1 /*
2 * Copyright (c) 2017, 2018, 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 "memory/virtualspace.hpp"
28 #include "runtime/globals.hpp"
29 #include "runtime/os.hpp"
30 #include "services/memTracker.hpp"
31 #include "utilities/globalDefinitions.hpp"
32
33 /*
34 * A memory segment represents a virtual memory reservation.
35 * It provides ways to commit and decommit physical storage
36 * onto its virtual memory reservation.
37 */
38
39 class JfrVirtualMemorySegment : public JfrCHeapObj {
40 friend class JfrVirtualMemoryManager;
41 private:
42 JfrVirtualMemorySegment* _next;
43 char* _top;
44 ReservedSpace _rs;
45 VirtualSpace _virtual_memory;
46
47 // Convenience functions to access the underlying virtual space metadata
48 const u1* committed_low() const { return (const u1*)_virtual_memory.low(); }
49 const u1* committed_high() const { return (const u1*)_virtual_memory.high(); }
50 const u1* reserved_low() const { return (const u1*)_virtual_memory.low_boundary(); }
51 const u1* reserved_high() const { return (const u1*)_virtual_memory.high_boundary(); }
52 size_t reserved_words() const { return _virtual_memory.reserved_size() / BytesPerWord; }
53 size_t committed_words() const { return _virtual_memory.actual_committed_size() / BytesPerWord; }
54 bool is_pre_committed() const { return _virtual_memory.special(); }
55 VirtualSpace& virtual_space() { return _virtual_memory; }
56
57 JfrVirtualMemorySegment();
58 ~JfrVirtualMemorySegment();
59
60 JfrVirtualMemorySegment* next() const { return _next; }
61 void set_next(JfrVirtualMemorySegment* v) { _next = v; }
62
63 // Returns true if requested size is available in the committed area
64 bool is_available(size_t block_size_request_words) {
65 return block_size_request_words <= pointer_delta(committed_high(), _top, sizeof(char*));
66 }
67
68 // allocation pointer committed memory
69 char* top() const { return _top; }
70 void inc_top(size_t size_in_words) {
71 assert(is_available(size_in_words), "invariant");
72 _top += size_in_words * BytesPerWord;
73 assert(_top <= _virtual_memory.high(), "invariant");
74 }
75
76 // initialization is the virtual memory reservation
77 bool initialize(size_t reservation_size_request_bytes);
78 void* take_from_committed(size_t block_size_request_words);
79
80 // Returns committed memory
81 void* commit(size_t block_size_request_words) {
82 return take_from_committed(block_size_request_words);
83 }
84
85 // Commit more memory in a reservation
86 bool expand_by(size_t block_size_request_words);
87
88 // Decommits all committed memory in this reservation segment.
89 void decommit();
90 };
91
92 JfrVirtualMemorySegment::JfrVirtualMemorySegment() :
93 _next(NULL),
94 _top(NULL),
95 _rs(),
96 _virtual_memory() {}
97
98 JfrVirtualMemorySegment::~JfrVirtualMemorySegment() {
99 decommit();
100 _rs.release();
101 }
102
103 bool JfrVirtualMemorySegment::initialize(size_t reservation_size_request_bytes) {
104 assert(is_aligned(reservation_size_request_bytes, os::vm_allocation_granularity()), "invariant");
105 _rs = ReservedSpace(reservation_size_request_bytes,
106 os::vm_allocation_granularity(),
107 UseLargePages && os::can_commit_large_page_memory());
108 if (!_rs.is_reserved()) {
109 return false;
110 }
111 assert(_rs.base() != NULL, "invariant");
112 assert(_rs.size() != 0, "invariant");
113 assert(is_aligned(_rs.base(), os::vm_allocation_granularity()), "invariant");
114 assert(is_aligned(_rs.size(), os::vm_allocation_granularity()), "invariant");
115 os::trace_page_sizes("Jfr", reservation_size_request_bytes,
116 reservation_size_request_bytes,
117 os::vm_page_size(),
118 _rs.base(),
119 _rs.size());
120 MemTracker::record_virtual_memory_type((address)_rs.base(), mtTracing);
121 assert(is_aligned(_rs.base(), os::vm_page_size()), "invariant");
122 assert(is_aligned(_rs.size(), os::vm_page_size()), "invariant");
123
124 // ReservedSpaces marked as special will have the entire memory
125 // pre-committed. Setting a committed size will make sure that
126 // committed_size and actual_committed_size agrees.
127 const size_t pre_committed_size = _rs.special() ? _rs.size() : 0;
128 const bool result = virtual_space().initialize_with_granularity(_rs, pre_committed_size, os::vm_page_size());
129
130 if (result) {
131 assert(virtual_space().committed_size() == virtual_space().actual_committed_size(),
132 "Checking that the pre-committed memory was registered by the VirtualSpace");
133 _top = virtual_space().low();
134 }
135 return result;
136 }
137
138 bool JfrVirtualMemorySegment::expand_by(size_t block_size_request_words) {
139 size_t block_size_request_bytes = block_size_request_words * BytesPerWord;
140 const size_t uncommitted = virtual_space().reserved_size() - virtual_space().actual_committed_size();
141 if (uncommitted < block_size_request_bytes) {
142 // commit whatever is left in the reservation
143 block_size_request_bytes = uncommitted;
144 }
145 assert(is_aligned(block_size_request_bytes, os::vm_allocation_granularity()), "invariant");
146 // commit block in reserved memory
147 bool result = virtual_space().expand_by(block_size_request_bytes, false);
148 assert(result, "Failed to commit memory");
149 return result;
150 }
151
152 void JfrVirtualMemorySegment::decommit() {
153 assert(_virtual_memory.committed_size() == _virtual_memory.actual_committed_size(),
154 "The committed memory doesn't match the expanded memory.");
155
156 const size_t committed_size = virtual_space().actual_committed_size();
157 if (committed_size > 0) {
158 virtual_space().shrink_by(committed_size);
159 }
160
161 assert(_virtual_memory.actual_committed_size() == 0, "invariant");
162 }
163
164 // Attempt to get a committed block
165 void* JfrVirtualMemorySegment::take_from_committed(size_t block_size_request_words) {
166 // The virtual spaces are always expanded by the
167 // commit granularity to enforce the following condition.
168 // Without this the is_available check will not work correctly.
169 assert(_virtual_memory.committed_size() == _virtual_memory.actual_committed_size(),
170 "The committed memory doesn't match the expanded memory.");
171 if (!is_available(block_size_request_words)) {
172 return NULL;
173 }
174 void* const block = top();
175 assert(block != NULL, "invariant");
176 inc_top(block_size_request_words);
177 return block;
178 }
179
180 class JfrVirtualMemoryManager : public JfrCHeapObj {
181 typedef JfrVirtualMemorySegment Segment;
182 private:
183 Segment* _segments;
184 Segment* _current_segment;
185 size_t _reservation_size_request_words;
186 size_t _reservation_size_request_limit_words; // total reservation limit
187
188 // Sum of reserved and committed memory in the segments
189 size_t _current_reserved_words;
190 size_t _current_committed_words;
191
192 void link(Segment* segment);
193 Segment* current();
194
195 void inc_reserved_words(size_t words);
196 void inc_committed_words(size_t words);
197
198 bool new_segment(size_t reservation_size_request_words);
199
200 bool expand_segment_by(Segment* segment, size_t block_size_request_words);
201
202 bool expand_by(size_t block_size_request_words, size_t reservation_size_request_words);
203 bool can_reserve() const;
204
205 public:
206 JfrVirtualMemoryManager();
207 ~JfrVirtualMemoryManager();
208
209 bool initialize(size_t reservation_size_request_words, size_t segment_count = 1);
210 void* commit(size_t requested_block_size_words);
211
212 bool is_full() const {
213 return reserved_high() == committed_high();
214 }
215
216 const u1* committed_low() const { return _current_segment->committed_low(); }
217 const u1* committed_high() const { return _current_segment->committed_high(); }
218 const u1* reserved_low() const { return _current_segment->reserved_low(); }
219 const u1* reserved_high() const { return _current_segment->reserved_high(); }
220 };
221
222 JfrVirtualMemoryManager::JfrVirtualMemoryManager() :
223 _segments(NULL),
224 _current_segment(NULL),
225 _reservation_size_request_words(0),
226 _reservation_size_request_limit_words(0),
227 _current_reserved_words(0),
228 _current_committed_words(0) {}
229
230 JfrVirtualMemoryManager::~JfrVirtualMemoryManager() {
231 JfrVirtualMemorySegment* segment = _segments;
232 while (segment != NULL) {
233 JfrVirtualMemorySegment* next_segment = segment->next();
234 delete segment;
235 segment = next_segment;
236 }
237 }
238
239 // for now only allow a singleton segment per virtual memory client
240 bool JfrVirtualMemoryManager::initialize(size_t reservation_size_request_words, size_t segment_count /* 1 */) {
241 assert(is_aligned(reservation_size_request_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");
242 _reservation_size_request_words = reservation_size_request_words;
243 assert(segment_count > 0, "invariant");
244 _reservation_size_request_limit_words = reservation_size_request_words * segment_count;
245 assert(is_aligned(_reservation_size_request_limit_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");
246 return new_segment(_reservation_size_request_words);
247 }
248
249 bool JfrVirtualMemoryManager::can_reserve() const {
250 return _reservation_size_request_limit_words == 0 ? true : _current_reserved_words < _reservation_size_request_limit_words;
251 }
252
253 // Allocate another segment and add it to the list.
254 bool JfrVirtualMemoryManager::new_segment(size_t reservation_size_request_words) {
255 assert(reservation_size_request_words > 0, "invariant");
256 assert(is_aligned(reservation_size_request_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");
257 Segment* segment = new Segment();
258 if (NULL == segment) {
259 return false;
260 }
261 if (!segment->initialize(reservation_size_request_words * BytesPerWord)) {
262 delete segment;
263 return false;
264 }
265 assert(segment->reserved_words() == reservation_size_request_words,
266 "Actual reserved memory size differs from requested reservation memory size");
267 link(segment);
268 return true;
269 }
270
271 bool JfrVirtualMemoryManager::expand_segment_by(JfrVirtualMemorySegment* segment, size_t block_size_request_words) {
272 assert(segment != NULL, "invariant");
273 const size_t before = segment->committed_words();
274 const bool result = segment->expand_by(block_size_request_words);
275 const size_t after = segment->committed_words();
276 // after and before can be the same if the memory was pre-committed.
277 assert(after >= before, "Inconsistency");
278 inc_committed_words(after - before);
279 return result;
280 }
281
282 void JfrVirtualMemoryManager::inc_reserved_words(size_t words) {
283 _current_reserved_words += words;
284 }
285
286 JfrVirtualMemorySegment* JfrVirtualMemoryManager::current() {
287 return _current_segment;
288 }
289
290 void JfrVirtualMemoryManager::inc_committed_words(size_t words) {
291 _current_committed_words += words;
292 }
293
294 bool JfrVirtualMemoryManager::expand_by(size_t block_size_request_words, size_t reservation_size_request_words) {
295 assert(is_aligned(block_size_request_words * BytesPerWord, os::vm_page_size()), "invariant");
296 assert(is_aligned(block_size_request_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");
297 assert(is_aligned(reservation_size_request_words * BytesPerWord, os::vm_page_size()), "invariant");
298 assert(is_aligned(reservation_size_request_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");
299 assert(block_size_request_words <= reservation_size_request_words, "invariant");
300 // Attempt to commit more memory from the the current virtual space reservation.
301 if (expand_segment_by(current(), block_size_request_words)) {
302 return true;
303 }
304
305 // reached limit of what is allowed to be reserved?
306 if (!can_reserve()) {
307 return false;
308 }
309
310 // Get another segment.
311 if (!new_segment(reservation_size_request_words)) {
312 return false;
313 }
314
315 if (current()->is_pre_committed()) {
316 // The memory was pre-committed, so we are done here.
317 assert(block_size_request_words <= current()->committed_words(),
318 "The new VirtualSpace was pre-committed, so it"
319 "should be large enough to fit the alloc request.");
320 return true;
321 }
322 return expand_segment_by(current(), block_size_request_words);
323 }
324
325 void JfrVirtualMemoryManager::link(JfrVirtualMemorySegment* segment) {
326 assert(segment != NULL, "invariant");
327 if (_segments == NULL) {
328 _segments = segment;
329 } else {
330 assert(_current_segment != NULL, "invariant");
331 assert(_segments == _current_segment, "invariant");
332 _current_segment->set_next(segment);
333 }
334 _current_segment = segment;
335 inc_reserved_words(segment->reserved_words());
336 inc_committed_words(segment->committed_words());
337 }
338
339 void* JfrVirtualMemoryManager::commit(size_t block_size_request_words) {
340 assert(is_aligned(block_size_request_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");
341 void* block = current()->commit(block_size_request_words);
342 if (block != NULL) {
343 return block;
344 }
345 assert(block == NULL, "invariant");
346 if (is_full()) {
347 return NULL;
348 }
349 assert(block_size_request_words <= _reservation_size_request_words, "invariant");
350 if (expand_by(block_size_request_words, _reservation_size_request_words)) {
351 block = current()->commit(block_size_request_words);
352 assert(block != NULL, "The allocation was expected to succeed after the expansion");
353 }
354 return block;
355 }
356
357 JfrVirtualMemory::JfrVirtualMemory() :
358 _vmm(NULL),
359 _reserved_low(),
360 _reserved_high(),
361 _top(NULL),
362 _commit_point(NULL),
363 _physical_commit_size_request_words(0),
364 _aligned_datum_size_bytes(0) {}
365
366 JfrVirtualMemory::~JfrVirtualMemory() {
367 assert(_vmm != NULL, "invariant");
368 delete _vmm;
369 }
370
371 size_t JfrVirtualMemory::aligned_datum_size_bytes() const {
372 return _aligned_datum_size_bytes;
373 }
374
375 static void adjust_allocation_ratio(size_t* const reservation_size_bytes, size_t* const commit_size_bytes) {
376 assert(reservation_size_bytes != NULL, "invariant");
377 assert(*reservation_size_bytes > 0, "invariant");
378 assert(commit_size_bytes != NULL, "invariant");
379 assert(*commit_size_bytes > 0, "invariant");
380 assert(*reservation_size_bytes >= *commit_size_bytes, "invariant");
381 assert(is_aligned(*reservation_size_bytes, os::vm_allocation_granularity()), "invariant");
382 assert(is_aligned(*commit_size_bytes, os::vm_allocation_granularity()), "invariant");
383
384 size_t reservation_size_units = *reservation_size_bytes / os::vm_allocation_granularity();
385 size_t commit_size_units = *commit_size_bytes / os::vm_allocation_granularity();
386 assert(reservation_size_units > 0, "invariant");
387 assert(commit_size_units > 0, "invariant");
388
389 size_t original_ratio_units = reservation_size_units / commit_size_units;
390 size_t rem = reservation_size_units % commit_size_units;
391 assert(original_ratio_units > 0, "invariant");
392
393 if (rem > 0) {
394 reservation_size_units -= rem % original_ratio_units;
395 commit_size_units += rem / original_ratio_units;
396 }
397
398 assert(commit_size_units > 0, "invariant");
399 assert(reservation_size_units % original_ratio_units == 0, "invariant");
400 assert(original_ratio_units * commit_size_units == reservation_size_units , "invariant");
401 assert(original_ratio_units == reservation_size_units / commit_size_units, "invariant");
402 *reservation_size_bytes = reservation_size_units * os::vm_allocation_granularity();
403 *commit_size_bytes = commit_size_units * os::vm_allocation_granularity();
404 assert((*reservation_size_bytes % *commit_size_bytes) == 0, "invariant");
405 }
406
407
408 void* JfrVirtualMemory::initialize(size_t reservation_size_request_bytes,
409 size_t block_size_request_bytes,
410 size_t datum_size_bytes /* 1 */) {
411 assert(_vmm == NULL, "invariant");
412 _vmm = new JfrVirtualMemoryManager();
413
414 if (_vmm == NULL) {
415 return NULL;
416 }
417
418 assert(reservation_size_request_bytes > 0, "invariant");
419 _aligned_datum_size_bytes = align_up(datum_size_bytes, BytesPerWord);
420 assert(is_aligned(_aligned_datum_size_bytes, BytesPerWord), "invariant");
421
422 reservation_size_request_bytes = ReservedSpace::allocation_align_size_up(reservation_size_request_bytes);
423 assert(is_aligned(reservation_size_request_bytes, os::vm_allocation_granularity()), "invariant");
424 assert(is_aligned(reservation_size_request_bytes, _aligned_datum_size_bytes), "invariant");
425 block_size_request_bytes = MAX2(block_size_request_bytes, (size_t)os::vm_allocation_granularity());
426 block_size_request_bytes = ReservedSpace::allocation_align_size_up(block_size_request_bytes);
427 assert(is_aligned(block_size_request_bytes, os::vm_allocation_granularity()), "invariant");
428 assert(is_aligned(block_size_request_bytes, _aligned_datum_size_bytes), "invariant");
429 // adjustment to valid ratio in units of vm_allocation_granularity
430 adjust_allocation_ratio(&reservation_size_request_bytes, &block_size_request_bytes);
431 assert(is_aligned(reservation_size_request_bytes, os::vm_allocation_granularity()), "invariant");
432 assert(is_aligned(reservation_size_request_bytes, _aligned_datum_size_bytes), "invariant");
433 assert(is_aligned(block_size_request_bytes, os::vm_allocation_granularity()), "invariant");
434 assert(is_aligned(block_size_request_bytes, _aligned_datum_size_bytes), "invariant");
435 assert((reservation_size_request_bytes % block_size_request_bytes) == 0, "invariant");
436 const size_t reservation_size_request_words = reservation_size_request_bytes / BytesPerWord;
437 _physical_commit_size_request_words = block_size_request_bytes / BytesPerWord;
438 // virtual memory reservation
439 if (!_vmm->initialize(reservation_size_request_words)) {
440 // is implicitly "full" if reservation fails
441 assert(is_full(), "invariant");
442 return NULL;
443 }
444 _reserved_low = (const u1*)_vmm->reserved_low();
445 _reserved_high = (const u1*)_vmm->reserved_high();
446 // reservation complete
447 _top = (u1*)_vmm->committed_high();
448 _commit_point = _top;
449 assert(_reserved_low == _top, "invariant"); // initial empty state
450 assert((size_t)(_reserved_high - _reserved_low) == reservation_size_request_bytes, "invariant");
451 // initial commit
452 commit_memory_block();
453 return _top;
454 }
455
456 void* JfrVirtualMemory::commit(size_t block_size_request_words) {
457 assert(_vmm != NULL, "invariant");
458 assert(is_aligned(block_size_request_words * BytesPerWord, os::vm_allocation_granularity()), "invariant");
459 return _vmm->commit(block_size_request_words);
460 }
461
462 bool JfrVirtualMemory::is_full() const {
463 return _top == _reserved_high;
464 }
465
466 bool JfrVirtualMemory::is_empty() const {
467 return _top == _reserved_low;
468 }
469
470 bool JfrVirtualMemory::commit_memory_block() {
471 assert(_vmm != NULL, "invariant");
472 assert(!is_full(), "invariant");
473 assert(_top == _commit_point, "invariant");
474
475 void* const block = _vmm->commit(_physical_commit_size_request_words);
476 if (block != NULL) {
477 _commit_point = _vmm->committed_high();
478 return true;
479 }
480 // all reserved virtual memory is committed
481 assert(block == NULL, "invariant");
482 assert(_vmm->reserved_high() == _vmm->committed_high(), "invariant");
483 return false;
484 }
485
486 void* JfrVirtualMemory::new_datum() {
487 assert(_vmm != NULL, "invariant");
488 assert(!is_full(), "invariant");
489 if (_top == _commit_point) {
490 if (!commit_memory_block()) {
491 assert(is_full(), "invariant");
492 return NULL;
493 }
494 }
495 assert(_top + _aligned_datum_size_bytes <= _commit_point, "invariant");
496 u1* allocation = _top;
497 _top += _aligned_datum_size_bytes;
498 assert(is_aligned(allocation, _aligned_datum_size_bytes), "invariant");
499 return allocation;
500 }
501
502 void* JfrVirtualMemory::index_ptr(size_t index) {
503 assert((index * _aligned_datum_size_bytes) + _reserved_low < _commit_point, "invariant");
504 return (void*)((index * _aligned_datum_size_bytes) + _reserved_low);
505 }
506
507 void* JfrVirtualMemory::get(size_t index) {
508 return index_ptr(index);
509 }
510
511 size_t JfrVirtualMemory::count() const {
512 return (_top - _reserved_low) / _aligned_datum_size_bytes;
513 }
514
515 size_t JfrVirtualMemory::live_set() const {
516 return _top - _reserved_low;
517 }
518
519 size_t JfrVirtualMemory::reserved_size() const {
520 return _reserved_high - _reserved_low;
521 }
522
523 bool JfrVirtualMemory::compact(size_t index) {
524 assert(index > 0, "invariant");
525 assert(index <= reserved_size(), "invariant");
526 const u1* low = static_cast<u1*>(index_ptr(index));
527 const size_t block_size = _top - low;
528 memcpy(const_cast<u1*>(_reserved_low), low, block_size);
529 _top = const_cast<u1*>(_reserved_low) + block_size;
530 assert(live_set() == block_size, "invariant");
531 return true;
532 }