1 /*
2 * Copyright (c) 2015, 2020, 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 #include "precompiled.hpp"
25 #include "gc/shared/gcLogPrecious.hpp"
26 #include "gc/z/zAddress.inline.hpp"
27 #include "gc/z/zArray.inline.hpp"
28 #include "gc/z/zGlobals.hpp"
29 #include "gc/z/zLargePages.inline.hpp"
30 #include "gc/z/zNUMA.inline.hpp"
31 #include "gc/z/zPhysicalMemory.inline.hpp"
32 #include "logging/log.hpp"
33 #include "runtime/globals.hpp"
34 #include "runtime/globals_extension.hpp"
35 #include "runtime/init.hpp"
36 #include "runtime/os.hpp"
37 #include "services/memTracker.hpp"
38 #include "utilities/align.hpp"
39 #include "utilities/debug.hpp"
40 #include "utilities/globalDefinitions.hpp"
41 #include "utilities/powerOfTwo.hpp"
42
43 ZPhysicalMemory::ZPhysicalMemory() :
44 _segments() {}
45
46 ZPhysicalMemory::ZPhysicalMemory(const ZPhysicalMemorySegment& segment) :
47 _segments() {
48 add_segment(segment);
49 }
50
51 ZPhysicalMemory::ZPhysicalMemory(const ZPhysicalMemory& pmem) :
52 _segments() {
53 add_segments(pmem);
54 }
55
56 const ZPhysicalMemory& ZPhysicalMemory::operator=(const ZPhysicalMemory& pmem) {
57 // Free segments
58 _segments.clear_and_deallocate();
59
60 // Copy segments
61 add_segments(pmem);
62
63 return *this;
64 }
65
66 size_t ZPhysicalMemory::size() const {
67 size_t size = 0;
68
69 for (int i = 0; i < _segments.length(); i++) {
70 size += _segments.at(i).size();
71 }
72
73 return size;
74 }
75
76 void ZPhysicalMemory::insert_segment(int index, uintptr_t start, size_t size, bool committed) {
77 _segments.insert_before(index, ZPhysicalMemorySegment(start, size, committed));
78 }
79
80 void ZPhysicalMemory::replace_segment(int index, uintptr_t start, size_t size, bool committed) {
81 _segments.at_put(index, ZPhysicalMemorySegment(start, size, committed));
82 }
83
84 void ZPhysicalMemory::remove_segment(int index) {
85 _segments.remove_at(index);
86 }
87
88 void ZPhysicalMemory::add_segments(const ZPhysicalMemory& pmem) {
89 for (int i = 0; i < pmem.nsegments(); i++) {
90 add_segment(pmem.segment(i));
91 }
92 }
93
94 void ZPhysicalMemory::remove_segments() {
95 _segments.clear_and_deallocate();
96 }
97
98 static bool is_mergable(const ZPhysicalMemorySegment& before, const ZPhysicalMemorySegment& after) {
99 return before.end() == after.start() && before.is_committed() == after.is_committed();
100 }
101
102 void ZPhysicalMemory::add_segment(const ZPhysicalMemorySegment& segment) {
103 // Insert segments in address order, merge segments when possible
104 for (int i = _segments.length(); i > 0; i--) {
105 const int current = i - 1;
106
107 if (_segments.at(current).end() <= segment.start()) {
108 if (is_mergable(_segments.at(current), segment)) {
109 if (current + 1 < _segments.length() && is_mergable(segment, _segments.at(current + 1))) {
110 // Merge with end of current segment and start of next segment
111 const size_t start = _segments.at(current).start();
112 const size_t size = _segments.at(current).size() + segment.size() + _segments.at(current + 1).size();
113 replace_segment(current, start, size, segment.is_committed());
114 remove_segment(current + 1);
115 return;
116 }
117
118 // Merge with end of current segment
119 const size_t start = _segments.at(current).start();
120 const size_t size = _segments.at(current).size() + segment.size();
121 replace_segment(current, start, size, segment.is_committed());
122 return;
123 } else if (current + 1 < _segments.length() && is_mergable(segment, _segments.at(current + 1))) {
124 // Merge with start of next segment
125 const size_t start = segment.start();
126 const size_t size = segment.size() + _segments.at(current + 1).size();
127 replace_segment(current + 1, start, size, segment.is_committed());
128 return;
129 }
130
131 // Insert after current segment
132 insert_segment(current + 1, segment.start(), segment.size(), segment.is_committed());
133 return;
134 }
135 }
136
137 if (_segments.length() > 0 && is_mergable(segment, _segments.at(0))) {
138 // Merge with start of first segment
139 const size_t start = segment.start();
140 const size_t size = segment.size() + _segments.at(0).size();
141 replace_segment(0, start, size, segment.is_committed());
142 return;
143 }
144
145 // Insert before first segment
146 insert_segment(0, segment.start(), segment.size(), segment.is_committed());
147 }
148
149 bool ZPhysicalMemory::commit_segment(int index, size_t size) {
150 ZPhysicalMemorySegment& segment = _segments.at(index);
151
152 assert(size <= segment.size(), "Invalid size");
153 assert(!segment.is_committed(), "Invalid state");
154
155 if (size == segment.size()) {
156 // Completely committed
157 segment.set_committed(true);
158 return true;
159 }
160
161 if (size > 0) {
162 // Partially committed, split segment
163 insert_segment(index + 1, segment.start() + size, segment.size() - size, false /* committed */);
164 replace_segment(index, segment.start(), size, true /* committed */);
165 }
166
167 return false;
168 }
169
170 bool ZPhysicalMemory::uncommit_segment(int index, size_t size) {
171 ZPhysicalMemorySegment& segment = _segments.at(index);
172
173 assert(size <= segment.size(), "Invalid size");
174 assert(segment.is_committed(), "Invalid state");
175
176 if (size == segment.size()) {
177 // Completely uncommitted
178 segment.set_committed(false);
179 return true;
180 }
181
182 if (size > 0) {
183 // Partially uncommitted, split segment
184 insert_segment(index + 1, segment.start() + size, segment.size() - size, true /* committed */);
185 replace_segment(index, segment.start(), size, false /* committed */);
186 }
187
188 return false;
189 }
190
191 ZPhysicalMemory ZPhysicalMemory::split(size_t size) {
192 ZPhysicalMemory pmem;
193 int nsegments = 0;
194
195 for (int i = 0; i < _segments.length(); i++) {
196 const ZPhysicalMemorySegment& segment = _segments.at(i);
197 if (pmem.size() < size) {
198 if (pmem.size() + segment.size() <= size) {
199 // Transfer segment
200 pmem.add_segment(segment);
201 } else {
202 // Split segment
203 const size_t split_size = size - pmem.size();
204 pmem.add_segment(ZPhysicalMemorySegment(segment.start(), split_size, segment.is_committed()));
205 _segments.at_put(nsegments++, ZPhysicalMemorySegment(segment.start() + split_size, segment.size() - split_size, segment.is_committed()));
206 }
207 } else {
208 // Keep segment
209 _segments.at_put(nsegments++, segment);
210 }
211 }
212
213 _segments.trunc_to(nsegments);
214
215 return pmem;
216 }
217
218 ZPhysicalMemory ZPhysicalMemory::split_committed() {
219 ZPhysicalMemory pmem;
220 int nsegments = 0;
221
222 for (int i = 0; i < _segments.length(); i++) {
223 const ZPhysicalMemorySegment& segment = _segments.at(i);
224 if (segment.is_committed()) {
225 // Transfer segment
226 pmem.add_segment(segment);
227 } else {
228 // Keep segment
229 _segments.at_put(nsegments++, segment);
230 }
231 }
232
233 _segments.trunc_to(nsegments);
234
235 return pmem;
236 }
237
238 ZPhysicalMemoryManager::ZPhysicalMemoryManager(size_t max_capacity) :
239 _backing(max_capacity) {
240 // Make the whole range free
241 _manager.free(0, max_capacity);
242 }
243
244 bool ZPhysicalMemoryManager::is_initialized() const {
245 return _backing.is_initialized();
246 }
247
248 void ZPhysicalMemoryManager::warn_commit_limits(size_t max_capacity) const {
249 _backing.warn_commit_limits(max_capacity);
250 }
251
252 void ZPhysicalMemoryManager::try_enable_uncommit(size_t min_capacity, size_t max_capacity) {
253 assert(!is_init_completed(), "Invalid state");
254
255 // If uncommit is not explicitly disabled, max capacity is greater than
256 // min capacity, and uncommit is supported by the platform, then uncommit
257 // will be enabled.
258 if (!ZUncommit) {
259 log_info_p(gc, init)("Uncommit: Disabled");
260 return;
261 }
262
263 if (max_capacity == min_capacity) {
264 log_info_p(gc, init)("Uncommit: Implicitly Disabled (-Xms equals -Xmx)");
265 FLAG_SET_ERGO(ZUncommit, false);
266 return;
267 }
268
269 // Test if uncommit is supported by the operating system by committing
270 // and then uncommitting a granule.
271 ZPhysicalMemory pmem(ZPhysicalMemorySegment(0, ZGranuleSize, false /* committed */));
272 if (!commit(pmem) || !uncommit(pmem)) {
273 log_info_p(gc, init)("Uncommit: Implicitly Disabled (Not supported by operating system)");
274 FLAG_SET_ERGO(ZUncommit, false);
275 return;
276 }
277
278 log_info_p(gc, init)("Uncommit: Enabled");
279 log_info_p(gc, init)("Uncommit Delay: " UINTX_FORMAT "s", ZUncommitDelay);
280 }
281
282 void ZPhysicalMemoryManager::nmt_commit(uintptr_t offset, size_t size) const {
283 // From an NMT point of view we treat the first heap view (marked0) as committed
284 const uintptr_t addr = ZAddress::marked0(offset);
285 MemTracker::record_virtual_memory_commit((void*)addr, size, CALLER_PC);
286 }
287
288 void ZPhysicalMemoryManager::nmt_uncommit(uintptr_t offset, size_t size) const {
289 if (MemTracker::tracking_level() > NMT_minimal) {
290 const uintptr_t addr = ZAddress::marked0(offset);
291 Tracker tracker(Tracker::uncommit);
292 tracker.record((address)addr, size);
293 }
294 }
295
296 void ZPhysicalMemoryManager::alloc(ZPhysicalMemory& pmem, size_t size) {
297 assert(is_aligned(size, ZGranuleSize), "Invalid size");
298
299 // Allocate segments
300 while (size > 0) {
301 size_t allocated = 0;
302 const uintptr_t start = _manager.alloc_from_front_at_most(size, &allocated);
303 assert(start != UINTPTR_MAX, "Allocation should never fail");
304 pmem.add_segment(ZPhysicalMemorySegment(start, allocated, false /* committed */));
305 size -= allocated;
306 }
307 }
308
309 void ZPhysicalMemoryManager::free(const ZPhysicalMemory& pmem) {
310 // Free segments
311 for (int i = 0; i < pmem.nsegments(); i++) {
312 const ZPhysicalMemorySegment& segment = pmem.segment(i);
313 _manager.free(segment.start(), segment.size());
314 }
315 }
316
317 bool ZPhysicalMemoryManager::commit(ZPhysicalMemory& pmem) {
318 // Commit segments
319 for (int i = 0; i < pmem.nsegments(); i++) {
320 const ZPhysicalMemorySegment& segment = pmem.segment(i);
321 if (segment.is_committed()) {
322 // Segment already committed
323 continue;
324 }
325
326 // Commit segment
327 const size_t committed = _backing.commit(segment.start(), segment.size());
328 if (!pmem.commit_segment(i, committed)) {
329 // Failed or partially failed
330 return false;
331 }
332 }
333
334 // Success
335 return true;
336 }
337
338 bool ZPhysicalMemoryManager::uncommit(ZPhysicalMemory& pmem) {
339 // Commit segments
340 for (int i = 0; i < pmem.nsegments(); i++) {
341 const ZPhysicalMemorySegment& segment = pmem.segment(i);
342 if (!segment.is_committed()) {
343 // Segment already uncommitted
344 continue;
345 }
346
347 // Uncommit segment
348 const size_t uncommitted = _backing.uncommit(segment.start(), segment.size());
349 if (!pmem.uncommit_segment(i, uncommitted)) {
350 // Failed or partially failed
351 return false;
352 }
353 }
354
355 // Success
356 return true;
357 }
358
359 void ZPhysicalMemoryManager::pretouch_view(uintptr_t addr, size_t size) const {
360 const size_t page_size = ZLargePages::is_explicit() ? ZGranuleSize : os::vm_page_size();
361 os::pretouch_memory((void*)addr, (void*)(addr + size), page_size);
362 }
363
364 void ZPhysicalMemoryManager::map_view(uintptr_t addr, const ZPhysicalMemory& pmem) const {
365 size_t size = 0;
366
367 // Map segments
368 for (int i = 0; i < pmem.nsegments(); i++) {
369 const ZPhysicalMemorySegment& segment = pmem.segment(i);
370 _backing.map(addr + size, segment.size(), segment.start());
371 size += segment.size();
372 }
373
374 // Setup NUMA interleaving for large pages
375 if (ZNUMA::is_enabled() && ZLargePages::is_explicit()) {
376 // To get granule-level NUMA interleaving when using large pages,
377 // we simply let the kernel interleave the memory for us at page
378 // fault time.
379 os::numa_make_global((char*)addr, size);
380 }
381 }
382
383 void ZPhysicalMemoryManager::unmap_view(uintptr_t addr, size_t size) const {
384 _backing.unmap(addr, size);
385 }
386
387 void ZPhysicalMemoryManager::pretouch(uintptr_t offset, size_t size) const {
388 if (ZVerifyViews) {
389 // Pre-touch good view
390 pretouch_view(ZAddress::good(offset), size);
391 } else {
392 // Pre-touch all views
393 pretouch_view(ZAddress::marked0(offset), size);
394 pretouch_view(ZAddress::marked1(offset), size);
395 pretouch_view(ZAddress::remapped(offset), size);
396 }
397 }
398
399 void ZPhysicalMemoryManager::map(uintptr_t offset, const ZPhysicalMemory& pmem) const {
400 const size_t size = pmem.size();
401
402 if (ZVerifyViews) {
403 // Map good view
404 map_view(ZAddress::good(offset), pmem);
405 } else {
406 // Map all views
407 map_view(ZAddress::marked0(offset), pmem);
408 map_view(ZAddress::marked1(offset), pmem);
409 map_view(ZAddress::remapped(offset), pmem);
410 }
411
412 nmt_commit(offset, size);
413 }
414
415 void ZPhysicalMemoryManager::unmap(uintptr_t offset, size_t size) const {
416 nmt_uncommit(offset, size);
417
418 if (ZVerifyViews) {
419 // Unmap good view
420 unmap_view(ZAddress::good(offset), size);
421 } else {
422 // Unmap all views
423 unmap_view(ZAddress::marked0(offset), size);
424 unmap_view(ZAddress::marked1(offset), size);
425 unmap_view(ZAddress::remapped(offset), size);
426 }
427 }
428
429 void ZPhysicalMemoryManager::debug_map(uintptr_t offset, const ZPhysicalMemory& pmem) const {
430 // Map good view
431 assert(ZVerifyViews, "Should be enabled");
432 map_view(ZAddress::good(offset), pmem);
433 }
434
435 void ZPhysicalMemoryManager::debug_unmap(uintptr_t offset, size_t size) const {
436 // Unmap good view
437 assert(ZVerifyViews, "Should be enabled");
438 unmap_view(ZAddress::good(offset), size);
439 }