ysr@777: /* drchase@6680: * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved. ysr@777: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. ysr@777: * ysr@777: * This code is free software; you can redistribute it and/or modify it ysr@777: * under the terms of the GNU General Public License version 2 only, as ysr@777: * published by the Free Software Foundation. ysr@777: * ysr@777: * This code is distributed in the hope that it will be useful, but WITHOUT ysr@777: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or ysr@777: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License ysr@777: * version 2 for more details (a copy is included in the LICENSE file that ysr@777: * accompanied this code). ysr@777: * ysr@777: * You should have received a copy of the GNU General Public License version ysr@777: * 2 along with this work; if not, write to the Free Software Foundation, ysr@777: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. ysr@777: * trims@1907: * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA trims@1907: * or visit www.oracle.com if you need additional information or have any trims@1907: * questions. ysr@777: * ysr@777: */ ysr@777: stefank@2314: #include "precompiled.hpp" stefank@2314: #include "gc_implementation/g1/concurrentG1Refine.hpp" stefank@2314: #include "gc_implementation/g1/concurrentG1RefineThread.hpp" stefank@2314: #include "gc_implementation/g1/g1BlockOffsetTable.inline.hpp" stefank@2314: #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" stefank@2314: #include "gc_implementation/g1/g1CollectorPolicy.hpp" johnc@5078: #include "gc_implementation/g1/g1HotCardCache.hpp" brutisso@3923: #include "gc_implementation/g1/g1GCPhaseTimes.hpp" stefank@2314: #include "gc_implementation/g1/g1OopClosures.inline.hpp" stefank@2314: #include "gc_implementation/g1/g1RemSet.inline.hpp" tschatzl@7091: #include "gc_implementation/g1/heapRegionManager.inline.hpp" tschatzl@5204: #include "gc_implementation/g1/heapRegionRemSet.hpp" stefank@2314: #include "memory/iterator.hpp" stefank@2314: #include "oops/oop.inline.hpp" stefank@2314: #include "utilities/intHisto.hpp" ysr@777: drchase@6680: PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC drchase@6680: ysr@777: #define CARD_REPEAT_HISTO 0 ysr@777: ysr@777: #if CARD_REPEAT_HISTO ysr@777: static size_t ct_freq_sz; ysr@777: static jbyte* ct_freq = NULL; ysr@777: ysr@777: void init_ct_freq_table(size_t heap_sz_bytes) { ysr@777: if (ct_freq == NULL) { ysr@777: ct_freq_sz = heap_sz_bytes/CardTableModRefBS::card_size; ysr@777: ct_freq = new jbyte[ct_freq_sz]; ysr@777: for (size_t j = 0; j < ct_freq_sz; j++) ct_freq[j] = 0; ysr@777: } ysr@777: } ysr@777: ysr@777: void ct_freq_note_card(size_t index) { ysr@777: assert(0 <= index && index < ct_freq_sz, "Bounds error."); ysr@777: if (ct_freq[index] < 100) { ct_freq[index]++; } ysr@777: } ysr@777: ysr@777: static IntHistogram card_repeat_count(10, 10); ysr@777: ysr@777: void ct_freq_update_histo_and_reset() { ysr@777: for (size_t j = 0; j < ct_freq_sz; j++) { ysr@777: card_repeat_count.add_entry(ct_freq[j]); ysr@777: ct_freq[j] = 0; ysr@777: } ysr@777: ysr@777: } ysr@777: #endif ysr@777: johnc@2216: G1RemSet::G1RemSet(G1CollectedHeap* g1, CardTableModRefBS* ct_bs) johnc@2216: : _g1(g1), _conc_refine_cards(0), johnc@2216: _ct_bs(ct_bs), _g1p(_g1->g1_policy()), ysr@777: _cg1r(g1->concurrent_g1_refine()), johnc@2060: _cset_rs_update_cl(NULL), tschatzl@5204: _cards_scanned(NULL), _total_cards_scanned(0), tschatzl@5204: _prev_period_summary() ysr@777: { ysr@777: _seq_task = new SubTasksDone(NumSeqTasks); iveresov@1051: guarantee(n_workers() > 0, "There should be some workers"); mgerdin@7971: _cset_rs_update_cl = NEW_C_HEAP_ARRAY(G1ParPushHeapRSClosure*, n_workers(), mtGC); iveresov@1051: for (uint i = 0; i < n_workers(); i++) { johnc@2060: _cset_rs_update_cl[i] = NULL; iveresov@1051: } tschatzl@5812: if (G1SummarizeRSetStats) { tschatzl@5812: _prev_period_summary.initialize(this); tschatzl@5812: } ysr@777: } ysr@777: johnc@2216: G1RemSet::~G1RemSet() { ysr@777: delete _seq_task; iveresov@1051: for (uint i = 0; i < n_workers(); i++) { johnc@2060: assert(_cset_rs_update_cl[i] == NULL, "it should be"); iveresov@1051: } mgerdin@7971: FREE_C_HEAP_ARRAY(G1ParPushHeapRSClosure*, _cset_rs_update_cl, mtGC); ysr@777: } ysr@777: ysr@777: void CountNonCleanMemRegionClosure::do_MemRegion(MemRegion mr) { ysr@777: if (_g1->is_in_g1_reserved(mr.start())) { ysr@777: _n += (int) ((mr.byte_size() / CardTableModRefBS::card_size)); ysr@777: if (_start_first == NULL) _start_first = mr.start(); ysr@777: } ysr@777: } ysr@777: ysr@777: class ScanRSClosure : public HeapRegionClosure { ysr@777: size_t _cards_done, _cards; ysr@777: G1CollectedHeap* _g1h; johnc@5548: mgerdin@7971: G1ParPushHeapRSClosure* _oc; mgerdin@7208: CodeBlobClosure* _code_root_cl; johnc@5548: ysr@777: G1BlockOffsetSharedArray* _bot_shared; mgerdin@5811: G1SATBCardTableModRefBS *_ct_bs; johnc@5548: johnc@5548: double _strong_code_root_scan_time_sec; vkempik@6552: uint _worker_i; johnc@5548: int _block_size; johnc@5548: bool _try_claimed; johnc@5548: ysr@777: public: mgerdin@7971: ScanRSClosure(G1ParPushHeapRSClosure* oc, mgerdin@7208: CodeBlobClosure* code_root_cl, vkempik@6552: uint worker_i) : ysr@777: _oc(oc), johnc@5548: _code_root_cl(code_root_cl), johnc@5548: _strong_code_root_scan_time_sec(0.0), ysr@777: _cards(0), ysr@777: _cards_done(0), ysr@777: _worker_i(worker_i), ysr@777: _try_claimed(false) ysr@777: { ysr@777: _g1h = G1CollectedHeap::heap(); ysr@777: _bot_shared = _g1h->bot_shared(); mgerdin@5811: _ct_bs = _g1h->g1_barrier_set(); iveresov@1696: _block_size = MAX2(G1RSetScanBlockSize, 1); ysr@777: } ysr@777: ysr@777: void set_try_claimed() { _try_claimed = true; } ysr@777: ysr@777: void scanCard(size_t index, HeapRegion *r) { johnc@3219: // Stack allocate the DirtyCardToOopClosure instance johnc@3219: HeapRegionDCTOC cl(_g1h, r, _oc, mgerdin@7971: CardTableModRefBS::Precise); ysr@777: ysr@777: // Set the "from" region in the closure. ysr@777: _oc->set_region(r); ysr@777: HeapWord* card_start = _bot_shared->address_for_index(index); ysr@777: HeapWord* card_end = card_start + G1BlockOffsetSharedArray::N_words; ysr@777: Space *sp = SharedHeap::heap()->space_containing(card_start); tonyp@2849: MemRegion sm_region = sp->used_region_at_save_marks(); ysr@777: MemRegion mr = sm_region.intersection(MemRegion(card_start,card_end)); tonyp@2849: if (!mr.is_empty() && !_ct_bs->is_card_claimed(index)) { tonyp@2849: // We make the card as "claimed" lazily (so races are possible tonyp@2849: // but they're benign), which reduces the number of duplicate tonyp@2849: // scans (the rsets of the regions in the cset can intersect). tonyp@2849: _ct_bs->set_card_claimed(index); tonyp@2849: _cards_done++; johnc@3219: cl.do_MemRegion(mr); ysr@777: } ysr@777: } ysr@777: ysr@777: void printCard(HeapRegion* card_region, size_t card_index, ysr@777: HeapWord* card_start) { vkempik@6552: gclog_or_tty->print_cr("T " UINT32_FORMAT " Region [" PTR_FORMAT ", " PTR_FORMAT ") " ysr@777: "RS names card %p: " ysr@777: "[" PTR_FORMAT ", " PTR_FORMAT ")", ysr@777: _worker_i, ysr@777: card_region->bottom(), card_region->end(), ysr@777: card_index, ysr@777: card_start, card_start + G1BlockOffsetSharedArray::N_words); ysr@777: } ysr@777: johnc@5548: void scan_strong_code_roots(HeapRegion* r) { johnc@5548: double scan_start = os::elapsedTime(); johnc@5548: r->strong_code_roots_do(_code_root_cl); johnc@5548: _strong_code_root_scan_time_sec += (os::elapsedTime() - scan_start); johnc@5548: } johnc@5548: ysr@777: bool doHeapRegion(HeapRegion* r) { ysr@777: assert(r->in_collection_set(), "should only be called on elements of CS."); ysr@777: HeapRegionRemSet* hrrs = r->rem_set(); ysr@777: if (hrrs->iter_is_complete()) return false; // All done. ysr@777: if (!_try_claimed && !hrrs->claim_iter()) return false; tonyp@2849: // If we ever free the collection set concurrently, we should also tonyp@2849: // clear the card table concurrently therefore we won't need to tonyp@2849: // add regions of the collection set to the dirty cards region. apetrusenko@1231: _g1h->push_dirty_cards_region(r); ysr@777: // If we didn't return above, then ysr@777: // _try_claimed || r->claim_iter() ysr@777: // is true: either we're supposed to work on claimed-but-not-complete ysr@777: // regions, or we successfully claimed the region. johnc@5548: johnc@5014: HeapRegionRemSetIterator iter(hrrs); ysr@777: size_t card_index; iveresov@1696: iveresov@1696: // We claim cards in block so as to recude the contention. The block size is determined by iveresov@1696: // the G1RSetScanBlockSize parameter. iveresov@1696: size_t jump_to_card = hrrs->iter_claimed_next(_block_size); johnc@5014: for (size_t current_card = 0; iter.has_next(card_index); current_card++) { iveresov@1696: if (current_card >= jump_to_card + _block_size) { iveresov@1696: jump_to_card = hrrs->iter_claimed_next(_block_size); iveresov@1182: } iveresov@1696: if (current_card < jump_to_card) continue; ysr@777: HeapWord* card_start = _g1h->bot_shared()->address_for_index(card_index); ysr@777: #if 0 ysr@777: gclog_or_tty->print("Rem set iteration yielded card [" PTR_FORMAT ", " PTR_FORMAT ").\n", ysr@777: card_start, card_start + CardTableModRefBS::card_size_in_words); ysr@777: #endif ysr@777: ysr@777: HeapRegion* card_region = _g1h->heap_region_containing(card_start); ysr@777: _cards++; ysr@777: apetrusenko@1231: if (!card_region->is_on_dirty_cards_region_list()) { apetrusenko@1231: _g1h->push_dirty_cards_region(card_region); apetrusenko@1231: } apetrusenko@1231: tonyp@2849: // If the card is dirty, then we will scan it during updateRS. tonyp@2849: if (!card_region->in_collection_set() && tonyp@2849: !_ct_bs->is_card_dirty(card_index)) { tonyp@2849: scanCard(card_index, card_region); ysr@777: } ysr@777: } iveresov@1182: if (!_try_claimed) { johnc@5548: // Scan the strong code root list attached to the current region johnc@5548: scan_strong_code_roots(r); johnc@5548: iveresov@1182: hrrs->set_iter_complete(); iveresov@1182: } ysr@777: return false; ysr@777: } johnc@5548: johnc@5548: double strong_code_root_scan_time_sec() { johnc@5548: return _strong_code_root_scan_time_sec; johnc@5548: } johnc@5548: ysr@777: size_t cards_done() { return _cards_done;} ysr@777: size_t cards_looked_up() { return _cards;} ysr@777: }; ysr@777: mgerdin@7971: void G1RemSet::scanRS(G1ParPushHeapRSClosure* oc, mgerdin@7208: CodeBlobClosure* code_root_cl, vkempik@6552: uint worker_i) { ysr@777: double rs_time_start = os::elapsedTime(); johnc@3296: HeapRegion *startRegion = _g1->start_cset_region_for_worker(worker_i); ysr@777: johnc@5548: ScanRSClosure scanRScl(oc, code_root_cl, worker_i); johnc@3175: ysr@777: _g1->collection_set_iterate_from(startRegion, &scanRScl); ysr@777: scanRScl.set_try_claimed(); ysr@777: _g1->collection_set_iterate_from(startRegion, &scanRScl); ysr@777: johnc@5548: double scan_rs_time_sec = (os::elapsedTime() - rs_time_start) johnc@5548: - scanRScl.strong_code_root_scan_time_sec(); ysr@777: johnc@5548: assert(_cards_scanned != NULL, "invariant"); ysr@777: _cards_scanned[worker_i] = scanRScl.cards_done(); ysr@777: brutisso@3923: _g1p->phase_times()->record_scan_rs_time(worker_i, scan_rs_time_sec * 1000.0); johnc@5548: _g1p->phase_times()->record_strong_code_root_scan_time(worker_i, johnc@5548: scanRScl.strong_code_root_scan_time_sec() * 1000.0); ysr@777: } ysr@777: johnc@2060: // Closure used for updating RSets and recording references that johnc@2060: // point into the collection set. Only called during an johnc@2060: // evacuation pause. ysr@777: johnc@2060: class RefineRecordRefsIntoCSCardTableEntryClosure: public CardTableEntryClosure { johnc@2060: G1RemSet* _g1rs; johnc@2060: DirtyCardQueue* _into_cset_dcq; johnc@2060: public: johnc@2060: RefineRecordRefsIntoCSCardTableEntryClosure(G1CollectedHeap* g1h, johnc@2060: DirtyCardQueue* into_cset_dcq) : johnc@2060: _g1rs(g1h->g1_rem_set()), _into_cset_dcq(into_cset_dcq) johnc@2060: {} vkempik@6552: bool do_card_ptr(jbyte* card_ptr, uint worker_i) { johnc@2060: // The only time we care about recording cards that johnc@2060: // contain references that point into the collection set johnc@2060: // is during RSet updating within an evacuation pause. johnc@2060: // In this case worker_i should be the id of a GC worker thread. johnc@2060: assert(SafepointSynchronize::is_at_safepoint(), "not during an evacuation pause"); vkempik@6552: assert(worker_i < (ParallelGCThreads == 0 ? 1 : ParallelGCThreads), "should be a GC worker"); johnc@2060: johnc@5078: if (_g1rs->refine_card(card_ptr, worker_i, true)) { johnc@2060: // 'card_ptr' contains references that point into the collection johnc@2060: // set. We need to record the card in the DCQS johnc@2060: // (G1CollectedHeap::into_cset_dirty_card_queue_set()) johnc@2060: // that's used for that purpose. johnc@2060: // johnc@2060: // Enqueue the card johnc@2060: _into_cset_dcq->enqueue(card_ptr); johnc@2060: } johnc@2060: return true; johnc@2060: } johnc@2060: }; johnc@2060: vkempik@6552: void G1RemSet::updateRS(DirtyCardQueue* into_cset_dcq, uint worker_i) { ysr@777: double start = os::elapsedTime(); johnc@2060: // Apply the given closure to all remaining log entries. johnc@2060: RefineRecordRefsIntoCSCardTableEntryClosure into_cset_update_rs_cl(_g1, into_cset_dcq); johnc@3175: johnc@2060: _g1->iterate_dirty_card_closure(&into_cset_update_rs_cl, into_cset_dcq, false, worker_i); johnc@2060: iveresov@1229: // Now there should be no dirty cards. iveresov@1229: if (G1RSLogCheckCardTable) { iveresov@1229: CountNonCleanMemRegionClosure cl(_g1); iveresov@1229: _ct_bs->mod_card_iterate(&cl); iveresov@1229: // XXX This isn't true any more: keeping cards of young regions iveresov@1229: // marked dirty broke it. Need some reasonable fix. iveresov@1229: guarantee(cl.n() == 0, "Card table should be clean."); ysr@777: } iveresov@1229: brutisso@3923: _g1p->phase_times()->record_update_rs_time(worker_i, (os::elapsedTime() - start) * 1000.0); ysr@777: } ysr@777: johnc@2216: void G1RemSet::cleanupHRRS() { ysr@777: HeapRegionRemSet::cleanup(); ysr@777: } ysr@777: mgerdin@7971: void G1RemSet::oops_into_collection_set_do(G1ParPushHeapRSClosure* oc, mgerdin@7208: CodeBlobClosure* code_root_cl, vkempik@6552: uint worker_i) { ysr@777: #if CARD_REPEAT_HISTO ysr@777: ct_freq_update_histo_and_reset(); ysr@777: #endif ysr@777: johnc@2060: // We cache the value of 'oc' closure into the appropriate slot in the johnc@2060: // _cset_rs_update_cl for this worker vkempik@6552: assert(worker_i < n_workers(), "sanity"); johnc@2060: _cset_rs_update_cl[worker_i] = oc; johnc@2060: johnc@2060: // A DirtyCardQueue that is used to hold cards containing references johnc@2060: // that point into the collection set. This DCQ is associated with a johnc@2060: // special DirtyCardQueueSet (see g1CollectedHeap.hpp). Under normal johnc@2060: // circumstances (i.e. the pause successfully completes), these cards johnc@2060: // are just discarded (there's no need to update the RSets of regions johnc@2060: // that were in the collection set - after the pause these regions johnc@2060: // are wholly 'free' of live objects. In the event of an evacuation tschatzl@7218: // failure the cards/buffers in this queue set are passed to the tschatzl@7218: // DirtyCardQueueSet that is used to manage RSet updates johnc@2060: DirtyCardQueue into_cset_dcq(&_g1->into_cset_dirty_card_queue_set()); johnc@2060: johnc@2063: assert((ParallelGCThreads > 0) || worker_i == 0, "invariant"); johnc@2063: johnc@2063: // The two flags below were introduced temporarily to serialize johnc@2063: // the updating and scanning of remembered sets. There are some johnc@2063: // race conditions when these two operations are done in parallel johnc@2063: // and they are causing failures. When we resolve said race johnc@2063: // conditions, we'll revert back to parallel remembered set johnc@2063: // updating and scanning. See CRs 6677707 and 6677708. johnc@2063: if (G1UseParallelRSetUpdating || (worker_i == 0)) { johnc@2063: updateRS(&into_cset_dcq, worker_i); ysr@777: } else { brutisso@4015: _g1p->phase_times()->record_update_rs_processed_buffers(worker_i, 0); brutisso@3923: _g1p->phase_times()->record_update_rs_time(worker_i, 0.0); johnc@2063: } johnc@2063: if (G1UseParallelRSetScanning || (worker_i == 0)) { johnc@5548: scanRS(oc, code_root_cl, worker_i); johnc@2063: } else { brutisso@3923: _g1p->phase_times()->record_scan_rs_time(worker_i, 0.0); ysr@777: } johnc@2060: johnc@2060: // We now clear the cached values of _cset_rs_update_cl for this worker johnc@2060: _cset_rs_update_cl[worker_i] = NULL; ysr@777: } ysr@777: johnc@2216: void G1RemSet::prepare_for_oops_into_collection_set_do() { ysr@777: cleanupHRRS(); ysr@777: _g1->set_refine_cte_cl_concurrency(false); ysr@777: DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set(); ysr@777: dcqs.concatenate_logs(); ysr@777: ysr@777: guarantee( _cards_scanned == NULL, "invariant" ); zgu@3900: _cards_scanned = NEW_C_HEAP_ARRAY(size_t, n_workers(), mtGC); apetrusenko@980: for (uint i = 0; i < n_workers(); ++i) { apetrusenko@980: _cards_scanned[i] = 0; apetrusenko@980: } ysr@777: _total_cards_scanned = 0; ysr@777: } ysr@777: johnc@2216: void G1RemSet::cleanup_after_oops_into_collection_set_do() { ysr@777: guarantee( _cards_scanned != NULL, "invariant" ); ysr@777: _total_cards_scanned = 0; tonyp@2974: for (uint i = 0; i < n_workers(); ++i) { ysr@777: _total_cards_scanned += _cards_scanned[i]; tonyp@2974: } zgu@3900: FREE_C_HEAP_ARRAY(size_t, _cards_scanned, mtGC); ysr@777: _cards_scanned = NULL; ysr@777: // Cleanup after copy ysr@777: _g1->set_refine_cte_cl_concurrency(true); ysr@777: // Set all cards back to clean. ysr@777: _g1->cleanUpCardTable(); iveresov@1229: johnc@2060: DirtyCardQueueSet& into_cset_dcqs = _g1->into_cset_dirty_card_queue_set(); johnc@2060: int into_cset_n_buffers = into_cset_dcqs.completed_buffers_num(); johnc@2060: iveresov@1051: if (_g1->evacuation_failed()) { tschatzl@6406: double restore_remembered_set_start = os::elapsedTime(); tschatzl@6406: johnc@2060: // Restore remembered sets for the regions pointing into the collection set. tschatzl@7218: // We just need to transfer the completed buffers from the DirtyCardQueueSet tschatzl@7218: // used to hold cards that contain references that point into the collection set tschatzl@7218: // to the DCQS used to hold the deferred RS updates. tschatzl@7218: _g1->dirty_card_queue_set().merge_bufferlists(&into_cset_dcqs); tschatzl@6406: _g1->g1_policy()->phase_times()->record_evac_fail_restore_remsets((os::elapsedTime() - restore_remembered_set_start) * 1000.0); iveresov@1051: } johnc@2060: johnc@2060: // Free any completed buffers in the DirtyCardQueueSet used to hold cards johnc@2060: // which contain references that point into the collection. johnc@2060: _g1->into_cset_dirty_card_queue_set().clear(); johnc@2060: assert(_g1->into_cset_dirty_card_queue_set().completed_buffers_num() == 0, johnc@2060: "all buffers should be freed"); johnc@2060: _g1->into_cset_dirty_card_queue_set().clear_n_completed_buffers(); ysr@777: } ysr@777: ysr@777: class ScrubRSClosure: public HeapRegionClosure { ysr@777: G1CollectedHeap* _g1h; ysr@777: BitMap* _region_bm; ysr@777: BitMap* _card_bm; ysr@777: CardTableModRefBS* _ctbs; ysr@777: public: ysr@777: ScrubRSClosure(BitMap* region_bm, BitMap* card_bm) : ysr@777: _g1h(G1CollectedHeap::heap()), ysr@777: _region_bm(region_bm), _card_bm(card_bm), mgerdin@5811: _ctbs(_g1h->g1_barrier_set()) {} ysr@777: ysr@777: bool doHeapRegion(HeapRegion* r) { ysr@777: if (!r->continuesHumongous()) { ysr@777: r->rem_set()->scrub(_ctbs, _region_bm, _card_bm); ysr@777: } ysr@777: return false; ysr@777: } ysr@777: }; ysr@777: johnc@2216: void G1RemSet::scrub(BitMap* region_bm, BitMap* card_bm) { ysr@777: ScrubRSClosure scrub_cl(region_bm, card_bm); ysr@777: _g1->heap_region_iterate(&scrub_cl); ysr@777: } ysr@777: johnc@2216: void G1RemSet::scrub_par(BitMap* region_bm, BitMap* card_bm, jmasa@3357: uint worker_num, int claim_val) { ysr@777: ScrubRSClosure scrub_cl(region_bm, card_bm); jmasa@3294: _g1->heap_region_par_iterate_chunked(&scrub_cl, jmasa@3294: worker_num, jmasa@3357: n_workers(), jmasa@3294: claim_val); ysr@777: } ysr@777: johnc@3466: G1TriggerClosure::G1TriggerClosure() : johnc@3466: _triggered(false) { } johnc@2060: johnc@3466: G1InvokeIfNotTriggeredClosure::G1InvokeIfNotTriggeredClosure(G1TriggerClosure* t_cl, johnc@3466: OopClosure* oop_cl) : johnc@3466: _trigger_cl(t_cl), _oop_cl(oop_cl) { } johnc@3466: johnc@3466: G1Mux2Closure::G1Mux2Closure(OopClosure *c1, OopClosure *c2) : johnc@3466: _c1(c1), _c2(c2) { } johnc@3466: johnc@3466: G1UpdateRSOrPushRefOopClosure:: johnc@3466: G1UpdateRSOrPushRefOopClosure(G1CollectedHeap* g1h, johnc@3466: G1RemSet* rs, mgerdin@7971: G1ParPushHeapRSClosure* push_ref_cl, johnc@3466: bool record_refs_into_cset, vkempik@6552: uint worker_i) : johnc@3466: _g1(g1h), _g1_rem_set(rs), _from(NULL), johnc@3466: _record_refs_into_cset(record_refs_into_cset), johnc@3466: _push_ref_cl(push_ref_cl), _worker_i(worker_i) { } johnc@2060: johnc@5078: // Returns true if the given card contains references that point johnc@5078: // into the collection set, if we're checking for such references; johnc@5078: // false otherwise. johnc@5078: vkempik@6552: bool G1RemSet::refine_card(jbyte* card_ptr, uint worker_i, johnc@5078: bool check_for_refs_into_cset) { tschatzl@7051: assert(_g1->is_in_exact(_ct_bs->addr_for(card_ptr)), tschatzl@7051: err_msg("Card at "PTR_FORMAT" index "SIZE_FORMAT" representing heap at "PTR_FORMAT" (%u) must be in committed heap", tschatzl@7051: p2i(card_ptr), tschatzl@7051: _ct_bs->index_for(_ct_bs->addr_for(card_ptr)), tschatzl@7051: _ct_bs->addr_for(card_ptr), tschatzl@7051: _g1->addr_to_region(_ct_bs->addr_for(card_ptr)))); johnc@5078: johnc@5078: // If the card is no longer dirty, nothing to do. johnc@5078: if (*card_ptr != CardTableModRefBS::dirty_card_val()) { johnc@5078: // No need to return that this card contains refs that point johnc@5078: // into the collection set. johnc@5078: return false; johnc@5078: } johnc@5078: johnc@1325: // Construct the region representing the card. johnc@1325: HeapWord* start = _ct_bs->addr_for(card_ptr); johnc@1325: // And find the region containing it. johnc@1325: HeapRegion* r = _g1->heap_region_containing(start); johnc@5078: johnc@5078: // Why do we have to check here whether a card is on a young region, johnc@5078: // given that we dirty young regions and, as a result, the johnc@5078: // post-barrier is supposed to filter them out and never to enqueue johnc@5078: // them? When we allocate a new region as the "allocation region" we johnc@5078: // actually dirty its cards after we release the lock, since card johnc@5078: // dirtying while holding the lock was a performance bottleneck. So, johnc@5078: // as a result, it is possible for other threads to actually johnc@5078: // allocate objects in the region (after the acquire the lock) johnc@5078: // before all the cards on the region are dirtied. This is unlikely, johnc@5078: // and it doesn't happen often, but it can happen. So, the extra johnc@5078: // check below filters out those cards. johnc@5078: if (r->is_young()) { johnc@5078: return false; johnc@5078: } johnc@5078: johnc@5078: // While we are processing RSet buffers during the collection, we johnc@5078: // actually don't want to scan any cards on the collection set, johnc@5078: // since we don't want to update remebered sets with entries that johnc@5078: // point into the collection set, given that live objects from the johnc@5078: // collection set are about to move and such entries will be stale johnc@5078: // very soon. This change also deals with a reliability issue which johnc@5078: // involves scanning a card in the collection set and coming across johnc@5078: // an array that was being chunked and looking malformed. Note, johnc@5078: // however, that if evacuation fails, we have to scan any objects johnc@5078: // that were not moved and create any missing entries. johnc@5078: if (r->in_collection_set()) { johnc@5078: return false; johnc@5078: } johnc@5078: johnc@5078: // The result from the hot card cache insert call is either: johnc@5078: // * pointer to the current card johnc@5078: // (implying that the current card is not 'hot'), johnc@5078: // * null johnc@5078: // (meaning we had inserted the card ptr into the "hot" card cache, johnc@5078: // which had some headroom), johnc@5078: // * a pointer to a "hot" card that was evicted from the "hot" cache. johnc@5078: // johnc@5078: johnc@5078: G1HotCardCache* hot_card_cache = _cg1r->hot_card_cache(); johnc@5078: if (hot_card_cache->use_cache()) { johnc@5078: assert(!check_for_refs_into_cset, "sanity"); johnc@5078: assert(!SafepointSynchronize::is_at_safepoint(), "sanity"); johnc@5078: johnc@5078: card_ptr = hot_card_cache->insert(card_ptr); johnc@5078: if (card_ptr == NULL) { johnc@5078: // There was no eviction. Nothing to do. johnc@5078: return false; johnc@5078: } johnc@5078: johnc@5078: start = _ct_bs->addr_for(card_ptr); johnc@5078: r = _g1->heap_region_containing(start); johnc@5078: johnc@5078: // Checking whether the region we got back from the cache johnc@5078: // is young here is inappropriate. The region could have been johnc@5078: // freed, reallocated and tagged as young while in the cache. johnc@5078: // Hence we could see its young type change at any time. johnc@5078: } johnc@1325: coleenp@4037: // Don't use addr_for(card_ptr + 1) which can ask for coleenp@4037: // a card beyond the heap. This is not safe without a perm coleenp@4037: // gen at the upper end of the heap. coleenp@4037: HeapWord* end = start + CardTableModRefBS::card_size_in_words; johnc@1325: MemRegion dirtyRegion(start, end); johnc@1325: johnc@1325: #if CARD_REPEAT_HISTO johnc@2504: init_ct_freq_table(_g1->max_capacity()); johnc@1325: ct_freq_note_card(_ct_bs->index_for(start)); johnc@1325: #endif johnc@1325: mgerdin@7971: G1ParPushHeapRSClosure* oops_in_heap_closure = NULL; brutisso@3267: if (check_for_refs_into_cset) { brutisso@3267: // ConcurrentG1RefineThreads have worker numbers larger than what brutisso@3267: // _cset_rs_update_cl[] is set up to handle. But those threads should brutisso@3267: // only be active outside of a collection which means that when they brutisso@3267: // reach here they should have check_for_refs_into_cset == false. brutisso@3267: assert((size_t)worker_i < n_workers(), "index of worker larger than _cset_rs_update_cl[].length"); brutisso@3267: oops_in_heap_closure = _cset_rs_update_cl[worker_i]; brutisso@3267: } johnc@3466: G1UpdateRSOrPushRefOopClosure update_rs_oop_cl(_g1, johnc@3466: _g1->g1_rem_set(), johnc@3466: oops_in_heap_closure, johnc@3466: check_for_refs_into_cset, johnc@3466: worker_i); johnc@1325: update_rs_oop_cl.set_from(r); johnc@2060: johnc@3466: G1TriggerClosure trigger_cl; johnc@3179: FilterIntoCSClosure into_cs_cl(NULL, _g1, &trigger_cl); johnc@3466: G1InvokeIfNotTriggeredClosure invoke_cl(&trigger_cl, &into_cs_cl); johnc@3466: G1Mux2Closure mux(&invoke_cl, &update_rs_oop_cl); johnc@2060: johnc@2060: FilterOutOfRegionClosure filter_then_update_rs_oop_cl(r, johnc@2060: (check_for_refs_into_cset ? johnc@2060: (OopClosure*)&mux : johnc@2060: (OopClosure*)&update_rs_oop_cl)); johnc@1325: johnc@2021: // The region for the current card may be a young region. The johnc@2021: // current card may have been a card that was evicted from the johnc@2021: // card cache. When the card was inserted into the cache, we had johnc@2021: // determined that its region was non-young. While in the cache, johnc@2021: // the region may have been freed during a cleanup pause, reallocated johnc@2021: // and tagged as young. johnc@2021: // johnc@2021: // We wish to filter out cards for such a region but the current tonyp@2849: // thread, if we're running concurrently, may "see" the young type johnc@2021: // change at any time (so an earlier "is_young" check may pass or johnc@2021: // fail arbitrarily). We tell the iteration code to perform this johnc@2021: // filtering when it has been determined that there has been an actual johnc@2021: // allocation in this region and making it safe to check the young type. johnc@2021: bool filter_young = true; johnc@2021: johnc@1325: HeapWord* stop_point = johnc@1325: r->oops_on_card_seq_iterate_careful(dirtyRegion, johnc@2021: &filter_then_update_rs_oop_cl, tonyp@2849: filter_young, tonyp@2849: card_ptr); johnc@2021: johnc@1325: // If stop_point is non-null, then we encountered an unallocated region johnc@1325: // (perhaps the unfilled portion of a TLAB.) For now, we'll dirty the johnc@1325: // card and re-enqueue: if we put off the card until a GC pause, then the johnc@1325: // unallocated portion will be filled in. Alternatively, we might try johnc@1325: // the full complexity of the technique used in "regular" precleaning. johnc@1325: if (stop_point != NULL) { johnc@1325: // The card might have gotten re-dirtied and re-enqueued while we johnc@1325: // worked. (In fact, it's pretty likely.) johnc@1325: if (*card_ptr != CardTableModRefBS::dirty_card_val()) { johnc@1325: *card_ptr = CardTableModRefBS::dirty_card_val(); johnc@1325: MutexLockerEx x(Shared_DirtyCardQ_lock, johnc@1325: Mutex::_no_safepoint_check_flag); johnc@1325: DirtyCardQueue* sdcq = johnc@1325: JavaThread::dirty_card_queue_set().shared_dirty_card_queue(); johnc@1325: sdcq->enqueue(card_ptr); johnc@1325: } johnc@1325: } else { johnc@1325: _conc_refine_cards++; johnc@1325: } johnc@2060: johnc@5078: // This gets set to true if the card being refined has johnc@5078: // references that point into the collection set. johnc@5078: bool has_refs_into_cset = trigger_cl.triggered(); johnc@1325: johnc@5078: // We should only be detecting that the card contains references johnc@5078: // that point into the collection set if the current thread is johnc@5078: // a GC worker thread. johnc@5078: assert(!has_refs_into_cset || SafepointSynchronize::is_at_safepoint(), johnc@5078: "invalid result at non safepoint"); ysr@777: johnc@5078: return has_refs_into_cset; ysr@777: } ysr@777: tschatzl@5807: void G1RemSet::print_periodic_summary_info(const char* header) { tschatzl@5204: G1RemSetSummary current; tschatzl@5812: current.initialize(this); ysr@777: tschatzl@5204: _prev_period_summary.subtract_from(¤t); tschatzl@5807: print_summary_info(&_prev_period_summary, header); ysr@777: tschatzl@5204: _prev_period_summary.set(¤t); tschatzl@5204: } iveresov@1229: johnc@2216: void G1RemSet::print_summary_info() { tschatzl@5204: G1RemSetSummary current; tschatzl@5812: current.initialize(this); tschatzl@5204: tschatzl@5204: print_summary_info(¤t, " Cumulative RS summary"); tschatzl@5204: } tschatzl@5204: tschatzl@5204: void G1RemSet::print_summary_info(G1RemSetSummary * summary, const char * header) { tschatzl@5204: assert(summary != NULL, "just checking"); tschatzl@5204: tschatzl@5204: if (header != NULL) { tschatzl@5204: gclog_or_tty->print_cr("%s", header); tschatzl@5204: } ysr@777: ysr@777: #if CARD_REPEAT_HISTO ysr@777: gclog_or_tty->print_cr("\nG1 card_repeat count histogram: "); ysr@777: gclog_or_tty->print_cr(" # of repeats --> # of cards with that number."); ysr@777: card_repeat_count.print_on(gclog_or_tty); ysr@777: #endif ysr@777: tschatzl@5204: summary->print_on(gclog_or_tty); ysr@777: } johnc@2060: johnc@2216: void G1RemSet::prepare_for_verify() { iveresov@1072: if (G1HRRSFlushLogBuffersOnVerify && iveresov@1072: (VerifyBeforeGC || VerifyAfterGC) johnc@5205: && (!_g1->full_collection() || G1VerifyRSetsDuringFullGC)) { ysr@777: cleanupHRRS(); ysr@777: _g1->set_refine_cte_cl_concurrency(false); ysr@777: if (SafepointSynchronize::is_at_safepoint()) { ysr@777: DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set(); ysr@777: dcqs.concatenate_logs(); ysr@777: } johnc@5078: johnc@5078: G1HotCardCache* hot_card_cache = _cg1r->hot_card_cache(); johnc@5078: bool use_hot_card_cache = hot_card_cache->use_cache(); johnc@5078: hot_card_cache->set_use_cache(false); johnc@5078: johnc@2060: DirtyCardQueue into_cset_dcq(&_g1->into_cset_dirty_card_queue_set()); johnc@2060: updateRS(&into_cset_dcq, 0); johnc@2060: _g1->into_cset_dirty_card_queue_set().clear(); iveresov@1072: johnc@5078: hot_card_cache->set_use_cache(use_hot_card_cache); iveresov@1072: assert(JavaThread::dirty_card_queue_set().completed_buffers_num() == 0, "All should be consumed"); ysr@777: } ysr@777: }