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
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
committed_low() const48 const u1* committed_low() const { return (const u1*)_virtual_memory.low(); }
committed_high() const49 const u1* committed_high() const { return (const u1*)_virtual_memory.high(); }
reserved_low() const50 const u1* reserved_low() const { return (const u1*)_virtual_memory.low_boundary(); }
reserved_high() const51 const u1* reserved_high() const { return (const u1*)_virtual_memory.high_boundary(); }
reserved_words() const52 size_t reserved_words() const { return _virtual_memory.reserved_size() / BytesPerWord; }
committed_words() const53 size_t committed_words() const { return _virtual_memory.actual_committed_size() / BytesPerWord; }
is_pre_committed() const54 bool is_pre_committed() const { return _virtual_memory.special(); }
virtual_space()55 VirtualSpace& virtual_space() { return _virtual_memory; }
56
57 JfrVirtualMemorySegment();
58 ~JfrVirtualMemorySegment();
59
next() const60 JfrVirtualMemorySegment* next() const { return _next; }
set_next(JfrVirtualMemorySegment * v)61 void set_next(JfrVirtualMemorySegment* v) { _next = v; }
62
63 // Returns true if requested size is available in the committed area
is_available(size_t block_size_request_words)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
top() const69 char* top() const { return _top; }
inc_top(size_t size_in_words)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
commit(size_t block_size_request_words)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
JfrVirtualMemorySegment()92 JfrVirtualMemorySegment::JfrVirtualMemorySegment() :
93 _next(NULL),
94 _top(NULL),
95 _rs(),
96 _virtual_memory() {}
97
~JfrVirtualMemorySegment()98 JfrVirtualMemorySegment::~JfrVirtualMemorySegment() {
99 decommit();
100 _rs.release();
101 }
102
initialize(size_t reservation_size_request_bytes)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 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
expand_by(size_t block_size_request_words)139 bool 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
decommit()153 void 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
take_from_committed(size_t block_size_request_words)166 void* 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
181 class 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
is_full() const213 bool is_full() const {
214 return reserved_high() == committed_high();
215 }
216
top() const217 u1* top() const { return reinterpret_cast<u1*>(_current_segment->top()); }
committed_low() const218 const u1* committed_low() const { return _current_segment->committed_low(); }
committed_high() const219 const u1* committed_high() const { return _current_segment->committed_high(); }
reserved_low() const220 const u1* reserved_low() const { return _current_segment->reserved_low(); }
reserved_high() const221 const u1* reserved_high() const { return _current_segment->reserved_high(); }
222 };
223
JfrVirtualMemoryManager()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
~JfrVirtualMemoryManager()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
initialize(size_t reservation_size_request_words,size_t segment_count)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
can_reserve() const251 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.
new_segment(size_t reservation_size_request_words)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
expand_segment_by(JfrVirtualMemorySegment * segment,size_t block_size_request_words)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
inc_reserved_words(size_t words)284 void JfrVirtualMemoryManager::inc_reserved_words(size_t words) {
285 _current_reserved_words += words;
286 }
287
current()288 JfrVirtualMemorySegment* JfrVirtualMemoryManager::current() {
289 return _current_segment;
290 }
291
inc_committed_words(size_t words)292 void JfrVirtualMemoryManager::inc_committed_words(size_t words) {
293 _current_committed_words += words;
294 }
295
expand_by(size_t block_size_request_words,size_t reservation_size_request_words)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
link(JfrVirtualMemorySegment * segment)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
commit(size_t block_size_request_words)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
JfrVirtualMemory()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
~JfrVirtualMemory()368 JfrVirtualMemory::~JfrVirtualMemory() {
369 assert(_vmm != NULL, "invariant");
370 delete _vmm;
371 }
372
aligned_datum_size_bytes() const373 size_t JfrVirtualMemory::aligned_datum_size_bytes() const {
374 return _aligned_datum_size_bytes;
375 }
376
adjust_allocation_ratio(size_t * const reservation_size_bytes,size_t * const commit_size_bytes)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
initialize(size_t reservation_size_request_bytes,size_t block_size_request_bytes,size_t datum_size_bytes)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 assert(static_cast<size_t>(_reserved_high - _reserved_low) == reservation_size_request_bytes, "invariant");
449 // reservation complete
450 _top = _vmm->top();
451 assert(_reserved_low == _top, "invariant"); // initial empty state
452 // initial commit
453 commit_memory_block();
454 return _top;
455 }
456
commit(size_t block_size_request_words)457 void* 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
is_full() const463 bool JfrVirtualMemory::is_full() const {
464 return _top == _reserved_high;
465 }
466
is_empty() const467 bool JfrVirtualMemory::is_empty() const {
468 return _top == _reserved_low;
469 }
470
commit_memory_block()471 bool JfrVirtualMemory::commit_memory_block() {
472 assert(_vmm != NULL, "invariant");
473 assert(!is_full(), "invariant");
474 void* const block = _vmm->commit(_physical_commit_size_request_words);
475 if (block != NULL) {
476 _commit_point = _vmm->committed_high();
477 return true;
478 }
479 // all reserved virtual memory is committed
480 assert(block == NULL, "invariant");
481 assert(_vmm->reserved_high() == _vmm->committed_high(), "invariant");
482 return false;
483 }
484
new_datum()485 void* JfrVirtualMemory::new_datum() {
486 assert(_vmm != NULL, "invariant");
487 assert(!is_full(), "invariant");
488 if (_top == _commit_point) {
489 if (!commit_memory_block()) {
490 assert(is_full(), "invariant");
491 return NULL;
492 }
493 }
494 assert(_top + _aligned_datum_size_bytes <= _commit_point, "invariant");
495 u1* allocation = _top;
496 _top += _aligned_datum_size_bytes;
497 assert(is_aligned(allocation, _aligned_datum_size_bytes), "invariant");
498 return allocation;
499 }
500
index_ptr(size_t index)501 void* JfrVirtualMemory::index_ptr(size_t index) {
502 assert((index * _aligned_datum_size_bytes) + _reserved_low < _commit_point, "invariant");
503 return (void*)((index * _aligned_datum_size_bytes) + _reserved_low);
504 }
505
get(size_t index)506 void* JfrVirtualMemory::get(size_t index) {
507 return index_ptr(index);
508 }
509
count() const510 size_t JfrVirtualMemory::count() const {
511 return (_top - _reserved_low) / _aligned_datum_size_bytes;
512 }
513
live_set() const514 size_t JfrVirtualMemory::live_set() const {
515 return _top - _reserved_low;
516 }
517
reserved_size() const518 size_t JfrVirtualMemory::reserved_size() const {
519 return _reserved_high - _reserved_low;
520 }
521
compact(size_t index)522 bool JfrVirtualMemory::compact(size_t index) {
523 assert(index > 0, "invariant");
524 assert(index <= reserved_size(), "invariant");
525 const u1* low = static_cast<u1*>(index_ptr(index));
526 const size_t block_size = _top - low;
527 memcpy(const_cast<u1*>(_reserved_low), low, block_size);
528 _top = const_cast<u1*>(_reserved_low) + block_size;
529 assert(live_set() == block_size, "invariant");
530 return true;
531 }
532