1 /* 2 * Copyright (c) 2001, 2015, 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 "gc/g1/concurrentG1Refine.hpp" 27 #include "gc/g1/g1BlockOffsetTable.inline.hpp" 28 #include "gc/g1/g1CollectedHeap.inline.hpp" 29 #include "gc/g1/heapRegionManager.inline.hpp" 30 #include "gc/g1/heapRegionRemSet.hpp" 31 #include "gc/shared/space.inline.hpp" 32 #include "memory/allocation.hpp" 33 #include "memory/padded.inline.hpp" 34 #include "oops/oop.inline.hpp" 35 #include "runtime/atomic.inline.hpp" 36 #include "utilities/bitMap.inline.hpp" 37 #include "utilities/globalDefinitions.hpp" 38 #include "utilities/growableArray.hpp" 39 40 class PerRegionTable: public CHeapObj<mtGC> { 41 friend class OtherRegionsTable; 42 friend class HeapRegionRemSetIterator; 43 44 HeapRegion* _hr; 45 BitMap _bm; 46 jint _occupied; 47 48 // next pointer for free/allocated 'all' list 49 PerRegionTable* _next; 50 51 // prev pointer for the allocated 'all' list 52 PerRegionTable* _prev; 53 54 // next pointer in collision list 55 PerRegionTable * _collision_list_next; 56 57 // Global free list of PRTs 58 static PerRegionTable* _free_list; 59 60 protected: 61 // We need access in order to union things into the base table. 62 BitMap* bm() { return &_bm; } 63 64 void recount_occupied() { 65 _occupied = (jint) bm()->count_one_bits(); 66 } 67 68 PerRegionTable(HeapRegion* hr) : 69 _hr(hr), 70 _occupied(0), 71 _bm(HeapRegion::CardsPerRegion, false /* in-resource-area */), 72 _collision_list_next(NULL), _next(NULL), _prev(NULL) 73 {} 74 75 void add_card_work(CardIdx_t from_card, bool par) { 76 if (!_bm.at(from_card)) { 77 if (par) { 78 if (_bm.par_at_put(from_card, 1)) { 79 Atomic::inc(&_occupied); 80 } 81 } else { 82 _bm.at_put(from_card, 1); 83 _occupied++; 84 } 85 } 86 } 87 88 void add_reference_work(OopOrNarrowOopStar from, bool par) { 89 // Must make this robust in case "from" is not in "_hr", because of 90 // concurrency. 91 92 if (G1TraceHeapRegionRememberedSet) { 93 gclog_or_tty->print_cr(" PRT::Add_reference_work(" PTR_FORMAT "->" PTR_FORMAT ").", 94 p2i(from), 95 UseCompressedOops 96 ? p2i(oopDesc::load_decode_heap_oop((narrowOop*)from)) 97 : p2i(oopDesc::load_decode_heap_oop((oop*)from))); 98 } 99 100 HeapRegion* loc_hr = hr(); 101 // If the test below fails, then this table was reused concurrently 102 // with this operation. This is OK, since the old table was coarsened, 103 // and adding a bit to the new table is never incorrect. 104 // If the table used to belong to a continues humongous region and is 105 // now reused for the corresponding start humongous region, we need to 106 // make sure that we detect this. Thus, we call is_in_reserved_raw() 107 // instead of just is_in_reserved() here. 108 if (loc_hr->is_in_reserved_raw(from)) { 109 size_t hw_offset = pointer_delta((HeapWord*)from, loc_hr->bottom()); 110 CardIdx_t from_card = (CardIdx_t) 111 hw_offset >> (CardTableModRefBS::card_shift - LogHeapWordSize); 112 113 assert(0 <= from_card && (size_t)from_card < HeapRegion::CardsPerRegion, 114 "Must be in range."); 115 add_card_work(from_card, par); 116 } 117 } 118 119 public: 120 121 HeapRegion* hr() const { return _hr; } 122 123 jint occupied() const { 124 // Overkill, but if we ever need it... 125 // guarantee(_occupied == _bm.count_one_bits(), "Check"); 126 return _occupied; 127 } 128 129 void init(HeapRegion* hr, bool clear_links_to_all_list) { 130 if (clear_links_to_all_list) { 131 set_next(NULL); 132 set_prev(NULL); 133 } 134 _hr = hr; 135 _collision_list_next = NULL; 136 _occupied = 0; 137 _bm.clear(); 138 } 139 140 void add_reference(OopOrNarrowOopStar from) { 141 add_reference_work(from, /*parallel*/ true); 142 } 143 144 void seq_add_reference(OopOrNarrowOopStar from) { 145 add_reference_work(from, /*parallel*/ false); 146 } 147 148 void scrub(CardTableModRefBS* ctbs, BitMap* card_bm) { 149 HeapWord* hr_bot = hr()->bottom(); 150 size_t hr_first_card_index = ctbs->index_for(hr_bot); 151 bm()->set_intersection_at_offset(*card_bm, hr_first_card_index); 152 recount_occupied(); 153 } 154 155 void add_card(CardIdx_t from_card_index) { 156 add_card_work(from_card_index, /*parallel*/ true); 157 } 158 159 void seq_add_card(CardIdx_t from_card_index) { 160 add_card_work(from_card_index, /*parallel*/ false); 161 } 162 163 // (Destructively) union the bitmap of the current table into the given 164 // bitmap (which is assumed to be of the same size.) 165 void union_bitmap_into(BitMap* bm) { 166 bm->set_union(_bm); 167 } 168 169 // Mem size in bytes. 170 size_t mem_size() const { 171 return sizeof(PerRegionTable) + _bm.size_in_words() * HeapWordSize; 172 } 173 174 // Requires "from" to be in "hr()". 175 bool contains_reference(OopOrNarrowOopStar from) const { 176 assert(hr()->is_in_reserved(from), "Precondition."); 177 size_t card_ind = pointer_delta(from, hr()->bottom(), 178 CardTableModRefBS::card_size); 179 return _bm.at(card_ind); 180 } 181 182 // Bulk-free the PRTs from prt to last, assumes that they are 183 // linked together using their _next field. 184 static void bulk_free(PerRegionTable* prt, PerRegionTable* last) { 185 while (true) { 186 PerRegionTable* fl = _free_list; 187 last->set_next(fl); 188 PerRegionTable* res = (PerRegionTable*) Atomic::cmpxchg_ptr(prt, &_free_list, fl); 189 if (res == fl) { 190 return; 191 } 192 } 193 ShouldNotReachHere(); 194 } 195 196 static void free(PerRegionTable* prt) { 197 bulk_free(prt, prt); 198 } 199 200 // Returns an initialized PerRegionTable instance. 201 static PerRegionTable* alloc(HeapRegion* hr) { 202 PerRegionTable* fl = _free_list; 203 while (fl != NULL) { 204 PerRegionTable* nxt = fl->next(); 205 PerRegionTable* res = 206 (PerRegionTable*) 207 Atomic::cmpxchg_ptr(nxt, &_free_list, fl); 208 if (res == fl) { 209 fl->init(hr, true); 210 return fl; 211 } else { 212 fl = _free_list; 213 } 214 } 215 assert(fl == NULL, "Loop condition."); 216 return new PerRegionTable(hr); 217 } 218 219 PerRegionTable* next() const { return _next; } 220 void set_next(PerRegionTable* next) { _next = next; } 221 PerRegionTable* prev() const { return _prev; } 222 void set_prev(PerRegionTable* prev) { _prev = prev; } 223 224 // Accessor and Modification routines for the pointer for the 225 // singly linked collision list that links the PRTs within the 226 // OtherRegionsTable::_fine_grain_regions hash table. 227 // 228 // It might be useful to also make the collision list doubly linked 229 // to avoid iteration over the collisions list during scrubbing/deletion. 230 // OTOH there might not be many collisions. 231 232 PerRegionTable* collision_list_next() const { 233 return _collision_list_next; 234 } 235 236 void set_collision_list_next(PerRegionTable* next) { 237 _collision_list_next = next; 238 } 239 240 PerRegionTable** collision_list_next_addr() { 241 return &_collision_list_next; 242 } 243 244 static size_t fl_mem_size() { 245 PerRegionTable* cur = _free_list; 246 size_t res = 0; 247 while (cur != NULL) { 248 res += cur->mem_size(); 249 cur = cur->next(); 250 } 251 return res; 252 } 253 254 static void test_fl_mem_size(); 255 }; 256 257 PerRegionTable* PerRegionTable::_free_list = NULL; 258 259 size_t OtherRegionsTable::_max_fine_entries = 0; 260 size_t OtherRegionsTable::_mod_max_fine_entries_mask = 0; 261 size_t OtherRegionsTable::_fine_eviction_stride = 0; 262 size_t OtherRegionsTable::_fine_eviction_sample_size = 0; 263 264 OtherRegionsTable::OtherRegionsTable(HeapRegion* hr, Mutex* m) : 265 _g1h(G1CollectedHeap::heap()), 266 _hr(hr), _m(m), 267 _coarse_map(G1CollectedHeap::heap()->max_regions(), 268 false /* in-resource-area */), 269 _fine_grain_regions(NULL), 270 _first_all_fine_prts(NULL), _last_all_fine_prts(NULL), 271 _n_fine_entries(0), _n_coarse_entries(0), 272 _fine_eviction_start(0), 273 _sparse_table(hr) 274 { 275 typedef PerRegionTable* PerRegionTablePtr; 276 277 if (_max_fine_entries == 0) { 278 assert(_mod_max_fine_entries_mask == 0, "Both or none."); 279 size_t max_entries_log = (size_t)log2_long((jlong)G1RSetRegionEntries); 280 _max_fine_entries = (size_t)1 << max_entries_log; 281 _mod_max_fine_entries_mask = _max_fine_entries - 1; 282 283 assert(_fine_eviction_sample_size == 0 284 && _fine_eviction_stride == 0, "All init at same time."); 285 _fine_eviction_sample_size = MAX2((size_t)4, max_entries_log); 286 _fine_eviction_stride = _max_fine_entries / _fine_eviction_sample_size; 287 } 288 289 _fine_grain_regions = NEW_C_HEAP_ARRAY3(PerRegionTablePtr, _max_fine_entries, 290 mtGC, CURRENT_PC, AllocFailStrategy::RETURN_NULL); 291 292 if (_fine_grain_regions == NULL) { 293 vm_exit_out_of_memory(sizeof(void*)*_max_fine_entries, OOM_MALLOC_ERROR, 294 "Failed to allocate _fine_grain_entries."); 295 } 296 297 for (size_t i = 0; i < _max_fine_entries; i++) { 298 _fine_grain_regions[i] = NULL; 299 } 300 } 301 302 void OtherRegionsTable::link_to_all(PerRegionTable* prt) { 303 // We always append to the beginning of the list for convenience; 304 // the order of entries in this list does not matter. 305 if (_first_all_fine_prts != NULL) { 306 assert(_first_all_fine_prts->prev() == NULL, "invariant"); 307 _first_all_fine_prts->set_prev(prt); 308 prt->set_next(_first_all_fine_prts); 309 } else { 310 // this is the first element we insert. Adjust the "last" pointer 311 _last_all_fine_prts = prt; 312 assert(prt->next() == NULL, "just checking"); 313 } 314 // the new element is always the first element without a predecessor 315 prt->set_prev(NULL); 316 _first_all_fine_prts = prt; 317 318 assert(prt->prev() == NULL, "just checking"); 319 assert(_first_all_fine_prts == prt, "just checking"); 320 assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) || 321 (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL), 322 "just checking"); 323 assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL, 324 "just checking"); 325 assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL, 326 "just checking"); 327 } 328 329 void OtherRegionsTable::unlink_from_all(PerRegionTable* prt) { 330 if (prt->prev() != NULL) { 331 assert(_first_all_fine_prts != prt, "just checking"); 332 prt->prev()->set_next(prt->next()); 333 // removing the last element in the list? 334 if (_last_all_fine_prts == prt) { 335 _last_all_fine_prts = prt->prev(); 336 } 337 } else { 338 assert(_first_all_fine_prts == prt, "just checking"); 339 _first_all_fine_prts = prt->next(); 340 // list is empty now? 341 if (_first_all_fine_prts == NULL) { 342 _last_all_fine_prts = NULL; 343 } 344 } 345 346 if (prt->next() != NULL) { 347 prt->next()->set_prev(prt->prev()); 348 } 349 350 prt->set_next(NULL); 351 prt->set_prev(NULL); 352 353 assert((_first_all_fine_prts == NULL && _last_all_fine_prts == NULL) || 354 (_first_all_fine_prts != NULL && _last_all_fine_prts != NULL), 355 "just checking"); 356 assert(_last_all_fine_prts == NULL || _last_all_fine_prts->next() == NULL, 357 "just checking"); 358 assert(_first_all_fine_prts == NULL || _first_all_fine_prts->prev() == NULL, 359 "just checking"); 360 } 361 362 int** FromCardCache::_cache = NULL; 363 uint FromCardCache::_max_regions = 0; 364 size_t FromCardCache::_static_mem_size = 0; 365 366 void FromCardCache::initialize(uint n_par_rs, uint max_num_regions) { 367 guarantee(_cache == NULL, "Should not call this multiple times"); 368 369 _max_regions = max_num_regions; 370 _cache = Padded2DArray<int, mtGC>::create_unfreeable(n_par_rs, 371 _max_regions, 372 &_static_mem_size); 373 374 invalidate(0, _max_regions); 375 } 376 377 void FromCardCache::invalidate(uint start_idx, size_t new_num_regions) { 378 guarantee((size_t)start_idx + new_num_regions <= max_uintx, 379 err_msg("Trying to invalidate beyond maximum region, from %u size " SIZE_FORMAT, 380 start_idx, new_num_regions)); 381 for (uint i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) { 382 uint end_idx = (start_idx + (uint)new_num_regions); 383 assert(end_idx <= _max_regions, "Must be within max."); 384 for (uint j = start_idx; j < end_idx; j++) { 385 set(i, j, InvalidCard); 386 } 387 } 388 } 389 390 #ifndef PRODUCT 391 void FromCardCache::print(outputStream* out) { 392 for (uint i = 0; i < HeapRegionRemSet::num_par_rem_sets(); i++) { 393 for (uint j = 0; j < _max_regions; j++) { 394 out->print_cr("_from_card_cache[%u][%u] = %d.", 395 i, j, at(i, j)); 396 } 397 } 398 } 399 #endif 400 401 void FromCardCache::clear(uint region_idx) { 402 uint num_par_remsets = HeapRegionRemSet::num_par_rem_sets(); 403 for (uint i = 0; i < num_par_remsets; i++) { 404 set(i, region_idx, InvalidCard); 405 } 406 } 407 408 void OtherRegionsTable::add_reference(OopOrNarrowOopStar from, uint tid) { 409 uint cur_hrm_ind = _hr->hrm_index(); 410 411 if (G1TraceHeapRegionRememberedSet) { 412 gclog_or_tty->print_cr("ORT::add_reference_work(" PTR_FORMAT "->" PTR_FORMAT ").", 413 p2i(from), 414 UseCompressedOops 415 ? p2i(oopDesc::load_decode_heap_oop((narrowOop*)from)) 416 : p2i(oopDesc::load_decode_heap_oop((oop*)from))); 417 } 418 419 int from_card = (int)(uintptr_t(from) >> CardTableModRefBS::card_shift); 420 421 if (G1TraceHeapRegionRememberedSet) { 422 gclog_or_tty->print_cr("Table for [" PTR_FORMAT "...): card %d (cache = %d)", 423 p2i(_hr->bottom()), from_card, 424 FromCardCache::at(tid, cur_hrm_ind)); 425 } 426 427 if (FromCardCache::contains_or_replace(tid, cur_hrm_ind, from_card)) { 428 if (G1TraceHeapRegionRememberedSet) { 429 gclog_or_tty->print_cr(" from-card cache hit."); 430 } 431 assert(contains_reference(from), "We just added it!"); 432 return; 433 } 434 435 // Note that this may be a continued H region. 436 HeapRegion* from_hr = _g1h->heap_region_containing_raw(from); 437 RegionIdx_t from_hrm_ind = (RegionIdx_t) from_hr->hrm_index(); 438 439 // If the region is already coarsened, return. 440 if (_coarse_map.at(from_hrm_ind)) { 441 if (G1TraceHeapRegionRememberedSet) { 442 gclog_or_tty->print_cr(" coarse map hit."); 443 } 444 assert(contains_reference(from), "We just added it!"); 445 return; 446 } 447 448 // Otherwise find a per-region table to add it to. 449 size_t ind = from_hrm_ind & _mod_max_fine_entries_mask; 450 PerRegionTable* prt = find_region_table(ind, from_hr); 451 if (prt == NULL) { 452 MutexLockerEx x(_m, Mutex::_no_safepoint_check_flag); 453 // Confirm that it's really not there... 454 prt = find_region_table(ind, from_hr); 455 if (prt == NULL) { 456 457 uintptr_t from_hr_bot_card_index = 458 uintptr_t(from_hr->bottom()) 459 >> CardTableModRefBS::card_shift; 460 CardIdx_t card_index = from_card - from_hr_bot_card_index; 461 assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion, 462 "Must be in range."); 463 if (G1HRRSUseSparseTable && 464 _sparse_table.add_card(from_hrm_ind, card_index)) { 465 if (G1RecordHRRSOops) { 466 HeapRegionRemSet::record(_hr, from); 467 if (G1TraceHeapRegionRememberedSet) { 468 gclog_or_tty->print(" Added card " PTR_FORMAT " to region " 469 "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n", 470 align_size_down(uintptr_t(from), 471 CardTableModRefBS::card_size), 472 p2i(_hr->bottom()), p2i(from)); 473 } 474 } 475 if (G1TraceHeapRegionRememberedSet) { 476 gclog_or_tty->print_cr(" added card to sparse table."); 477 } 478 assert(contains_reference_locked(from), "We just added it!"); 479 return; 480 } else { 481 if (G1TraceHeapRegionRememberedSet) { 482 gclog_or_tty->print_cr(" [tid %u] sparse table entry " 483 "overflow(f: %d, t: %u)", 484 tid, from_hrm_ind, cur_hrm_ind); 485 } 486 } 487 488 if (_n_fine_entries == _max_fine_entries) { 489 prt = delete_region_table(); 490 // There is no need to clear the links to the 'all' list here: 491 // prt will be reused immediately, i.e. remain in the 'all' list. 492 prt->init(from_hr, false /* clear_links_to_all_list */); 493 } else { 494 prt = PerRegionTable::alloc(from_hr); 495 link_to_all(prt); 496 } 497 498 PerRegionTable* first_prt = _fine_grain_regions[ind]; 499 prt->set_collision_list_next(first_prt); 500 // The assignment into _fine_grain_regions allows the prt to 501 // start being used concurrently. In addition to 502 // collision_list_next which must be visible (else concurrent 503 // parsing of the list, if any, may fail to see other entries), 504 // the content of the prt must be visible (else for instance 505 // some mark bits may not yet seem cleared or a 'later' update 506 // performed by a concurrent thread could be undone when the 507 // zeroing becomes visible). This requires store ordering. 508 OrderAccess::release_store_ptr((volatile PerRegionTable*)&_fine_grain_regions[ind], prt); 509 _n_fine_entries++; 510 511 if (G1HRRSUseSparseTable) { 512 // Transfer from sparse to fine-grain. 513 SparsePRTEntry *sprt_entry = _sparse_table.get_entry(from_hrm_ind); 514 assert(sprt_entry != NULL, "There should have been an entry"); 515 for (int i = 0; i < SparsePRTEntry::cards_num(); i++) { 516 CardIdx_t c = sprt_entry->card(i); 517 if (c != SparsePRTEntry::NullEntry) { 518 prt->add_card(c); 519 } 520 } 521 // Now we can delete the sparse entry. 522 bool res = _sparse_table.delete_entry(from_hrm_ind); 523 assert(res, "It should have been there."); 524 } 525 } 526 assert(prt != NULL && prt->hr() == from_hr, "consequence"); 527 } 528 // Note that we can't assert "prt->hr() == from_hr", because of the 529 // possibility of concurrent reuse. But see head comment of 530 // OtherRegionsTable for why this is OK. 531 assert(prt != NULL, "Inv"); 532 533 prt->add_reference(from); 534 535 if (G1RecordHRRSOops) { 536 HeapRegionRemSet::record(_hr, from); 537 if (G1TraceHeapRegionRememberedSet) { 538 gclog_or_tty->print("Added card " PTR_FORMAT " to region " 539 "[" PTR_FORMAT "...) for ref " PTR_FORMAT ".\n", 540 align_size_down(uintptr_t(from), 541 CardTableModRefBS::card_size), 542 p2i(_hr->bottom()), p2i(from)); 543 } 544 } 545 assert(contains_reference(from), "We just added it!"); 546 } 547 548 PerRegionTable* 549 OtherRegionsTable::find_region_table(size_t ind, HeapRegion* hr) const { 550 assert(ind < _max_fine_entries, "Preconditions."); 551 PerRegionTable* prt = _fine_grain_regions[ind]; 552 while (prt != NULL && prt->hr() != hr) { 553 prt = prt->collision_list_next(); 554 } 555 // Loop postcondition is the method postcondition. 556 return prt; 557 } 558 559 jint OtherRegionsTable::_n_coarsenings = 0; 560 561 PerRegionTable* OtherRegionsTable::delete_region_table() { 562 assert(_m->owned_by_self(), "Precondition"); 563 assert(_n_fine_entries == _max_fine_entries, "Precondition"); 564 PerRegionTable* max = NULL; 565 jint max_occ = 0; 566 PerRegionTable** max_prev; 567 size_t max_ind; 568 569 size_t i = _fine_eviction_start; 570 for (size_t k = 0; k < _fine_eviction_sample_size; k++) { 571 size_t ii = i; 572 // Make sure we get a non-NULL sample. 573 while (_fine_grain_regions[ii] == NULL) { 574 ii++; 575 if (ii == _max_fine_entries) ii = 0; 576 guarantee(ii != i, "We must find one."); 577 } 578 PerRegionTable** prev = &_fine_grain_regions[ii]; 579 PerRegionTable* cur = *prev; 580 while (cur != NULL) { 581 jint cur_occ = cur->occupied(); 582 if (max == NULL || cur_occ > max_occ) { 583 max = cur; 584 max_prev = prev; 585 max_ind = i; 586 max_occ = cur_occ; 587 } 588 prev = cur->collision_list_next_addr(); 589 cur = cur->collision_list_next(); 590 } 591 i = i + _fine_eviction_stride; 592 if (i >= _n_fine_entries) i = i - _n_fine_entries; 593 } 594 595 _fine_eviction_start++; 596 597 if (_fine_eviction_start >= _n_fine_entries) { 598 _fine_eviction_start -= _n_fine_entries; 599 } 600 601 guarantee(max != NULL, "Since _n_fine_entries > 0"); 602 603 // Set the corresponding coarse bit. 604 size_t max_hrm_index = (size_t) max->hr()->hrm_index(); 605 if (!_coarse_map.at(max_hrm_index)) { 606 _coarse_map.at_put(max_hrm_index, true); 607 _n_coarse_entries++; 608 if (G1TraceHeapRegionRememberedSet) { 609 gclog_or_tty->print("Coarsened entry in region [" PTR_FORMAT "...] " 610 "for region [" PTR_FORMAT "...] (" SIZE_FORMAT " coarse entries).\n", 611 p2i(_hr->bottom()), 612 p2i(max->hr()->bottom()), 613 _n_coarse_entries); 614 } 615 } 616 617 // Unsplice. 618 *max_prev = max->collision_list_next(); 619 Atomic::inc(&_n_coarsenings); 620 _n_fine_entries--; 621 return max; 622 } 623 624 void OtherRegionsTable::scrub(CardTableModRefBS* ctbs, 625 BitMap* region_bm, BitMap* card_bm) { 626 // First eliminated garbage regions from the coarse map. 627 if (G1RSScrubVerbose) { 628 gclog_or_tty->print_cr("Scrubbing region %u:", _hr->hrm_index()); 629 } 630 631 assert(_coarse_map.size() == region_bm->size(), "Precondition"); 632 if (G1RSScrubVerbose) { 633 gclog_or_tty->print(" Coarse map: before = " SIZE_FORMAT "...", 634 _n_coarse_entries); 635 } 636 _coarse_map.set_intersection(*region_bm); 637 _n_coarse_entries = _coarse_map.count_one_bits(); 638 if (G1RSScrubVerbose) { 639 gclog_or_tty->print_cr(" after = " SIZE_FORMAT ".", _n_coarse_entries); 640 } 641 642 // Now do the fine-grained maps. 643 for (size_t i = 0; i < _max_fine_entries; i++) { 644 PerRegionTable* cur = _fine_grain_regions[i]; 645 PerRegionTable** prev = &_fine_grain_regions[i]; 646 while (cur != NULL) { 647 PerRegionTable* nxt = cur->collision_list_next(); 648 // If the entire region is dead, eliminate. 649 if (G1RSScrubVerbose) { 650 gclog_or_tty->print_cr(" For other region %u:", 651 cur->hr()->hrm_index()); 652 } 653 if (!region_bm->at((size_t) cur->hr()->hrm_index())) { 654 *prev = nxt; 655 cur->set_collision_list_next(NULL); 656 _n_fine_entries--; 657 if (G1RSScrubVerbose) { 658 gclog_or_tty->print_cr(" deleted via region map."); 659 } 660 unlink_from_all(cur); 661 PerRegionTable::free(cur); 662 } else { 663 // Do fine-grain elimination. 664 if (G1RSScrubVerbose) { 665 gclog_or_tty->print(" occ: before = %4d.", cur->occupied()); 666 } 667 cur->scrub(ctbs, card_bm); 668 if (G1RSScrubVerbose) { 669 gclog_or_tty->print_cr(" after = %4d.", cur->occupied()); 670 } 671 // Did that empty the table completely? 672 if (cur->occupied() == 0) { 673 *prev = nxt; 674 cur->set_collision_list_next(NULL); 675 _n_fine_entries--; 676 unlink_from_all(cur); 677 PerRegionTable::free(cur); 678 } else { 679 prev = cur->collision_list_next_addr(); 680 } 681 } 682 cur = nxt; 683 } 684 } 685 // Since we may have deleted a from_card_cache entry from the RS, clear 686 // the FCC. 687 clear_fcc(); 688 } 689 690 bool OtherRegionsTable::occupancy_less_or_equal_than(size_t limit) const { 691 if (limit <= (size_t)G1RSetSparseRegionEntries) { 692 return occ_coarse() == 0 && _first_all_fine_prts == NULL && occ_sparse() <= limit; 693 } else { 694 // Current uses of this method may only use values less than G1RSetSparseRegionEntries 695 // for the limit. The solution, comparing against occupied() would be too slow 696 // at this time. 697 Unimplemented(); 698 return false; 699 } 700 } 701 702 bool OtherRegionsTable::is_empty() const { 703 return occ_sparse() == 0 && occ_coarse() == 0 && _first_all_fine_prts == NULL; 704 } 705 706 size_t OtherRegionsTable::occupied() const { 707 size_t sum = occ_fine(); 708 sum += occ_sparse(); 709 sum += occ_coarse(); 710 return sum; 711 } 712 713 size_t OtherRegionsTable::occ_fine() const { 714 size_t sum = 0; 715 716 size_t num = 0; 717 PerRegionTable * cur = _first_all_fine_prts; 718 while (cur != NULL) { 719 sum += cur->occupied(); 720 cur = cur->next(); 721 num++; 722 } 723 guarantee(num == _n_fine_entries, "just checking"); 724 return sum; 725 } 726 727 size_t OtherRegionsTable::occ_coarse() const { 728 return (_n_coarse_entries * HeapRegion::CardsPerRegion); 729 } 730 731 size_t OtherRegionsTable::occ_sparse() const { 732 return _sparse_table.occupied(); 733 } 734 735 size_t OtherRegionsTable::mem_size() const { 736 size_t sum = 0; 737 // all PRTs are of the same size so it is sufficient to query only one of them. 738 if (_first_all_fine_prts != NULL) { 739 assert(_last_all_fine_prts != NULL && 740 _first_all_fine_prts->mem_size() == _last_all_fine_prts->mem_size(), "check that mem_size() is constant"); 741 sum += _first_all_fine_prts->mem_size() * _n_fine_entries; 742 } 743 sum += (sizeof(PerRegionTable*) * _max_fine_entries); 744 sum += (_coarse_map.size_in_words() * HeapWordSize); 745 sum += (_sparse_table.mem_size()); 746 sum += sizeof(OtherRegionsTable) - sizeof(_sparse_table); // Avoid double counting above. 747 return sum; 748 } 749 750 size_t OtherRegionsTable::static_mem_size() { 751 return FromCardCache::static_mem_size(); 752 } 753 754 size_t OtherRegionsTable::fl_mem_size() { 755 return PerRegionTable::fl_mem_size(); 756 } 757 758 void OtherRegionsTable::clear_fcc() { 759 FromCardCache::clear(_hr->hrm_index()); 760 } 761 762 void OtherRegionsTable::clear() { 763 // if there are no entries, skip this step 764 if (_first_all_fine_prts != NULL) { 765 guarantee(_first_all_fine_prts != NULL && _last_all_fine_prts != NULL, "just checking"); 766 PerRegionTable::bulk_free(_first_all_fine_prts, _last_all_fine_prts); 767 memset(_fine_grain_regions, 0, _max_fine_entries * sizeof(_fine_grain_regions[0])); 768 } else { 769 guarantee(_first_all_fine_prts == NULL && _last_all_fine_prts == NULL, "just checking"); 770 } 771 772 _first_all_fine_prts = _last_all_fine_prts = NULL; 773 _sparse_table.clear(); 774 _coarse_map.clear(); 775 _n_fine_entries = 0; 776 _n_coarse_entries = 0; 777 778 clear_fcc(); 779 } 780 781 bool OtherRegionsTable::contains_reference(OopOrNarrowOopStar from) const { 782 // Cast away const in this case. 783 MutexLockerEx x((Mutex*)_m, Mutex::_no_safepoint_check_flag); 784 return contains_reference_locked(from); 785 } 786 787 bool OtherRegionsTable::contains_reference_locked(OopOrNarrowOopStar from) const { 788 HeapRegion* hr = _g1h->heap_region_containing_raw(from); 789 RegionIdx_t hr_ind = (RegionIdx_t) hr->hrm_index(); 790 // Is this region in the coarse map? 791 if (_coarse_map.at(hr_ind)) return true; 792 793 PerRegionTable* prt = find_region_table(hr_ind & _mod_max_fine_entries_mask, 794 hr); 795 if (prt != NULL) { 796 return prt->contains_reference(from); 797 798 } else { 799 uintptr_t from_card = 800 (uintptr_t(from) >> CardTableModRefBS::card_shift); 801 uintptr_t hr_bot_card_index = 802 uintptr_t(hr->bottom()) >> CardTableModRefBS::card_shift; 803 assert(from_card >= hr_bot_card_index, "Inv"); 804 CardIdx_t card_index = from_card - hr_bot_card_index; 805 assert(0 <= card_index && (size_t)card_index < HeapRegion::CardsPerRegion, 806 "Must be in range."); 807 return _sparse_table.contains_card(hr_ind, card_index); 808 } 809 } 810 811 void 812 OtherRegionsTable::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) { 813 _sparse_table.do_cleanup_work(hrrs_cleanup_task); 814 } 815 816 // Determines how many threads can add records to an rset in parallel. 817 // This can be done by either mutator threads together with the 818 // concurrent refinement threads or GC threads. 819 uint HeapRegionRemSet::num_par_rem_sets() { 820 return MAX2(DirtyCardQueueSet::num_par_ids() + ConcurrentG1Refine::thread_num(), (uint)ParallelGCThreads); 821 } 822 823 HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa, 824 HeapRegion* hr) 825 : _bosa(bosa), 826 _m(Mutex::leaf, FormatBuffer<128>("HeapRegionRemSet lock #%u", hr->hrm_index()), true, Monitor::_safepoint_check_never), 827 _code_roots(), _other_regions(hr, &_m), _iter_state(Unclaimed), _iter_claimed(0) { 828 reset_for_par_iteration(); 829 } 830 831 void HeapRegionRemSet::setup_remset_size() { 832 // Setup sparse and fine-grain tables sizes. 833 // table_size = base * (log(region_size / 1M) + 1) 834 const int LOG_M = 20; 835 int region_size_log_mb = MAX2(HeapRegion::LogOfHRGrainBytes - LOG_M, 0); 836 if (FLAG_IS_DEFAULT(G1RSetSparseRegionEntries)) { 837 G1RSetSparseRegionEntries = G1RSetSparseRegionEntriesBase * (region_size_log_mb + 1); 838 } 839 if (FLAG_IS_DEFAULT(G1RSetRegionEntries)) { 840 G1RSetRegionEntries = G1RSetRegionEntriesBase * (region_size_log_mb + 1); 841 } 842 guarantee(G1RSetSparseRegionEntries > 0 && G1RSetRegionEntries > 0 , "Sanity"); 843 } 844 845 bool HeapRegionRemSet::claim_iter() { 846 if (_iter_state != Unclaimed) return false; 847 jint res = Atomic::cmpxchg(Claimed, (jint*)(&_iter_state), Unclaimed); 848 return (res == Unclaimed); 849 } 850 851 void HeapRegionRemSet::set_iter_complete() { 852 _iter_state = Complete; 853 } 854 855 bool HeapRegionRemSet::iter_is_complete() { 856 return _iter_state == Complete; 857 } 858 859 #ifndef PRODUCT 860 void HeapRegionRemSet::print() { 861 HeapRegionRemSetIterator iter(this); 862 size_t card_index; 863 while (iter.has_next(card_index)) { 864 HeapWord* card_start = 865 G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index); 866 gclog_or_tty->print_cr(" Card " PTR_FORMAT, p2i(card_start)); 867 } 868 if (iter.n_yielded() != occupied()) { 869 gclog_or_tty->print_cr("Yielded disagrees with occupied:"); 870 gclog_or_tty->print_cr(" " SIZE_FORMAT_W(6) " yielded (" SIZE_FORMAT_W(6) 871 " coarse, " SIZE_FORMAT_W(6) " fine).", 872 iter.n_yielded(), 873 iter.n_yielded_coarse(), iter.n_yielded_fine()); 874 gclog_or_tty->print_cr(" " SIZE_FORMAT_W(6) " occ (" SIZE_FORMAT_W(6) 875 " coarse, " SIZE_FORMAT_W(6) " fine).", 876 occupied(), occ_coarse(), occ_fine()); 877 } 878 guarantee(iter.n_yielded() == occupied(), 879 "We should have yielded all the represented cards."); 880 } 881 #endif 882 883 void HeapRegionRemSet::cleanup() { 884 SparsePRT::cleanup_all(); 885 } 886 887 void HeapRegionRemSet::clear() { 888 MutexLockerEx x(&_m, Mutex::_no_safepoint_check_flag); 889 clear_locked(); 890 } 891 892 void HeapRegionRemSet::clear_locked() { 893 _code_roots.clear(); 894 _other_regions.clear(); 895 assert(occupied_locked() == 0, "Should be clear."); 896 reset_for_par_iteration(); 897 } 898 899 void HeapRegionRemSet::reset_for_par_iteration() { 900 _iter_state = Unclaimed; 901 _iter_claimed = 0; 902 // It's good to check this to make sure that the two methods are in sync. 903 assert(verify_ready_for_par_iteration(), "post-condition"); 904 } 905 906 void HeapRegionRemSet::scrub(CardTableModRefBS* ctbs, 907 BitMap* region_bm, BitMap* card_bm) { 908 _other_regions.scrub(ctbs, region_bm, card_bm); 909 } 910 911 // Code roots support 912 // 913 // The code root set is protected by two separate locking schemes 914 // When at safepoint the per-hrrs lock must be held during modifications 915 // except when doing a full gc. 916 // When not at safepoint the CodeCache_lock must be held during modifications. 917 // When concurrent readers access the contains() function 918 // (during the evacuation phase) no removals are allowed. 919 920 void HeapRegionRemSet::add_strong_code_root(nmethod* nm) { 921 assert(nm != NULL, "sanity"); 922 // Optimistic unlocked contains-check 923 if (!_code_roots.contains(nm)) { 924 MutexLockerEx ml(&_m, Mutex::_no_safepoint_check_flag); 925 add_strong_code_root_locked(nm); 926 } 927 } 928 929 void HeapRegionRemSet::add_strong_code_root_locked(nmethod* nm) { 930 assert(nm != NULL, "sanity"); 931 _code_roots.add(nm); 932 } 933 934 void HeapRegionRemSet::remove_strong_code_root(nmethod* nm) { 935 assert(nm != NULL, "sanity"); 936 assert_locked_or_safepoint(CodeCache_lock); 937 938 MutexLockerEx ml(CodeCache_lock->owned_by_self() ? NULL : &_m, Mutex::_no_safepoint_check_flag); 939 _code_roots.remove(nm); 940 941 // Check that there were no duplicates 942 guarantee(!_code_roots.contains(nm), "duplicate entry found"); 943 } 944 945 void HeapRegionRemSet::strong_code_roots_do(CodeBlobClosure* blk) const { 946 _code_roots.nmethods_do(blk); 947 } 948 949 void HeapRegionRemSet::clean_strong_code_roots(HeapRegion* hr) { 950 _code_roots.clean(hr); 951 } 952 953 size_t HeapRegionRemSet::strong_code_roots_mem_size() { 954 return _code_roots.mem_size(); 955 } 956 957 HeapRegionRemSetIterator:: HeapRegionRemSetIterator(HeapRegionRemSet* hrrs) : 958 _hrrs(hrrs), 959 _g1h(G1CollectedHeap::heap()), 960 _coarse_map(&hrrs->_other_regions._coarse_map), 961 _bosa(hrrs->_bosa), 962 _is(Sparse), 963 // Set these values so that we increment to the first region. 964 _coarse_cur_region_index(-1), 965 _coarse_cur_region_cur_card(HeapRegion::CardsPerRegion-1), 966 _cur_card_in_prt(HeapRegion::CardsPerRegion), 967 _fine_cur_prt(NULL), 968 _n_yielded_coarse(0), 969 _n_yielded_fine(0), 970 _n_yielded_sparse(0), 971 _sparse_iter(&hrrs->_other_regions._sparse_table) {} 972 973 bool HeapRegionRemSetIterator::coarse_has_next(size_t& card_index) { 974 if (_hrrs->_other_regions._n_coarse_entries == 0) return false; 975 // Go to the next card. 976 _coarse_cur_region_cur_card++; 977 // Was the last the last card in the current region? 978 if (_coarse_cur_region_cur_card == HeapRegion::CardsPerRegion) { 979 // Yes: find the next region. This may leave _coarse_cur_region_index 980 // Set to the last index, in which case there are no more coarse 981 // regions. 982 _coarse_cur_region_index = 983 (int) _coarse_map->get_next_one_offset(_coarse_cur_region_index + 1); 984 if ((size_t)_coarse_cur_region_index < _coarse_map->size()) { 985 _coarse_cur_region_cur_card = 0; 986 HeapWord* r_bot = 987 _g1h->region_at((uint) _coarse_cur_region_index)->bottom(); 988 _cur_region_card_offset = _bosa->index_for(r_bot); 989 } else { 990 return false; 991 } 992 } 993 // If we didn't return false above, then we can yield a card. 994 card_index = _cur_region_card_offset + _coarse_cur_region_cur_card; 995 return true; 996 } 997 998 bool HeapRegionRemSetIterator::fine_has_next(size_t& card_index) { 999 if (fine_has_next()) { 1000 _cur_card_in_prt = 1001 _fine_cur_prt->_bm.get_next_one_offset(_cur_card_in_prt + 1); 1002 } 1003 if (_cur_card_in_prt == HeapRegion::CardsPerRegion) { 1004 // _fine_cur_prt may still be NULL in case if there are not PRTs at all for 1005 // the remembered set. 1006 if (_fine_cur_prt == NULL || _fine_cur_prt->next() == NULL) { 1007 return false; 1008 } 1009 PerRegionTable* next_prt = _fine_cur_prt->next(); 1010 switch_to_prt(next_prt); 1011 _cur_card_in_prt = _fine_cur_prt->_bm.get_next_one_offset(_cur_card_in_prt + 1); 1012 } 1013 1014 card_index = _cur_region_card_offset + _cur_card_in_prt; 1015 guarantee(_cur_card_in_prt < HeapRegion::CardsPerRegion, 1016 err_msg("Card index " SIZE_FORMAT " must be within the region", _cur_card_in_prt)); 1017 return true; 1018 } 1019 1020 bool HeapRegionRemSetIterator::fine_has_next() { 1021 return _cur_card_in_prt != HeapRegion::CardsPerRegion; 1022 } 1023 1024 void HeapRegionRemSetIterator::switch_to_prt(PerRegionTable* prt) { 1025 assert(prt != NULL, "Cannot switch to NULL prt"); 1026 _fine_cur_prt = prt; 1027 1028 HeapWord* r_bot = _fine_cur_prt->hr()->bottom(); 1029 _cur_region_card_offset = _bosa->index_for(r_bot); 1030 1031 // The bitmap scan for the PRT always scans from _cur_region_cur_card + 1. 1032 // To avoid special-casing this start case, and not miss the first bitmap 1033 // entry, initialize _cur_region_cur_card with -1 instead of 0. 1034 _cur_card_in_prt = (size_t)-1; 1035 } 1036 1037 bool HeapRegionRemSetIterator::has_next(size_t& card_index) { 1038 switch (_is) { 1039 case Sparse: { 1040 if (_sparse_iter.has_next(card_index)) { 1041 _n_yielded_sparse++; 1042 return true; 1043 } 1044 // Otherwise, deliberate fall-through 1045 _is = Fine; 1046 PerRegionTable* initial_fine_prt = _hrrs->_other_regions._first_all_fine_prts; 1047 if (initial_fine_prt != NULL) { 1048 switch_to_prt(_hrrs->_other_regions._first_all_fine_prts); 1049 } 1050 } 1051 case Fine: 1052 if (fine_has_next(card_index)) { 1053 _n_yielded_fine++; 1054 return true; 1055 } 1056 // Otherwise, deliberate fall-through 1057 _is = Coarse; 1058 case Coarse: 1059 if (coarse_has_next(card_index)) { 1060 _n_yielded_coarse++; 1061 return true; 1062 } 1063 // Otherwise... 1064 break; 1065 } 1066 assert(ParallelGCThreads > 1 || 1067 n_yielded() == _hrrs->occupied(), 1068 "Should have yielded all the cards in the rem set " 1069 "(in the non-par case)."); 1070 return false; 1071 } 1072 1073 1074 1075 OopOrNarrowOopStar* HeapRegionRemSet::_recorded_oops = NULL; 1076 HeapWord** HeapRegionRemSet::_recorded_cards = NULL; 1077 HeapRegion** HeapRegionRemSet::_recorded_regions = NULL; 1078 int HeapRegionRemSet::_n_recorded = 0; 1079 1080 HeapRegionRemSet::Event* HeapRegionRemSet::_recorded_events = NULL; 1081 int* HeapRegionRemSet::_recorded_event_index = NULL; 1082 int HeapRegionRemSet::_n_recorded_events = 0; 1083 1084 void HeapRegionRemSet::record(HeapRegion* hr, OopOrNarrowOopStar f) { 1085 if (_recorded_oops == NULL) { 1086 assert(_n_recorded == 0 1087 && _recorded_cards == NULL 1088 && _recorded_regions == NULL, 1089 "Inv"); 1090 _recorded_oops = NEW_C_HEAP_ARRAY(OopOrNarrowOopStar, MaxRecorded, mtGC); 1091 _recorded_cards = NEW_C_HEAP_ARRAY(HeapWord*, MaxRecorded, mtGC); 1092 _recorded_regions = NEW_C_HEAP_ARRAY(HeapRegion*, MaxRecorded, mtGC); 1093 } 1094 if (_n_recorded == MaxRecorded) { 1095 gclog_or_tty->print_cr("Filled up 'recorded' (%d).", MaxRecorded); 1096 } else { 1097 _recorded_cards[_n_recorded] = 1098 (HeapWord*)align_size_down(uintptr_t(f), 1099 CardTableModRefBS::card_size); 1100 _recorded_oops[_n_recorded] = f; 1101 _recorded_regions[_n_recorded] = hr; 1102 _n_recorded++; 1103 } 1104 } 1105 1106 void HeapRegionRemSet::record_event(Event evnt) { 1107 if (!G1RecordHRRSEvents) return; 1108 1109 if (_recorded_events == NULL) { 1110 assert(_n_recorded_events == 0 1111 && _recorded_event_index == NULL, 1112 "Inv"); 1113 _recorded_events = NEW_C_HEAP_ARRAY(Event, MaxRecordedEvents, mtGC); 1114 _recorded_event_index = NEW_C_HEAP_ARRAY(int, MaxRecordedEvents, mtGC); 1115 } 1116 if (_n_recorded_events == MaxRecordedEvents) { 1117 gclog_or_tty->print_cr("Filled up 'recorded_events' (%d).", MaxRecordedEvents); 1118 } else { 1119 _recorded_events[_n_recorded_events] = evnt; 1120 _recorded_event_index[_n_recorded_events] = _n_recorded; 1121 _n_recorded_events++; 1122 } 1123 } 1124 1125 void HeapRegionRemSet::print_event(outputStream* str, Event evnt) { 1126 switch (evnt) { 1127 case Event_EvacStart: 1128 str->print("Evac Start"); 1129 break; 1130 case Event_EvacEnd: 1131 str->print("Evac End"); 1132 break; 1133 case Event_RSUpdateEnd: 1134 str->print("RS Update End"); 1135 break; 1136 } 1137 } 1138 1139 void HeapRegionRemSet::print_recorded() { 1140 int cur_evnt = 0; 1141 Event cur_evnt_kind; 1142 int cur_evnt_ind = 0; 1143 if (_n_recorded_events > 0) { 1144 cur_evnt_kind = _recorded_events[cur_evnt]; 1145 cur_evnt_ind = _recorded_event_index[cur_evnt]; 1146 } 1147 1148 for (int i = 0; i < _n_recorded; i++) { 1149 while (cur_evnt < _n_recorded_events && i == cur_evnt_ind) { 1150 gclog_or_tty->print("Event: "); 1151 print_event(gclog_or_tty, cur_evnt_kind); 1152 gclog_or_tty->cr(); 1153 cur_evnt++; 1154 if (cur_evnt < MaxRecordedEvents) { 1155 cur_evnt_kind = _recorded_events[cur_evnt]; 1156 cur_evnt_ind = _recorded_event_index[cur_evnt]; 1157 } 1158 } 1159 gclog_or_tty->print("Added card " PTR_FORMAT " to region [" PTR_FORMAT "...]" 1160 " for ref " PTR_FORMAT ".\n", 1161 p2i(_recorded_cards[i]), p2i(_recorded_regions[i]->bottom()), 1162 p2i(_recorded_oops[i])); 1163 } 1164 } 1165 1166 void HeapRegionRemSet::reset_for_cleanup_tasks() { 1167 SparsePRT::reset_for_cleanup_tasks(); 1168 } 1169 1170 void HeapRegionRemSet::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) { 1171 _other_regions.do_cleanup_work(hrrs_cleanup_task); 1172 } 1173 1174 void 1175 HeapRegionRemSet::finish_cleanup_task(HRRSCleanupTask* hrrs_cleanup_task) { 1176 SparsePRT::finish_cleanup_task(hrrs_cleanup_task); 1177 } 1178 1179 #ifndef PRODUCT 1180 void PerRegionTable::test_fl_mem_size() { 1181 PerRegionTable* dummy = alloc(NULL); 1182 1183 size_t min_prt_size = sizeof(void*) + dummy->bm()->size_in_words() * HeapWordSize; 1184 assert(dummy->mem_size() > min_prt_size, 1185 err_msg("PerRegionTable memory usage is suspiciously small, only has " SIZE_FORMAT " bytes. " 1186 "Should be at least " SIZE_FORMAT " bytes.", dummy->mem_size(), min_prt_size)); 1187 free(dummy); 1188 guarantee(dummy->mem_size() == fl_mem_size(), "fl_mem_size() does not return the correct element size"); 1189 // try to reset the state 1190 _free_list = NULL; 1191 delete dummy; 1192 } 1193 1194 void HeapRegionRemSet::test_prt() { 1195 PerRegionTable::test_fl_mem_size(); 1196 } 1197 1198 void HeapRegionRemSet::test() { 1199 os::sleep(Thread::current(), (jlong)5000, false); 1200 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 1201 1202 // Run with "-XX:G1LogRSetRegionEntries=2", so that 1 and 5 end up in same 1203 // hash bucket. 1204 HeapRegion* hr0 = g1h->region_at(0); 1205 HeapRegion* hr1 = g1h->region_at(1); 1206 HeapRegion* hr2 = g1h->region_at(5); 1207 HeapRegion* hr3 = g1h->region_at(6); 1208 HeapRegion* hr4 = g1h->region_at(7); 1209 HeapRegion* hr5 = g1h->region_at(8); 1210 1211 HeapWord* hr1_start = hr1->bottom(); 1212 HeapWord* hr1_mid = hr1_start + HeapRegion::GrainWords/2; 1213 HeapWord* hr1_last = hr1->end() - 1; 1214 1215 HeapWord* hr2_start = hr2->bottom(); 1216 HeapWord* hr2_mid = hr2_start + HeapRegion::GrainWords/2; 1217 HeapWord* hr2_last = hr2->end() - 1; 1218 1219 HeapWord* hr3_start = hr3->bottom(); 1220 HeapWord* hr3_mid = hr3_start + HeapRegion::GrainWords/2; 1221 HeapWord* hr3_last = hr3->end() - 1; 1222 1223 HeapRegionRemSet* hrrs = hr0->rem_set(); 1224 1225 // Make three references from region 0x101... 1226 hrrs->add_reference((OopOrNarrowOopStar)hr1_start); 1227 hrrs->add_reference((OopOrNarrowOopStar)hr1_mid); 1228 hrrs->add_reference((OopOrNarrowOopStar)hr1_last); 1229 1230 hrrs->add_reference((OopOrNarrowOopStar)hr2_start); 1231 hrrs->add_reference((OopOrNarrowOopStar)hr2_mid); 1232 hrrs->add_reference((OopOrNarrowOopStar)hr2_last); 1233 1234 hrrs->add_reference((OopOrNarrowOopStar)hr3_start); 1235 hrrs->add_reference((OopOrNarrowOopStar)hr3_mid); 1236 hrrs->add_reference((OopOrNarrowOopStar)hr3_last); 1237 1238 // Now cause a coarsening. 1239 hrrs->add_reference((OopOrNarrowOopStar)hr4->bottom()); 1240 hrrs->add_reference((OopOrNarrowOopStar)hr5->bottom()); 1241 1242 // Now, does iteration yield these three? 1243 HeapRegionRemSetIterator iter(hrrs); 1244 size_t sum = 0; 1245 size_t card_index; 1246 while (iter.has_next(card_index)) { 1247 HeapWord* card_start = 1248 G1CollectedHeap::heap()->bot_shared()->address_for_index(card_index); 1249 gclog_or_tty->print_cr(" Card " PTR_FORMAT ".", p2i(card_start)); 1250 sum++; 1251 } 1252 guarantee(sum == 11 - 3 + 2048, "Failure"); 1253 guarantee(sum == hrrs->occupied(), "Failure"); 1254 } 1255 #endif