed == NoPage) {
140 first_committed = idx;
141 num_committed = 1;
142 } else {
143 num_committed++;
144 }
145 zero_filled = _storage.commit(idx, 1);
146 }
147 all_zero_filled &= zero_filled;
148
149 _refcounts.set_by_index(idx, old_refcount + 1);
150 _commit_map.set_bit(i);
151 }
152 if (AlwaysPreTouch && num_committed > 0) {
153 _storage.pretouch(first_committed, num_committed, pretouch_gang);
154 }
155 fire_on_commit(start_idx, num_regions, all_zero_filled);
156 }
157
158 virtual void uncommit_regions(uint start_idx, size_t num_regions) {
159 for (uint i = start_idx; i < start_idx + num_regions; i++) {
160 assert(_commit_map.at(i), "Trying to uncommit storage at region %u that is not committed", i);
161 size_t idx = region_idx_to_page_idx(i);
162 uint old_refcount = _refcounts.get_by_index(idx);
163 assert(old_refcount > 0, "must be");
164 if (old_refcount == 1) {
165 _storage.uncommit(idx, 1);
166 }
167 _refcounts.set_by_index(idx, old_refcount - 1);
168 _commit_map.clear_bit(i);
169 }
170 }
171 };
172
173 void G1RegionToSpaceMapper::fire_on_commit(uint start_idx, size_t num_regions, bool zero_filled) {
174 if (_listener != NULL) {
175 _listener->on_commit(start_idx, num_regions, zero_filled);
176 }
177 }
178
179 static bool map_nvdimm_space(ReservedSpace rs) {
180 assert(AllocateOldGenAt != NULL, "");
181 int _backing_fd = os::create_file_for_heap(AllocateOldGenAt);
182 if (_backing_fd == -1) {
183 log_error(gc, init)("Could not create file for Old generation at location %s", AllocateOldGenAt);
184 return false;
185 }
186 // commit this memory in nv-dimm
187 char* ret = os::attempt_reserve_memory_at(rs.size(), rs.base(), _backing_fd);
188
189 if (ret != rs.base()) {
190 if (ret != NULL) {
191 os::unmap_memory(rs.base(), rs.size());
192 }
193 log_error(gc, init)("Error in mapping Old Gen to given AllocateOldGenAt = %s", AllocateOldGenAt);
194 os::close(_backing_fd);
195 return false;
196 }
197
198 os::close(_backing_fd);
199 return true;
200 }
201
202 G1RegionToHeteroSpaceMapper::G1RegionToHeteroSpaceMapper(ReservedSpace rs,
203 size_t actual_size,
204 size_t page_size,
205 size_t alloc_granularity,
206 size_t commit_factor,
207 MemoryType type) :
208 G1RegionToSpaceMapper(rs, actual_size, page_size, alloc_granularity, commit_factor, type),
209 _rs(rs),
210 _dram_mapper(NULL),
211 _num_committed_dram(0),
212 _num_committed_nvdimm(0),
213 _start_index_of_dram(0),
214 _page_size(page_size),
215 _commit_factor(commit_factor),
216 _type(type) {
217 assert(actual_size == 2 * MaxHeapSize, "For 2-way heterogenuous heap, reserved space is two times MaxHeapSize");
218 }
219
220 bool G1RegionToHeteroSpaceMapper::initialize() {
221 // 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.
222 // Because on some OSes (e.g. Windows) you cannot do a file mapping on memory reserved with regular mapping.
223 os::release_memory(_rs.base(), _rs.size());
224 // First half of size Xmx is for nv-dimm.
225 ReservedSpace rs_nvdimm = _rs.first_part(MaxHeapSize);
226 assert(rs_nvdimm.base() == _rs.base(), "We should get the same base address");
227
228 // Second half of reserved memory is mapped to dram.
229 ReservedSpace rs_dram = _rs.last_part(MaxHeapSize);
230
231 assert(rs_dram.size() == rs_nvdimm.size() && rs_nvdimm.size() == MaxHeapSize, "They all should be same");
232
233 // Reserve dram memory
234 char* base = os::attempt_reserve_memory_at(rs_dram.size(), rs_dram.base());
235 if (base != rs_dram.base()) {
236 if (base != NULL) {
237 os::release_memory(base, rs_dram.size());
238 }
239 log_error(gc, init)("Error in re-mapping memory on dram during G1 heterogenous memory initialization");
240 return false;
241 }
242
243 // We reserve and commit this entire space to NV-DIMM.
244 if (!map_nvdimm_space(rs_nvdimm)) {
245 log_error(gc, init)("Error in re-mapping memory to nv-dimm during G1 heterogenous memory initialization");
246 return false;
247 }
248
249 if (_region_granularity >= (_page_size * _commit_factor)) {
250 _dram_mapper = new G1RegionsLargerThanCommitSizeMapper(rs_dram, rs_dram.size(), _page_size, _region_granularity, _commit_factor, _type);
251 } else {
252 _dram_mapper = new G1RegionsSmallerThanCommitSizeMapper(rs_dram, rs_dram.size(), _page_size, _region_granularity, _commit_factor, _type);
253 }
254
255 _start_index_of_dram = (uint)(rs_nvdimm.size() / _region_granularity);
256 return true;
257 }
258
259 void G1RegionToHeteroSpaceMapper::commit_regions(uint start_idx, size_t num_regions, WorkGang* pretouch_gang) {
260 uint end_idx = (start_idx + (uint)num_regions - 1);
261
262 uint num_dram = end_idx >= _start_index_of_dram ? MIN2((end_idx - _start_index_of_dram + 1), (uint)num_regions) : 0;
263 uint num_nvdimm = (uint)num_regions - num_dram;
264
265 if (num_nvdimm > 0) {
266 // We do not need to commit nv-dimm regions, since they are committed in the beginning.
267 _num_committed_nvdimm += num_nvdimm;
268 }
269 if (num_dram > 0) {
270 _dram_mapper->commit_regions(start_idx > _start_index_of_dram ? (start_idx - _start_index_of_dram) : 0, num_dram, pretouch_gang);
271 _num_committed_dram += num_dram;
272 }
273 }
274
275 void G1RegionToHeteroSpaceMapper::uncommit_regions(uint start_idx, size_t num_regions) {
276 uint end_idx = (start_idx + (uint)num_regions - 1);
277 uint num_dram = end_idx >= _start_index_of_dram ? MIN2((end_idx - _start_index_of_dram + 1), (uint)num_regions) : 0;
278 uint num_nvdimm = (uint)num_regions - num_dram;
279
280 if (num_nvdimm > 0) {
281 // We do not uncommit memory for nv-dimm regions.
282 _num_committed_nvdimm -= num_nvdimm;
283 }
284
285 if (num_dram > 0) {
286 _dram_mapper->uncommit_regions(start_idx > _start_index_of_dram ? (start_idx - _start_index_of_dram) : 0, num_dram);
287 _num_committed_dram -= num_dram;
288 }
289 }
290
291 uint G1RegionToHeteroSpaceMapper::num_committed_dram() const {
292 return _num_committed_dram;
293 }
294
295 uint G1RegionToHeteroSpaceMapper::num_committed_nvdimm() const {
296 return _num_committed_nvdimm;
297 }
298
299 G1RegionToSpaceMapper* G1RegionToSpaceMapper::create_heap_mapper(ReservedSpace rs,
300 size_t actual_size,
301 size_t page_size,
302 size_t region_granularity,
303 size_t commit_factor,
304 MemoryType type) {
305 if (AllocateOldGenAt != NULL) {
306 G1RegionToHeteroSpaceMapper* mapper = new G1RegionToHeteroSpaceMapper(rs, actual_size, page_size, region_granularity, commit_factor, type);
307 if (!mapper->initialize()) {
308 delete mapper;
309 return NULL;
310 }
311 return (G1RegionToSpaceMapper*)mapper;
312 } else {
313 return create_mapper(rs, actual_size, page_size, region_granularity, commit_factor, type);
314 }
315 }
316
317 G1RegionToSpaceMapper* G1RegionToSpaceMapper::create_mapper(ReservedSpace rs,
318 size_t actual_size,
319 size_t page_size,
320 size_t region_granularity,
321 size_t commit_factor,
322 MemoryType type) {
323 if (region_granularity >= (page_size * commit_factor)) {
324 return new G1RegionsLargerThanCommitSizeMapper(rs, actual_size, page_size, region_granularity, commit_factor, type);
325 } else {
326 return new G1RegionsSmallerThanCommitSizeMapper(rs, actual_size, page_size, region_granularity, commit_factor, type);
327 }
328 }
329
330 void G1RegionToSpaceMapper::commit_and_set_special() {
331 _storage.commit_and_set_special();
332 }