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/orderAccess.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 }