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