1 /*
2 * Copyright (c) 2017, 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 "jfr/recorder/storage/jfrVirtualMemory.hpp"
27 #include "jfr/utilities/align.hpp"
28 #include "runtime/virtualspace.hpp"
29 #include "runtime/orderAccess.inline.hpp"
30 #include "runtime/os.hpp"
31 #include "services/memTracker.hpp"
32 #include "utilities/globalDefinitions.hpp"
33
34 /*
35 * A memory segment represents a virtual memory reservation.
36 * It provides ways to commit and decommit physical storage
37 * onto its virtual memory reservation.
38 */
39
40 class JfrVirtualMemorySegment : public JfrCHeapObj {
41 friend class JfrVirtualMemoryManager;
42 private:
43 JfrVirtualMemorySegment* _next;
44 char* _top;
45 ReservedSpace _rs;
46 VirtualSpace _virtual_memory;
47
48 // Convenience functions to access the underlying virtual space metadata
49 const u1* committed_low() const { return (const u1*)_virtual_memory.low(); }
50 const u1* committed_high() const { return (const u1*)_virtual_memory.high(); }
51 const u1* reserved_low() const { return (const u1*)_virtual_memory.low_boundary(); }
52 const u1* reserved_high() const { return (const u1*)_virtual_memory.high_boundary(); }
53 size_t reserved_words() const { return _virtual_memory.reserved_size() / BytesPerWord; }
54 size_t committed_words() const { return _virtual_memory.actual_committed_size() / BytesPerWord; }
55 bool is_pre_committed() const { return _virtual_memory.special(); }
56 VirtualSpace& virtual_space() { return _virtual_memory; }
57
58 JfrVirtualMemorySegment();
59 ~JfrVirtualMemorySegment();
60
61 JfrVirtualMemorySegment* next() const { return _next; }
62 void set_next(JfrVirtualMemorySegment* v) { _next = v; }
63
64 // Returns true if requested size is available in the committed area
65 bool is_available(size_t block_size_request_words) {
66 return block_size_request_words <= pointer_delta(committed_high(), _top, sizeof(char*));
67 }
68
69 // allocation pointer committed memory
70 char* top() const { return _top; }
71 void inc_top(size_t size_in_words) {
72 assert(is_available(size_in_words), "invariant");
73 _top += size_in_words * BytesPerWord;
74 assert(_top <= _virtual_memory.high(), "invariant");
75 }
76
77 // initialization is the virtual memory reservation
78 bool initialize(size_t reservation_size_request_bytes);
79 void* take_from_committed(size_t block_size_request_words);
80
81 // Returns committed memory
82 void* commit(size_t block_size_request_words) {
83 return take_from_committed(block_size_request_words);
84 }
85
86 // Commit more memory in a reservation
87 bool expand_by(size_t block_size_request_words);
88
89 // Decommits all committed memory in this reservation segment.
90 void decommit();
91 };
92
93 JfrVirtualMemorySegment::JfrVirtualMemorySegment() :
94 _next(NULL),
95 _top(NULL),
96 _rs(),
97 _virtual_memory() {}
98
99 JfrVirtualMemorySegment::~JfrVirtualMemorySegment() {
100 decommit();
101 _rs.release();
102 }
103
104 bool JfrVirtualMemorySegment::initialize(size_t reservation_size_request_bytes) {
105 assert(is_aligned(reservation_size_request_bytes, os::vm_allocation_granularity()), "invariant");
106 _rs = ReservedSpace(reservation_size_request_bytes,
107 os::vm_allocation_granularity(),
108 UseLargePages && os::can_commit_large_page_memory(),
109 false);
110 if (!_rs.is_reserved()) {
111 return false;
112 }
113 assert(_rs.base() != NULL, "invariant");
114 assert(_rs.size() != 0, "invariant");
115 assert(is_aligned(_rs.base(), os::vm_allocation_granularity()), "invariant");
116 assert(is_aligned(_rs.size(), os::vm_allocation_granularity()), "invariant");
117 os::trace_page_sizes("Jfr", reservation_size_request_bytes,
118 reservation_size_request_bytes,
119 os::vm_page_size(),
120 _rs.base(),
121 _rs.size());
122 MemTracker::record_virtual_memory_type((address)_rs.base(), mtTracing);
123 assert(is_aligned(_rs.base(), os::vm_page_size()), "invariant");
124 assert(is_aligned(_rs.size(), os::vm_page_size()), "invariant");
125
126 // ReservedSpaces marked as special will have the entire memory
127 // pre-committed. Setting a committed size will make sure that
128 // committed_size and actual_committed_size agrees.
129 const size_t pre_committed_size = _rs.special() ? _rs.size() : 0;
130 const bool result = virtual_space().initialize_with_granularity(_rs, pre_committed_size, os::vm_page_size());
131
132 if (result) {
133 assert(virtual_space().committed_size() == virtual_space().actual_committed_size(),
134 "Checking that the pre-committed memory was registered by the VirtualSpace");
135 _top = virtual_space().low();
136 }
137 return result;
138 }
139
140 bool JfrVirtualMemorySegment::expand_by(size_t block_size_request_words) {
141 size_t block_size_request_bytes = block_size_request_words * BytesPerWord;
142 const size_t uncommitted = virtual_space().reserved_size() - virtual_space().actual_committed_size();
143 if (uncommitted < block_size_request_bytes) {
144 // commit whatever is left in the reservation
145 block_size_request_bytes = uncommitted;
146 }
147 assert(is_aligned(block_size_request_bytes, os::vm_allocation_granularity()), "invariant");
148 // commit block in reserved memory
149 bool result = virtual_space().expand_by(block_size_request_bytes, false);
150 assert(result, "Failed to commit memory");
151 return result;
152 }
153
154 void JfrVirtualMemorySegment::decommit() {
155 assert(_virtual_memory.committed_size() == _virtual_memory.actual_committed_size(),
156 "The committed memory doesn't match the expanded memory.");
157
158 const size_t committed_size = virtual_space().actual_committed_size();
159 if (committed_size > 0) {
160 virtual_space().shrink_by(committed_size);
161 }
162
163 assert(_virtual_memory.actual_committed_size() == 0, "invariant");
164 }
165
166 // Attempt to get a committed block
167 void* JfrVirtualMemorySegment::take_from_committed(size_t block_size_request_words) {
168 // The virtual spaces are always expanded by the
169 // commit granularity to enforce the following condition.
170 // Without this the is_available check will not work correctly.
171 assert(_virtual_memory.committed_size() == _virtual_memory.actual_committed_size(),
172 "The committed memory doesn't match the expanded memory.");
173 if (!is_available(block_size_request_words)) {
174 return NULL;
175 }
176 void* const block = top();
177 assert(block != NULL, "invariant");
178 inc_top(block_size_request_words);
179 return block;
180 }
181
182 class JfrVirtualMemoryManager : public JfrCHeapObj {
183 typedef JfrVirtualMemorySegment Segment;
184 private:
185 Segment* _segments;
186 Segment* _current_segment;
187 size_t _reservation_size_request_words;
188 size_t _reservation_size_request_limit_words; // total reservation limit
189
190 // Sum of reserved and committed memory in the segments
191 size_t _current_reserved_words;
192 size_t _current_committed_words;
193
194 void link(Segment* segment);
195 Segment* current();
196
197 void inc_reserved_words(size_t words);
198 void inc_committed_words(size_t words);
199
200 bool new_segment(size_t reservation_size_request_words);
201
202 bool expand_segment_by(Segment* segment, size_t block_size_request_words);
203
204 bool expand_by(size_t block_size_request_words, size_t reservation_size_request_words);
205 bool can_reserve() const;
206
207 public:
208 JfrVirtualMemoryManager();
209 ~JfrVirtualMemoryManager();
210
211 bool initialize(size_t reservation_size_request_words, size_t segment_count = 1);
212 void* commit(size_t requested_block_size_words);
213
214 bool is_full() const {
215 return reserved_high() == committed_high();
216 }
217
218 const u1* committed_low() const { return _current_segment->committed_low(); }
219 const u1* committed_high() const { return _current_segment->committed_high(); }
220 const u1* reserved_low() const { return _current_segment->reserved_low(); }
221 const u1* reserved_high() const { return _current_segment->reserved_high(); }
222 };
223
224 JfrVirtualMemoryManager::JfrVirtualMemoryManager() :
225 _segments(NULL),
226 _current_segment(NULL),
227 _reservation_size_request_words(0),
228 _reservation_size_request_limit_words(0),
229 _current_reserved_words(0),
230 _current_committed_words(0) {}
231
232 JfrVirtualMemoryManager::~JfrVirtualMemoryManager() {
233 JfrVirtualMemorySegment* segment = _segments;
234 while (segment != NULL) {
235 JfrVirtualMemorySegment* next_segment = segment->next();
236 delete segment;
237 segment = next_segment;
238 }
239 }
240
241 // for now only allow a singleton segment per virtual memory client
242 bool JfrVirtualMemoryManager::initialize(size_t reservation_size_request_words, size_t segment_count /* 1 */) {
243 assert(is_aligned(reservation_size_request_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");
244 _reservation_size_request_words = reservation_size_request_words;
245 assert(segment_count > 0, "invariant");
246 _reservation_size_request_limit_words = reservation_size_request_words * segment_count;
247 assert(is_aligned(_reservation_size_request_limit_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");
248 return new_segment(_reservation_size_request_words);
249 }
250
251 bool JfrVirtualMemoryManager::can_reserve() const {
252 return _reservation_size_request_limit_words == 0 ? true : _current_reserved_words < _reservation_size_request_limit_words;
253 }
254
255 // Allocate another segment and add it to the list.
256 bool JfrVirtualMemoryManager::new_segment(size_t reservation_size_request_words) {
257 assert(reservation_size_request_words > 0, "invariant");
258 assert(is_aligned(reservation_size_request_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");
259 Segment* segment = new Segment();
260 if (NULL == segment) {
261 return false;
262 }
263 if (!segment->initialize(reservation_size_request_words * BytesPerWord)) {
264 delete segment;
265 return false;
266 }
267 assert(segment->reserved_words() == reservation_size_request_words,
268 "Actual reserved memory size differs from requested reservation memory size");
269 link(segment);
270 return true;
271 }
272
273 bool JfrVirtualMemoryManager::expand_segment_by(JfrVirtualMemorySegment* segment, size_t block_size_request_words) {
274 assert(segment != NULL, "invariant");
275 const size_t before = segment->committed_words();
276 const bool result = segment->expand_by(block_size_request_words);
277 const size_t after = segment->committed_words();
278 // after and before can be the same if the memory was pre-committed.
279 assert(after >= before, "Inconsistency");
280 inc_committed_words(after - before);
281 return result;
282 }
283
284 void JfrVirtualMemoryManager::inc_reserved_words(size_t words) {
285 _current_reserved_words += words;
286 }
287
288 JfrVirtualMemorySegment* JfrVirtualMemoryManager::current() {
289 return _current_segment;
290 }
291
292 void JfrVirtualMemoryManager::inc_committed_words(size_t words) {
293 _current_committed_words += words;
294 }
295
296 bool JfrVirtualMemoryManager::expand_by(size_t block_size_request_words, size_t reservation_size_request_words) {
297 assert(is_aligned(block_size_request_words * BytesPerWord, os::vm_page_size()), "invariant");
298 assert(is_aligned(block_size_request_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");
299 assert(is_aligned(reservation_size_request_words * BytesPerWord, os::vm_page_size()), "invariant");
300 assert(is_aligned(reservation_size_request_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");
301 assert(block_size_request_words <= reservation_size_request_words, "invariant");
302 // Attempt to commit more memory from the the current virtual space reservation.
303 if (expand_segment_by(current(), block_size_request_words)) {
304 return true;
305 }
306
307 // reached limit of what is allowed to be reserved?
308 if (!can_reserve()) {
309 return false;
310 }
311
312 // Get another segment.
313 if (!new_segment(reservation_size_request_words)) {
314 return false;
315 }
316
317 if (current()->is_pre_committed()) {
318 // The memory was pre-committed, so we are done here.
319 assert(block_size_request_words <= current()->committed_words(),
320 "The new VirtualSpace was pre-committed, so it"
321 "should be large enough to fit the alloc request.");
322 return true;
323 }
324 return expand_segment_by(current(), block_size_request_words);
325 }
326
327 void JfrVirtualMemoryManager::link(JfrVirtualMemorySegment* segment) {
328 assert(segment != NULL, "invariant");
329 if (_segments == NULL) {
330 _segments = segment;
331 } else {
332 assert(_current_segment != NULL, "invariant");
333 assert(_segments == _current_segment, "invariant");
334 _current_segment->set_next(segment);
335 }
336 _current_segment = segment;
337 inc_reserved_words(segment->reserved_words());
338 inc_committed_words(segment->committed_words());
339 }
340
341 void* JfrVirtualMemoryManager::commit(size_t block_size_request_words) {
342 assert(is_aligned(block_size_request_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");
343 void* block = current()->commit(block_size_request_words);
344 if (block != NULL) {
345 return block;
346 }
347 assert(block == NULL, "invariant");
348 if (is_full()) {
349 return NULL;
350 }
351 assert(block_size_request_words <= _reservation_size_request_words, "invariant");
352 if (expand_by(block_size_request_words, _reservation_size_request_words)) {
353 block = current()->commit(block_size_request_words);
354 assert(block != NULL, "The allocation was expected to succeed after the expansion");
355 }
356 return block;
357 }
358
359 JfrVirtualMemory::JfrVirtualMemory() :
360 _vmm(NULL),
361 _reserved_low(),
362 _reserved_high(),
363 _top(NULL),
364 _commit_point(NULL),
365 _physical_commit_size_request_words(0),
366 _aligned_datum_size_bytes(0) {}
367
368 JfrVirtualMemory::~JfrVirtualMemory() {
369 assert(_vmm != NULL, "invariant");
370 delete _vmm;
371 }
372
373 size_t JfrVirtualMemory::aligned_datum_size_bytes() const {
374 return _aligned_datum_size_bytes;
375 }
376
377 static void adjust_allocation_ratio(size_t* const reservation_size_bytes, size_t* const commit_size_bytes) {
378 assert(reservation_size_bytes != NULL, "invariant");
379 assert(*reservation_size_bytes > 0, "invariant");
380 assert(commit_size_bytes != NULL, "invariant");
381 assert(*commit_size_bytes > 0, "invariant");
382 assert(*reservation_size_bytes >= *commit_size_bytes, "invariant");
383 assert(is_aligned(*reservation_size_bytes, os::vm_allocation_granularity()), "invariant");
384 assert(is_aligned(*commit_size_bytes, os::vm_allocation_granularity()), "invariant");
385
386 size_t reservation_size_units = *reservation_size_bytes / os::vm_allocation_granularity();
387 size_t commit_size_units = *commit_size_bytes / os::vm_allocation_granularity();
388 assert(reservation_size_units > 0, "invariant");
389 assert(commit_size_units > 0, "invariant");
390
391 size_t original_ratio_units = reservation_size_units / commit_size_units;
392 size_t rem = reservation_size_units % commit_size_units;
393 assert(original_ratio_units > 0, "invariant");
394
395 if (rem > 0) {
396 reservation_size_units -= rem % original_ratio_units;
397 commit_size_units += rem / original_ratio_units;
398 }
399
400 assert(commit_size_units > 0, "invariant");
401 assert(reservation_size_units % original_ratio_units == 0, "invariant");
402 assert(original_ratio_units * commit_size_units == reservation_size_units , "invariant");
403 assert(original_ratio_units == reservation_size_units / commit_size_units, "invariant");
404 *reservation_size_bytes = reservation_size_units * os::vm_allocation_granularity();
405 *commit_size_bytes = commit_size_units * os::vm_allocation_granularity();
406 assert((*reservation_size_bytes % *commit_size_bytes) == 0, "invariant");
407 }
408
409
410 void* JfrVirtualMemory::initialize(size_t reservation_size_request_bytes,
411 size_t block_size_request_bytes,
412 size_t datum_size_bytes /* 1 */) {
413 assert(_vmm == NULL, "invariant");
414 _vmm = new JfrVirtualMemoryManager();
415
416 if (_vmm == NULL) {
417 return NULL;
418 }
419
420 assert(reservation_size_request_bytes > 0, "invariant");
421 _aligned_datum_size_bytes = align_up(datum_size_bytes, BytesPerWord);
422 assert(is_aligned(_aligned_datum_size_bytes, BytesPerWord), "invariant");
423
424 reservation_size_request_bytes = ReservedSpace::allocation_align_size_up(reservation_size_request_bytes);
425 assert(is_aligned(reservation_size_request_bytes, os::vm_allocation_granularity()), "invariant");
426 assert(is_aligned(reservation_size_request_bytes, _aligned_datum_size_bytes), "invariant");
427 block_size_request_bytes = MAX2(block_size_request_bytes, (size_t)os::vm_allocation_granularity());
428 block_size_request_bytes = ReservedSpace::allocation_align_size_up(block_size_request_bytes);
429 assert(is_aligned(block_size_request_bytes, os::vm_allocation_granularity()), "invariant");
430 assert(is_aligned(block_size_request_bytes, _aligned_datum_size_bytes), "invariant");
431 // adjustment to valid ratio in units of vm_allocation_granularity
432 adjust_allocation_ratio(&reservation_size_request_bytes, &block_size_request_bytes);
433 assert(is_aligned(reservation_size_request_bytes, os::vm_allocation_granularity()), "invariant");
434 assert(is_aligned(reservation_size_request_bytes, _aligned_datum_size_bytes), "invariant");
435 assert(is_aligned(block_size_request_bytes, os::vm_allocation_granularity()), "invariant");
436 assert(is_aligned(block_size_request_bytes, _aligned_datum_size_bytes), "invariant");
437 assert((reservation_size_request_bytes % block_size_request_bytes) == 0, "invariant");
438 const size_t reservation_size_request_words = reservation_size_request_bytes / BytesPerWord;
439 _physical_commit_size_request_words = block_size_request_bytes / BytesPerWord;
440 // virtual memory reservation
441 if (!_vmm->initialize(reservation_size_request_words)) {
442 // is implicitly "full" if reservation fails
443 assert(is_full(), "invariant");
444 return NULL;
445 }
446 _reserved_low = (const u1*)_vmm->reserved_low();
447 _reserved_high = (const u1*)_vmm->reserved_high();
448 // reservation complete
449 _top = (u1*)_vmm->committed_high();
450 _commit_point = _top;
451 assert(_reserved_low == _top, "invariant"); // initial empty state
452 assert((size_t)(_reserved_high - _reserved_low) == reservation_size_request_bytes, "invariant");
453 // initial commit
454 commit_memory_block();
455 return _top;
456 }
457
458 void* JfrVirtualMemory::commit(size_t block_size_request_words) {
459 assert(_vmm != NULL, "invariant");
460 assert(is_aligned(block_size_request_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");
461 return _vmm->commit(block_size_request_words);
462 }
463
464 bool JfrVirtualMemory::is_full() const {
465 return _top == _reserved_high;
466 }
467
468 bool JfrVirtualMemory::is_empty() const {
469 return _top == _reserved_low;
470 }
471
472 bool JfrVirtualMemory::commit_memory_block() {
473 assert(_vmm != NULL, "invariant");
474 assert(!is_full(), "invariant");
475 assert(_top == _commit_point, "invariant");
476
477 void* const block = _vmm->commit(_physical_commit_size_request_words);
478 if (block != NULL) {
479 _commit_point = _vmm->committed_high();
480 return true;
481 }
482 // all reserved virtual memory is committed
483 assert(block == NULL, "invariant");
484 assert(_vmm->reserved_high() == _vmm->committed_high(), "invariant");
485 return false;
486 }
487
488 void* JfrVirtualMemory::new_datum() {
489 assert(_vmm != NULL, "invariant");
490 assert(!is_full(), "invariant");
491 if (_top == _commit_point) {
492 if (!commit_memory_block()) {
493 assert(is_full(), "invariant");
494 return NULL;
495 }
496 }
497 assert(_top + _aligned_datum_size_bytes <= _commit_point, "invariant");
498 u1* allocation = _top;
499 _top += _aligned_datum_size_bytes;
500 assert(is_aligned(allocation, _aligned_datum_size_bytes), "invariant");
501 return allocation;
502 }
503
504 void* JfrVirtualMemory::index_ptr(size_t index) {
505 assert((index * _aligned_datum_size_bytes) + _reserved_low < _commit_point, "invariant");
506 return (void*)((index * _aligned_datum_size_bytes) + _reserved_low);
507 }
508
509 void* JfrVirtualMemory::get(size_t index) {
510 return index_ptr(index);
511 }
512
513 size_t JfrVirtualMemory::count() const {
514 return (_top - _reserved_low) / _aligned_datum_size_bytes;
515 }
516
517 size_t JfrVirtualMemory::live_set() const {
518 return _top - _reserved_low;
519 }
520
521 size_t JfrVirtualMemory::reserved_size() const {
522 return _reserved_high - _reserved_low;
523 }
524
525 bool JfrVirtualMemory::compact(size_t index) {
526 assert(index > 0, "invariant");
527 assert(index <= reserved_size(), "invariant");
528 const u1* low = static_cast<u1*>(index_ptr(index));
529 const size_t block_size = _top - low;
530 memcpy(const_cast<u1*>(_reserved_low), low, block_size);
531 _top = const_cast<u1*>(_reserved_low) + block_size;
532 assert(live_set() == block_size, "invariant");
533 return true;
534 }