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