src/share/vm/gc_implementation/g1/g1ParScanThreadState.cpp

Thu, 23 Oct 2014 12:02:08 -0700

author
asaha
date
Thu, 23 Oct 2014 12:02:08 -0700
changeset 7476
c2844108a708
parent 7118
227a9e5e4b4a
child 7645
f2e3f0e1f97d
permissions
-rw-r--r--

Merge

tschatzl@6937 1 /*
tschatzl@6937 2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
tschatzl@6937 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
tschatzl@6937 4 *
tschatzl@6937 5 * This code is free software; you can redistribute it and/or modify it
tschatzl@6937 6 * under the terms of the GNU General Public License version 2 only, as
tschatzl@6937 7 * published by the Free Software Foundation.
tschatzl@6937 8 *
tschatzl@6937 9 * This code is distributed in the hope that it will be useful, but WITHOUT
tschatzl@6937 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
tschatzl@6937 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
tschatzl@6937 12 * version 2 for more details (a copy is included in the LICENSE file that
tschatzl@6937 13 * accompanied this code).
tschatzl@6937 14 *
tschatzl@6937 15 * You should have received a copy of the GNU General Public License version
tschatzl@6937 16 * 2 along with this work; if not, write to the Free Software Foundation,
tschatzl@6937 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
tschatzl@6937 18 *
tschatzl@6937 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
tschatzl@6937 20 * or visit www.oracle.com if you need additional information or have any
tschatzl@6937 21 * questions.
tschatzl@6937 22 *
tschatzl@6937 23 */
tschatzl@6937 24
tschatzl@6937 25 #include "precompiled.hpp"
tschatzl@6937 26 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
tschatzl@6937 27 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
tschatzl@6937 28 #include "gc_implementation/g1/g1ParScanThreadState.inline.hpp"
tschatzl@6937 29 #include "oops/oop.inline.hpp"
tschatzl@6937 30 #include "oops/oop.pcgc.inline.hpp"
tschatzl@6937 31 #include "runtime/prefetch.inline.hpp"
tschatzl@6937 32
tschatzl@6937 33 G1ParScanThreadState::G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num, ReferenceProcessor* rp)
tschatzl@6937 34 : _g1h(g1h),
tschatzl@6937 35 _refs(g1h->task_queue(queue_num)),
tschatzl@6937 36 _dcq(&g1h->dirty_card_queue_set()),
tschatzl@6937 37 _ct_bs(g1h->g1_barrier_set()),
tschatzl@6937 38 _g1_rem(g1h->g1_rem_set()),
tschatzl@6937 39 _hash_seed(17), _queue_num(queue_num),
tschatzl@6937 40 _term_attempts(0),
tschatzl@6939 41 _age_table(false), _scanner(g1h, rp),
sjohanss@7118 42 _strong_roots_time(0), _term_time(0) {
tschatzl@6939 43 _scanner.set_par_scan_thread_state(this);
tschatzl@6937 44 // we allocate G1YoungSurvRateNumRegions plus one entries, since
tschatzl@6937 45 // we "sacrifice" entry 0 to keep track of surviving bytes for
tschatzl@6937 46 // non-young regions (where the age is -1)
tschatzl@6937 47 // We also add a few elements at the beginning and at the end in
tschatzl@6937 48 // an attempt to eliminate cache contention
tschatzl@6937 49 uint real_length = 1 + _g1h->g1_policy()->young_cset_region_length();
tschatzl@6937 50 uint array_length = PADDING_ELEM_NUM +
tschatzl@6937 51 real_length +
tschatzl@6937 52 PADDING_ELEM_NUM;
tschatzl@6937 53 _surviving_young_words_base = NEW_C_HEAP_ARRAY(size_t, array_length, mtGC);
tschatzl@6937 54 if (_surviving_young_words_base == NULL)
tschatzl@6937 55 vm_exit_out_of_memory(array_length * sizeof(size_t), OOM_MALLOC_ERROR,
tschatzl@6937 56 "Not enough space for young surv histo.");
tschatzl@6937 57 _surviving_young_words = _surviving_young_words_base + PADDING_ELEM_NUM;
tschatzl@6937 58 memset(_surviving_young_words, 0, (size_t) real_length * sizeof(size_t));
tschatzl@6937 59
sjohanss@7118 60 _g1_par_allocator = G1ParGCAllocator::create_allocator(_g1h);
tschatzl@6937 61
tschatzl@6937 62 _start = os::elapsedTime();
tschatzl@6937 63 }
tschatzl@6937 64
tschatzl@6938 65 G1ParScanThreadState::~G1ParScanThreadState() {
sjohanss@7118 66 _g1_par_allocator->retire_alloc_buffers();
sjohanss@7118 67 delete _g1_par_allocator;
tschatzl@6938 68 FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base, mtGC);
tschatzl@6938 69 }
tschatzl@6938 70
tschatzl@6937 71 void
tschatzl@6937 72 G1ParScanThreadState::print_termination_stats_hdr(outputStream* const st)
tschatzl@6937 73 {
tschatzl@6937 74 st->print_raw_cr("GC Termination Stats");
tschatzl@6937 75 st->print_raw_cr(" elapsed --strong roots-- -------termination-------"
tschatzl@6937 76 " ------waste (KiB)------");
tschatzl@6937 77 st->print_raw_cr("thr ms ms % ms % attempts"
tschatzl@6937 78 " total alloc undo");
tschatzl@6937 79 st->print_raw_cr("--- --------- --------- ------ --------- ------ --------"
tschatzl@6937 80 " ------- ------- -------");
tschatzl@6937 81 }
tschatzl@6937 82
tschatzl@6937 83 void
tschatzl@6937 84 G1ParScanThreadState::print_termination_stats(int i,
tschatzl@6937 85 outputStream* const st) const
tschatzl@6937 86 {
tschatzl@6937 87 const double elapsed_ms = elapsed_time() * 1000.0;
tschatzl@6937 88 const double s_roots_ms = strong_roots_time() * 1000.0;
tschatzl@6937 89 const double term_ms = term_time() * 1000.0;
sjohanss@7118 90 const size_t alloc_buffer_waste = _g1_par_allocator->alloc_buffer_waste();
sjohanss@7118 91 const size_t undo_waste = _g1_par_allocator->undo_waste();
tschatzl@6937 92 st->print_cr("%3d %9.2f %9.2f %6.2f "
tschatzl@6937 93 "%9.2f %6.2f " SIZE_FORMAT_W(8) " "
tschatzl@6937 94 SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7),
tschatzl@6937 95 i, elapsed_ms, s_roots_ms, s_roots_ms * 100 / elapsed_ms,
tschatzl@6937 96 term_ms, term_ms * 100 / elapsed_ms, term_attempts(),
sjohanss@7118 97 (alloc_buffer_waste + undo_waste) * HeapWordSize / K,
sjohanss@7118 98 alloc_buffer_waste * HeapWordSize / K,
sjohanss@7118 99 undo_waste * HeapWordSize / K);
tschatzl@6937 100 }
tschatzl@6937 101
tschatzl@6937 102 #ifdef ASSERT
tschatzl@6937 103 bool G1ParScanThreadState::verify_ref(narrowOop* ref) const {
tschatzl@6937 104 assert(ref != NULL, "invariant");
tschatzl@6937 105 assert(UseCompressedOops, "sanity");
tschatzl@6937 106 assert(!has_partial_array_mask(ref), err_msg("ref=" PTR_FORMAT, p2i(ref)));
tschatzl@6937 107 oop p = oopDesc::load_decode_heap_oop(ref);
tschatzl@6937 108 assert(_g1h->is_in_g1_reserved(p),
tschatzl@6937 109 err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, p2i(ref), p2i(p)));
tschatzl@6937 110 return true;
tschatzl@6937 111 }
tschatzl@6937 112
tschatzl@6937 113 bool G1ParScanThreadState::verify_ref(oop* ref) const {
tschatzl@6937 114 assert(ref != NULL, "invariant");
tschatzl@6937 115 if (has_partial_array_mask(ref)) {
tschatzl@6937 116 // Must be in the collection set--it's already been copied.
tschatzl@6937 117 oop p = clear_partial_array_mask(ref);
tschatzl@6937 118 assert(_g1h->obj_in_cs(p),
tschatzl@6937 119 err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, p2i(ref), p2i(p)));
tschatzl@6937 120 } else {
tschatzl@6937 121 oop p = oopDesc::load_decode_heap_oop(ref);
tschatzl@6937 122 assert(_g1h->is_in_g1_reserved(p),
tschatzl@6937 123 err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, p2i(ref), p2i(p)));
tschatzl@6937 124 }
tschatzl@6937 125 return true;
tschatzl@6937 126 }
tschatzl@6937 127
tschatzl@6937 128 bool G1ParScanThreadState::verify_task(StarTask ref) const {
tschatzl@6937 129 if (ref.is_narrow()) {
tschatzl@6937 130 return verify_ref((narrowOop*) ref);
tschatzl@6937 131 } else {
tschatzl@6937 132 return verify_ref((oop*) ref);
tschatzl@6937 133 }
tschatzl@6937 134 }
tschatzl@6937 135 #endif // ASSERT
tschatzl@6937 136
tschatzl@6937 137 void G1ParScanThreadState::trim_queue() {
tschatzl@6937 138 assert(_evac_failure_cl != NULL, "not set");
tschatzl@6937 139
tschatzl@6937 140 StarTask ref;
tschatzl@6937 141 do {
tschatzl@6937 142 // Drain the overflow stack first, so other threads can steal.
tschatzl@6938 143 while (_refs->pop_overflow(ref)) {
tschatzl@6938 144 dispatch_reference(ref);
tschatzl@6937 145 }
tschatzl@6937 146
tschatzl@6938 147 while (_refs->pop_local(ref)) {
tschatzl@6938 148 dispatch_reference(ref);
tschatzl@6937 149 }
tschatzl@6938 150 } while (!_refs->is_empty());
tschatzl@6937 151 }
tschatzl@6937 152
tschatzl@6937 153 oop G1ParScanThreadState::copy_to_survivor_space(oop const old) {
tschatzl@6937 154 size_t word_sz = old->size();
tschatzl@6937 155 HeapRegion* from_region = _g1h->heap_region_containing_raw(old);
tschatzl@6937 156 // +1 to make the -1 indexes valid...
tschatzl@6937 157 int young_index = from_region->young_index_in_cset()+1;
tschatzl@6937 158 assert( (from_region->is_young() && young_index > 0) ||
tschatzl@6937 159 (!from_region->is_young() && young_index == 0), "invariant" );
tschatzl@6937 160 G1CollectorPolicy* g1p = _g1h->g1_policy();
tschatzl@6937 161 markOop m = old->mark();
tschatzl@6937 162 int age = m->has_displaced_mark_helper() ? m->displaced_mark_helper()->age()
tschatzl@6937 163 : m->age();
tschatzl@6937 164 GCAllocPurpose alloc_purpose = g1p->evacuation_destination(from_region, age,
tschatzl@6937 165 word_sz);
sjohanss@7118 166 AllocationContext_t context = from_region->allocation_context();
sjohanss@7118 167 HeapWord* obj_ptr = _g1_par_allocator->allocate(alloc_purpose, word_sz, context);
tschatzl@6937 168 #ifndef PRODUCT
tschatzl@6937 169 // Should this evacuation fail?
tschatzl@6937 170 if (_g1h->evacuation_should_fail()) {
tschatzl@6937 171 if (obj_ptr != NULL) {
sjohanss@7118 172 _g1_par_allocator->undo_allocation(alloc_purpose, obj_ptr, word_sz, context);
tschatzl@6937 173 obj_ptr = NULL;
tschatzl@6937 174 }
tschatzl@6937 175 }
tschatzl@6937 176 #endif // !PRODUCT
tschatzl@6937 177
tschatzl@6937 178 if (obj_ptr == NULL) {
tschatzl@6937 179 // This will either forward-to-self, or detect that someone else has
tschatzl@6937 180 // installed a forwarding pointer.
tschatzl@6937 181 return _g1h->handle_evacuation_failure_par(this, old);
tschatzl@6937 182 }
tschatzl@6937 183
tschatzl@6937 184 oop obj = oop(obj_ptr);
tschatzl@6937 185
tschatzl@6937 186 // We're going to allocate linearly, so might as well prefetch ahead.
tschatzl@6937 187 Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes);
tschatzl@6937 188
tschatzl@6937 189 oop forward_ptr = old->forward_to_atomic(obj);
tschatzl@6937 190 if (forward_ptr == NULL) {
tschatzl@6937 191 Copy::aligned_disjoint_words((HeapWord*) old, obj_ptr, word_sz);
tschatzl@6937 192
tschatzl@6937 193 // alloc_purpose is just a hint to allocate() above, recheck the type of region
tschatzl@6937 194 // we actually allocated from and update alloc_purpose accordingly
tschatzl@6937 195 HeapRegion* to_region = _g1h->heap_region_containing_raw(obj_ptr);
tschatzl@6937 196 alloc_purpose = to_region->is_young() ? GCAllocForSurvived : GCAllocForTenured;
tschatzl@6937 197
tschatzl@6937 198 if (g1p->track_object_age(alloc_purpose)) {
tschatzl@6937 199 // We could simply do obj->incr_age(). However, this causes a
tschatzl@6937 200 // performance issue. obj->incr_age() will first check whether
tschatzl@6937 201 // the object has a displaced mark by checking its mark word;
tschatzl@6937 202 // getting the mark word from the new location of the object
tschatzl@6937 203 // stalls. So, given that we already have the mark word and we
tschatzl@6937 204 // are about to install it anyway, it's better to increase the
tschatzl@6937 205 // age on the mark word, when the object does not have a
tschatzl@6937 206 // displaced mark word. We're not expecting many objects to have
tschatzl@6937 207 // a displaced marked word, so that case is not optimized
tschatzl@6937 208 // further (it could be...) and we simply call obj->incr_age().
tschatzl@6937 209
tschatzl@6937 210 if (m->has_displaced_mark_helper()) {
tschatzl@6937 211 // in this case, we have to install the mark word first,
tschatzl@6937 212 // otherwise obj looks to be forwarded (the old mark word,
tschatzl@6937 213 // which contains the forward pointer, was copied)
tschatzl@6937 214 obj->set_mark(m);
tschatzl@6937 215 obj->incr_age();
tschatzl@6937 216 } else {
tschatzl@6937 217 m = m->incr_age();
tschatzl@6937 218 obj->set_mark(m);
tschatzl@6937 219 }
tschatzl@6937 220 age_table()->add(obj, word_sz);
tschatzl@6937 221 } else {
tschatzl@6937 222 obj->set_mark(m);
tschatzl@6937 223 }
tschatzl@6937 224
tschatzl@6937 225 if (G1StringDedup::is_enabled()) {
tschatzl@6937 226 G1StringDedup::enqueue_from_evacuation(from_region->is_young(),
tschatzl@6937 227 to_region->is_young(),
tschatzl@6937 228 queue_num(),
tschatzl@6937 229 obj);
tschatzl@6937 230 }
tschatzl@6937 231
tschatzl@6937 232 size_t* surv_young_words = surviving_young_words();
tschatzl@6937 233 surv_young_words[young_index] += word_sz;
tschatzl@6937 234
tschatzl@6937 235 if (obj->is_objArray() && arrayOop(obj)->length() >= ParGCArrayScanChunk) {
tschatzl@6937 236 // We keep track of the next start index in the length field of
tschatzl@6937 237 // the to-space object. The actual length can be found in the
tschatzl@6937 238 // length field of the from-space object.
tschatzl@6937 239 arrayOop(obj)->set_length(0);
tschatzl@6937 240 oop* old_p = set_partial_array_mask(old);
tschatzl@6937 241 push_on_queue(old_p);
tschatzl@6937 242 } else {
tschatzl@6937 243 // No point in using the slower heap_region_containing() method,
tschatzl@6937 244 // given that we know obj is in the heap.
tschatzl@6937 245 _scanner.set_region(_g1h->heap_region_containing_raw(obj));
tschatzl@6937 246 obj->oop_iterate_backwards(&_scanner);
tschatzl@6937 247 }
tschatzl@6937 248 } else {
sjohanss@7118 249 _g1_par_allocator->undo_allocation(alloc_purpose, obj_ptr, word_sz, context);
tschatzl@6937 250 obj = forward_ptr;
tschatzl@6937 251 }
tschatzl@6937 252 return obj;
tschatzl@6937 253 }

mercurial