rev 6480 : imported patch 8035400-move-g1parscanthreadstate-into-own-files rev 6481 : imported patch 8035400-2-bengt-fixes rev 6482 : imported patch 8035401-fix-visibility-of-g1parscanthreadstate rev 6483 : imported patch 8035401-3-fix-constructor rev 6484 : [mq]: 8035401-2-another-inline-try rev 6485 : [mq]: 8040977-g1-crashes-with-G1DeferredRSUpdate-disabled
1 /* 2 * Copyright (c) 2014, 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_implementation/g1/g1CollectedHeap.inline.hpp" 27 #include "gc_implementation/g1/g1OopClosures.inline.hpp" 28 #include "gc_implementation/g1/g1ParScanThreadState.inline.hpp" 29 #include "oops/oop.inline.hpp" 30 #include "oops/oop.pcgc.inline.hpp" 31 #include "runtime/prefetch.inline.hpp" 32 33 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away 34 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list 35 #endif // _MSC_VER 36 37 G1ParScanThreadState::G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num, ReferenceProcessor* rp) 38 : _g1h(g1h), 39 _refs(g1h->task_queue(queue_num)), 40 _dcq(&g1h->dirty_card_queue_set()), 41 _ct_bs(g1h->g1_barrier_set()), 42 _g1_rem(g1h->g1_rem_set()), 43 _hash_seed(17), _queue_num(queue_num), 44 _term_attempts(0), 45 _surviving_alloc_buffer(g1h->desired_plab_sz(GCAllocForSurvived)), 46 _tenured_alloc_buffer(g1h->desired_plab_sz(GCAllocForTenured)), 47 _age_table(false), _scanner(g1h, this, rp), 48 _strong_roots_time(0), _term_time(0), 49 _alloc_buffer_waste(0), _undo_waste(0) { 50 // we allocate G1YoungSurvRateNumRegions plus one entries, since 51 // we "sacrifice" entry 0 to keep track of surviving bytes for 52 // non-young regions (where the age is -1) 53 // We also add a few elements at the beginning and at the end in 54 // an attempt to eliminate cache contention 55 uint real_length = 1 + _g1h->g1_policy()->young_cset_region_length(); 56 uint array_length = PADDING_ELEM_NUM + 57 real_length + 58 PADDING_ELEM_NUM; 59 _surviving_young_words_base = NEW_C_HEAP_ARRAY(size_t, array_length, mtGC); 60 if (_surviving_young_words_base == NULL) 61 vm_exit_out_of_memory(array_length * sizeof(size_t), OOM_MALLOC_ERROR, 62 "Not enough space for young surv histo."); 63 _surviving_young_words = _surviving_young_words_base + PADDING_ELEM_NUM; 64 memset(_surviving_young_words, 0, (size_t) real_length * sizeof(size_t)); 65 66 _alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer; 67 _alloc_buffers[GCAllocForTenured] = &_tenured_alloc_buffer; 68 69 _start = os::elapsedTime(); 70 } 71 72 G1ParScanThreadState::~G1ParScanThreadState() { 73 retire_alloc_buffers(); 74 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base, mtGC); 75 } 76 77 void 78 G1ParScanThreadState::print_termination_stats_hdr(outputStream* const st) 79 { 80 st->print_raw_cr("GC Termination Stats"); 81 st->print_raw_cr(" elapsed --strong roots-- -------termination-------" 82 " ------waste (KiB)------"); 83 st->print_raw_cr("thr ms ms % ms % attempts" 84 " total alloc undo"); 85 st->print_raw_cr("--- --------- --------- ------ --------- ------ --------" 86 " ------- ------- -------"); 87 } 88 89 void 90 G1ParScanThreadState::print_termination_stats(int i, 91 outputStream* const st) const 92 { 93 const double elapsed_ms = elapsed_time() * 1000.0; 94 const double s_roots_ms = strong_roots_time() * 1000.0; 95 const double term_ms = term_time() * 1000.0; 96 st->print_cr("%3d %9.2f %9.2f %6.2f " 97 "%9.2f %6.2f " SIZE_FORMAT_W(8) " " 98 SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7), 99 i, elapsed_ms, s_roots_ms, s_roots_ms * 100 / elapsed_ms, 100 term_ms, term_ms * 100 / elapsed_ms, term_attempts(), 101 (alloc_buffer_waste() + undo_waste()) * HeapWordSize / K, 102 alloc_buffer_waste() * HeapWordSize / K, 103 undo_waste() * HeapWordSize / K); 104 } 105 106 #ifdef ASSERT 107 bool G1ParScanThreadState::verify_ref(narrowOop* ref) const { 108 assert(ref != NULL, "invariant"); 109 assert(UseCompressedOops, "sanity"); 110 assert(!has_partial_array_mask(ref), err_msg("ref=" PTR_FORMAT, p2i(ref))); 111 oop p = oopDesc::load_decode_heap_oop(ref); 112 assert(_g1h->is_in_g1_reserved(p), 113 err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, p2i(ref), p2i(p))); 114 return true; 115 } 116 117 bool G1ParScanThreadState::verify_ref(oop* ref) const { 118 assert(ref != NULL, "invariant"); 119 if (has_partial_array_mask(ref)) { 120 // Must be in the collection set--it's already been copied. 121 oop p = clear_partial_array_mask(ref); 122 assert(_g1h->obj_in_cs(p), 123 err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, p2i(ref), p2i(p))); 124 } else { 125 oop p = oopDesc::load_decode_heap_oop(ref); 126 assert(_g1h->is_in_g1_reserved(p), 127 err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, p2i(ref), p2i(p))); 128 } 129 return true; 130 } 131 132 bool G1ParScanThreadState::verify_task(StarTask ref) const { 133 if (ref.is_narrow()) { 134 return verify_ref((narrowOop*) ref); 135 } else { 136 return verify_ref((oop*) ref); 137 } 138 } 139 #endif // ASSERT 140 141 void G1ParScanThreadState::trim_queue() { 142 assert(_evac_failure_cl != NULL, "not set"); 143 144 StarTask ref; 145 do { 146 // Drain the overflow stack first, so other threads can steal. 147 while (_refs->pop_overflow(ref)) { 148 dispatch_reference(ref); 149 } 150 151 while (_refs->pop_local(ref)) { 152 dispatch_reference(ref); 153 } 154 } while (!_refs->is_empty()); 155 } 156 157 oop G1ParScanThreadState::copy_to_survivor_space(oop const old) { 158 size_t word_sz = old->size(); 159 HeapRegion* from_region = _g1h->heap_region_containing_raw(old); 160 // +1 to make the -1 indexes valid... 161 int young_index = from_region->young_index_in_cset()+1; 162 assert( (from_region->is_young() && young_index > 0) || 163 (!from_region->is_young() && young_index == 0), "invariant" ); 164 G1CollectorPolicy* g1p = _g1h->g1_policy(); 165 markOop m = old->mark(); 166 int age = m->has_displaced_mark_helper() ? m->displaced_mark_helper()->age() 167 : m->age(); 168 GCAllocPurpose alloc_purpose = g1p->evacuation_destination(from_region, age, 169 word_sz); 170 HeapWord* obj_ptr = allocate(alloc_purpose, word_sz); 171 #ifndef PRODUCT 172 // Should this evacuation fail? 173 if (_g1h->evacuation_should_fail()) { 174 if (obj_ptr != NULL) { 175 undo_allocation(alloc_purpose, obj_ptr, word_sz); 176 obj_ptr = NULL; 177 } 178 } 179 #endif // !PRODUCT 180 181 if (obj_ptr == NULL) { 182 // This will either forward-to-self, or detect that someone else has 183 // installed a forwarding pointer. 184 return _g1h->handle_evacuation_failure_par(this, old); 185 } 186 187 oop obj = oop(obj_ptr); 188 189 // We're going to allocate linearly, so might as well prefetch ahead. 190 Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes); 191 192 oop forward_ptr = old->forward_to_atomic(obj); 193 if (forward_ptr == NULL) { 194 Copy::aligned_disjoint_words((HeapWord*) old, obj_ptr, word_sz); 195 196 // alloc_purpose is just a hint to allocate() above, recheck the type of region 197 // we actually allocated from and update alloc_purpose accordingly 198 HeapRegion* to_region = _g1h->heap_region_containing_raw(obj_ptr); 199 alloc_purpose = to_region->is_young() ? GCAllocForSurvived : GCAllocForTenured; 200 201 if (g1p->track_object_age(alloc_purpose)) { 202 // We could simply do obj->incr_age(). However, this causes a 203 // performance issue. obj->incr_age() will first check whether 204 // the object has a displaced mark by checking its mark word; 205 // getting the mark word from the new location of the object 206 // stalls. So, given that we already have the mark word and we 207 // are about to install it anyway, it's better to increase the 208 // age on the mark word, when the object does not have a 209 // displaced mark word. We're not expecting many objects to have 210 // a displaced marked word, so that case is not optimized 211 // further (it could be...) and we simply call obj->incr_age(). 212 213 if (m->has_displaced_mark_helper()) { 214 // in this case, we have to install the mark word first, 215 // otherwise obj looks to be forwarded (the old mark word, 216 // which contains the forward pointer, was copied) 217 obj->set_mark(m); 218 obj->incr_age(); 219 } else { 220 m = m->incr_age(); 221 obj->set_mark(m); 222 } 223 age_table()->add(obj, word_sz); 224 } else { 225 obj->set_mark(m); 226 } 227 228 if (G1StringDedup::is_enabled()) { 229 G1StringDedup::enqueue_from_evacuation(from_region->is_young(), 230 to_region->is_young(), 231 queue_num(), 232 obj); 233 } 234 235 size_t* surv_young_words = surviving_young_words(); 236 surv_young_words[young_index] += word_sz; 237 238 if (obj->is_objArray() && arrayOop(obj)->length() >= ParGCArrayScanChunk) { 239 // We keep track of the next start index in the length field of 240 // the to-space object. The actual length can be found in the 241 // length field of the from-space object. 242 arrayOop(obj)->set_length(0); 243 oop* old_p = set_partial_array_mask(old); 244 push_on_queue(old_p); 245 } else { 246 // No point in using the slower heap_region_containing() method, 247 // given that we know obj is in the heap. 248 _scanner.set_region(_g1h->heap_region_containing_raw(obj)); 249 obj->oop_iterate_backwards(&_scanner); 250 } 251 } else { 252 undo_allocation(alloc_purpose, obj_ptr, word_sz); 253 obj = forward_ptr; 254 } 255 return obj; 256 } 257 258 HeapWord* G1ParScanThreadState::allocate_slow(GCAllocPurpose purpose, size_t word_sz) { 259 HeapWord* obj = NULL; 260 size_t gclab_word_size = _g1h->desired_plab_sz(purpose); 261 if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) { 262 G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose); 263 add_to_alloc_buffer_waste(alloc_buf->words_remaining()); 264 alloc_buf->retire(false /* end_of_gc */, false /* retain */); 265 266 HeapWord* buf = _g1h->par_allocate_during_gc(purpose, gclab_word_size); 267 if (buf == NULL) { 268 return NULL; // Let caller handle allocation failure. 269 } 270 // Otherwise. 271 alloc_buf->set_word_size(gclab_word_size); 272 alloc_buf->set_buf(buf); 273 274 obj = alloc_buf->allocate(word_sz); 275 assert(obj != NULL, "buffer was definitely big enough..."); 276 } else { 277 obj = _g1h->par_allocate_during_gc(purpose, word_sz); 278 } 279 return obj; 280 } 281 282 void G1ParScanThreadState::undo_allocation(GCAllocPurpose purpose, HeapWord* obj, size_t word_sz) { 283 if (alloc_buffer(purpose)->contains(obj)) { 284 assert(alloc_buffer(purpose)->contains(obj + word_sz - 1), 285 "should contain whole object"); 286 alloc_buffer(purpose)->undo_allocation(obj, word_sz); 287 } else { 288 CollectedHeap::fill_with_object(obj, word_sz); 289 add_to_undo_waste(word_sz); 290 } 291 } 292 293 HeapWord* G1ParScanThreadState::allocate(GCAllocPurpose purpose, size_t word_sz) { 294 HeapWord* obj = alloc_buffer(purpose)->allocate(word_sz); 295 if (obj != NULL) { 296 return obj; 297 } 298 return allocate_slow(purpose, word_sz); 299 } 300 301 void G1ParScanThreadState::retire_alloc_buffers() { 302 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { 303 size_t waste = _alloc_buffers[ap]->words_remaining(); 304 add_to_alloc_buffer_waste(waste); 305 _alloc_buffers[ap]->flush_stats_and_retire(_g1h->stats_for_purpose((GCAllocPurpose)ap), 306 true /* end_of_gc */, 307 false /* retain */); 308 } 309 } --- EOF ---