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 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 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 } 138 139 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 } 152 153 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 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); 212 213 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 }; 222 223 JfrVirtualMemoryManager::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) {} 230 231 JfrVirtualMemoryManager::~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 241 bool 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 } 249 250 bool 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. 255 bool 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 } 271 272 bool 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 } 282 283 void JfrVirtualMemoryManager::inc_reserved_words(size_t words) { 284 _current_reserved_words += words; 285 } 286 287 JfrVirtualMemorySegment* JfrVirtualMemoryManager::current() { 288 return _current_segment; 289 } 290 291 void JfrVirtualMemoryManager::inc_committed_words(size_t words) { 292 _current_committed_words += words; 293 } 294 295 bool 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 } 325 326 void 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 } 339 340 void* 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 } 357 358 JfrVirtualMemory::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) {} 366 367 JfrVirtualMemory::~JfrVirtualMemory() { 368 assert(_vmm != NULL, "invariant"); 369 delete _vmm; 370 } 371 372 size_t JfrVirtualMemory::aligned_datum_size_bytes() const { 373 return _aligned_datum_size_bytes; 374 } 375 376 static 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 } 407 408 409 void* 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 } 456 457 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 } 462 463 bool JfrVirtualMemory::is_full() const { 464 return _top == _reserved_high; 465 } 466 467 bool JfrVirtualMemory::is_empty() const { 468 return _top == _reserved_low; 469 } 470 471 bool 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 } 486 487 void* 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 } 502 503 void* 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 } 507 508 void* JfrVirtualMemory::get(size_t index) { 509 return index_ptr(index); 510 } 511 512 size_t JfrVirtualMemory::count() const { 513 return (_top - _reserved_low) / _aligned_datum_size_bytes; 514 } 515 516 size_t JfrVirtualMemory::live_set() const { 517 return _top - _reserved_low; 518 } 519 520 size_t JfrVirtualMemory::reserved_size() const { 521 return _reserved_high - _reserved_low; 522 } 523 524 bool 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 }