ysr@777: /* johnc@4929: * Copyright (c) 2001, 2013, 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: #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTORPOLICY_HPP stefank@2314: #define SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTORPOLICY_HPP stefank@2314: stefank@2314: #include "gc_implementation/g1/collectionSetChooser.hpp" stefank@2314: #include "gc_implementation/g1/g1MMUTracker.hpp" stefank@2314: #include "memory/collectorPolicy.hpp" stefank@2314: ysr@777: // A G1CollectorPolicy makes policy decisions that determine the ysr@777: // characteristics of the collector. Examples include: ysr@777: // * choice of collection set. ysr@777: // * when to collect. ysr@777: ysr@777: class HeapRegion; ysr@777: class CollectionSetChooser; brutisso@3923: class G1GCPhaseTimes; ysr@777: brutisso@3812: // TraceGen0Time collects data on _both_ young and mixed evacuation pauses brutisso@3812: // (the latter may contain non-young regions - i.e. regions that are brutisso@3812: // technically in Gen1) while TraceGen1Time collects data about full GCs. zgu@3900: class TraceGen0TimeData : public CHeapObj { brutisso@3812: private: brutisso@3812: unsigned _young_pause_num; brutisso@3812: unsigned _mixed_pause_num; ysr@777: brutisso@3812: NumberSeq _all_stop_world_times_ms; brutisso@3812: NumberSeq _all_yield_times_ms; ysr@777: brutisso@3812: NumberSeq _total; brutisso@3812: NumberSeq _other; brutisso@3812: NumberSeq _root_region_scan_wait; brutisso@3812: NumberSeq _parallel; brutisso@3812: NumberSeq _ext_root_scan; brutisso@3812: NumberSeq _satb_filtering; brutisso@3812: NumberSeq _update_rs; brutisso@3812: NumberSeq _scan_rs; brutisso@3812: NumberSeq _obj_copy; brutisso@3812: NumberSeq _termination; brutisso@3812: NumberSeq _parallel_other; brutisso@3812: NumberSeq _clear_ct; ysr@777: brutisso@3923: void print_summary(const char* str, const NumberSeq* seq) const; brutisso@3923: void print_summary_sd(const char* str, const NumberSeq* seq) const; ysr@777: ysr@777: public: brutisso@3812: TraceGen0TimeData() : _young_pause_num(0), _mixed_pause_num(0) {}; brutisso@3812: void record_start_collection(double time_to_stop_the_world_ms); brutisso@3812: void record_yield_time(double yield_time_ms); brutisso@3923: void record_end_collection(double pause_time_ms, G1GCPhaseTimes* phase_times); brutisso@3812: void increment_young_collection_count(); brutisso@3812: void increment_mixed_collection_count(); brutisso@3812: void print() const; ysr@777: }; ysr@777: zgu@3900: class TraceGen1TimeData : public CHeapObj { brutisso@3812: private: brutisso@3812: NumberSeq _all_full_gc_times; ysr@777: brutisso@3812: public: brutisso@3812: void record_full_collection(double full_gc_time_ms); brutisso@3812: void print() const; ysr@777: }; ysr@777: brutisso@3358: // There are three command line options related to the young gen size: brutisso@3358: // NewSize, MaxNewSize and NewRatio (There is also -Xmn, but that is brutisso@3358: // just a short form for NewSize==MaxNewSize). G1 will use its internal brutisso@3358: // heuristics to calculate the actual young gen size, so these options brutisso@3358: // basically only limit the range within which G1 can pick a young gen brutisso@3358: // size. Also, these are general options taking byte sizes. G1 will brutisso@3358: // internally work with a number of regions instead. So, some rounding brutisso@3358: // will occur. brutisso@3358: // brutisso@3358: // If nothing related to the the young gen size is set on the command johnc@4385: // line we should allow the young gen to be between G1NewSizePercent johnc@4385: // and G1MaxNewSizePercent of the heap size. This means that every time johnc@4385: // the heap size changes, the limits for the young gen size will be johnc@4385: // recalculated. brutisso@3358: // brutisso@3358: // If only -XX:NewSize is set we should use the specified value as the johnc@4385: // minimum size for young gen. Still using G1MaxNewSizePercent of the johnc@4385: // heap as maximum. brutisso@3358: // brutisso@3358: // If only -XX:MaxNewSize is set we should use the specified value as the johnc@4385: // maximum size for young gen. Still using G1NewSizePercent of the heap johnc@4385: // as minimum. brutisso@3358: // brutisso@3358: // If -XX:NewSize and -XX:MaxNewSize are both specified we use these values. brutisso@3358: // No updates when the heap size changes. There is a special case when brutisso@3358: // NewSize==MaxNewSize. This is interpreted as "fixed" and will use a brutisso@3358: // different heuristic for calculating the collection set when we do mixed brutisso@3358: // collection. brutisso@3358: // brutisso@3358: // If only -XX:NewRatio is set we should use the specified ratio of the heap brutisso@3358: // as both min and max. This will be interpreted as "fixed" just like the brutisso@3358: // NewSize==MaxNewSize case above. But we will update the min and max brutisso@3358: // everytime the heap size changes. brutisso@3358: // brutisso@3358: // NewSize and MaxNewSize override NewRatio. So, NewRatio is ignored if it is brutisso@3358: // combined with either NewSize or MaxNewSize. (A warning message is printed.) zgu@3900: class G1YoungGenSizer : public CHeapObj { brutisso@3358: private: brutisso@3358: enum SizerKind { brutisso@3358: SizerDefaults, brutisso@3358: SizerNewSizeOnly, brutisso@3358: SizerMaxNewSizeOnly, brutisso@3358: SizerMaxAndNewSize, brutisso@3358: SizerNewRatio brutisso@3358: }; brutisso@3358: SizerKind _sizer_kind; tonyp@3713: uint _min_desired_young_length; tonyp@3713: uint _max_desired_young_length; brutisso@3358: bool _adaptive_size; tonyp@3713: uint calculate_default_min_length(uint new_number_of_heap_regions); tonyp@3713: uint calculate_default_max_length(uint new_number_of_heap_regions); brutisso@3358: jwilhelm@6085: // Update the given values for minimum and maximum young gen length in regions jwilhelm@6085: // given the number of heap regions depending on the kind of sizing algorithm. jwilhelm@6085: void recalculate_min_max_young_length(uint number_of_heap_regions, uint* min_young_length, uint* max_young_length); jwilhelm@6085: brutisso@3358: public: brutisso@3358: G1YoungGenSizer(); jwilhelm@6085: // Calculate the maximum length of the young gen given the number of regions jwilhelm@6085: // depending on the sizing algorithm. jwilhelm@6085: uint max_young_length(uint number_of_heap_regions); jwilhelm@6085: tonyp@3713: void heap_size_changed(uint new_number_of_heap_regions); tonyp@3713: uint min_desired_young_length() { brutisso@3358: return _min_desired_young_length; brutisso@3358: } tonyp@3713: uint max_desired_young_length() { brutisso@3358: return _max_desired_young_length; brutisso@3358: } brutisso@3358: bool adaptive_young_list_length() { brutisso@3358: return _adaptive_size; brutisso@3358: } brutisso@3358: }; brutisso@3358: ysr@777: class G1CollectorPolicy: public CollectorPolicy { tonyp@3209: private: ysr@777: // either equal to the number of parallel threads, if ParallelGCThreads ysr@777: // has been set, or 1 otherwise ysr@777: int _parallel_gc_threads; ysr@777: jmasa@3294: // The number of GC threads currently active. jmasa@3294: uintx _no_of_gc_threads; jmasa@3294: ysr@777: enum SomePrivateConstants { tonyp@1377: NumPrevPausesForHeuristics = 10 ysr@777: }; ysr@777: ysr@777: G1MMUTracker* _mmu_tracker; ysr@777: jwilhelm@6085: void initialize_alignments(); ysr@777: void initialize_flags(); ysr@777: tonyp@3209: CollectionSetChooser* _collectionSetChooser; ysr@777: brutisso@3923: double _full_collection_start_sec; tonyp@3713: uint _cur_collection_pause_used_regions_at_start; johnc@1325: ysr@777: // These exclude marking times. ysr@777: TruncatedSeq* _recent_gc_times_ms; ysr@777: ysr@777: TruncatedSeq* _concurrent_mark_remark_times_ms; ysr@777: TruncatedSeq* _concurrent_mark_cleanup_times_ms; ysr@777: brutisso@3812: TraceGen0TimeData _trace_gen0_time_data; brutisso@3812: TraceGen1TimeData _trace_gen1_time_data; ysr@777: ysr@777: double _stop_world_start; ysr@777: tonyp@3337: // indicates whether we are in young or mixed GC mode tonyp@3337: bool _gcs_are_young; ysr@777: tonyp@3713: uint _young_list_target_length; tonyp@3713: uint _young_list_fixed_length; ysr@777: tonyp@2333: // The max number of regions we can extend the eden by while the GC tonyp@2333: // locker is active. This should be >= _young_list_target_length; tonyp@3713: uint _young_list_max_length; tonyp@2333: tonyp@3337: bool _last_gc_was_young; ysr@777: ysr@777: bool _during_marking; ysr@777: bool _in_marking_window; ysr@777: bool _in_marking_window_im; ysr@777: ysr@777: SurvRateGroup* _short_lived_surv_rate_group; ysr@777: SurvRateGroup* _survivor_surv_rate_group; ysr@777: // add here any more surv rate groups ysr@777: tonyp@1791: double _gc_overhead_perc; tonyp@1791: tonyp@3119: double _reserve_factor; tonyp@3713: uint _reserve_regions; tonyp@3119: ysr@777: bool during_marking() { ysr@777: return _during_marking; ysr@777: } ysr@777: ysr@777: enum PredictionConstants { ysr@777: TruncatedSeqLength = 10 ysr@777: }; ysr@777: ysr@777: TruncatedSeq* _alloc_rate_ms_seq; ysr@777: double _prev_collection_pause_end_ms; ysr@777: ysr@777: TruncatedSeq* _rs_length_diff_seq; ysr@777: TruncatedSeq* _cost_per_card_ms_seq; tonyp@3337: TruncatedSeq* _young_cards_per_entry_ratio_seq; tonyp@3337: TruncatedSeq* _mixed_cards_per_entry_ratio_seq; ysr@777: TruncatedSeq* _cost_per_entry_ms_seq; tonyp@3337: TruncatedSeq* _mixed_cost_per_entry_ms_seq; ysr@777: TruncatedSeq* _cost_per_byte_ms_seq; ysr@777: TruncatedSeq* _constant_other_time_ms_seq; ysr@777: TruncatedSeq* _young_other_cost_per_region_ms_seq; ysr@777: TruncatedSeq* _non_young_other_cost_per_region_ms_seq; ysr@777: ysr@777: TruncatedSeq* _pending_cards_seq; ysr@777: TruncatedSeq* _rs_lengths_seq; ysr@777: ysr@777: TruncatedSeq* _cost_per_byte_ms_during_cm_seq; ysr@777: brutisso@3358: G1YoungGenSizer* _young_gen_sizer; brutisso@3120: tonyp@3713: uint _eden_cset_region_length; tonyp@3713: uint _survivor_cset_region_length; tonyp@3713: uint _old_cset_region_length; tonyp@3289: tonyp@3713: void init_cset_region_lengths(uint eden_cset_region_length, tonyp@3713: uint survivor_cset_region_length); tonyp@3289: tonyp@3713: uint eden_cset_region_length() { return _eden_cset_region_length; } tonyp@3713: uint survivor_cset_region_length() { return _survivor_cset_region_length; } tonyp@3713: uint old_cset_region_length() { return _old_cset_region_length; } ysr@777: tonyp@3713: uint _free_regions_at_end_of_collection; ysr@777: ysr@777: size_t _recorded_rs_lengths; ysr@777: size_t _max_rs_lengths; ysr@777: double _sigma; ysr@777: ysr@777: size_t _rs_lengths_prediction; ysr@777: tonyp@3539: double sigma() { return _sigma; } ysr@777: ysr@777: // A function that prevents us putting too much stock in small sample ysr@777: // sets. Returns a number between 2.0 and 1.0, depending on the number ysr@777: // of samples. 5 or more samples yields one; fewer scales linearly from ysr@777: // 2.0 at 1 sample to 1.0 at 5. ysr@777: double confidence_factor(int samples) { ysr@777: if (samples > 4) return 1.0; ysr@777: else return 1.0 + sigma() * ((double)(5 - samples))/2.0; ysr@777: } ysr@777: ysr@777: double get_new_neg_prediction(TruncatedSeq* seq) { ysr@777: return seq->davg() - sigma() * seq->dsd(); ysr@777: } ysr@777: ysr@777: #ifndef PRODUCT ysr@777: bool verify_young_ages(HeapRegion* head, SurvRateGroup *surv_rate_group); ysr@777: #endif // PRODUCT ysr@777: iveresov@1546: void adjust_concurrent_refinement(double update_rs_time, iveresov@1546: double update_rs_processed_buffers, iveresov@1546: double goal_ms); iveresov@1546: jmasa@3294: uintx no_of_gc_threads() { return _no_of_gc_threads; } jmasa@3294: void set_no_of_gc_threads(uintx v) { _no_of_gc_threads = v; } jmasa@3294: ysr@777: double _pause_time_target_ms; brutisso@3923: ysr@777: size_t _pending_cards; ysr@777: ysr@777: public: jmasa@3294: // Accessors ysr@777: tonyp@3289: void set_region_eden(HeapRegion* hr, int young_index_in_cset) { tonyp@3289: hr->set_young(); ysr@777: hr->install_surv_rate_group(_short_lived_surv_rate_group); tonyp@3289: hr->set_young_index_in_cset(young_index_in_cset); ysr@777: } ysr@777: tonyp@3289: void set_region_survivor(HeapRegion* hr, int young_index_in_cset) { tonyp@3289: assert(hr->is_young() && hr->is_survivor(), "pre-condition"); ysr@777: hr->install_surv_rate_group(_survivor_surv_rate_group); tonyp@3289: hr->set_young_index_in_cset(young_index_in_cset); ysr@777: } ysr@777: ysr@777: #ifndef PRODUCT ysr@777: bool verify_young_ages(); ysr@777: #endif // PRODUCT ysr@777: ysr@777: double get_new_prediction(TruncatedSeq* seq) { ysr@777: return MAX2(seq->davg() + sigma() * seq->dsd(), ysr@777: seq->davg() * confidence_factor(seq->num())); ysr@777: } ysr@777: ysr@777: void record_max_rs_lengths(size_t rs_lengths) { ysr@777: _max_rs_lengths = rs_lengths; ysr@777: } ysr@777: ysr@777: size_t predict_rs_length_diff() { ysr@777: return (size_t) get_new_prediction(_rs_length_diff_seq); ysr@777: } ysr@777: ysr@777: double predict_alloc_rate_ms() { ysr@777: return get_new_prediction(_alloc_rate_ms_seq); ysr@777: } ysr@777: ysr@777: double predict_cost_per_card_ms() { ysr@777: return get_new_prediction(_cost_per_card_ms_seq); ysr@777: } ysr@777: ysr@777: double predict_rs_update_time_ms(size_t pending_cards) { ysr@777: return (double) pending_cards * predict_cost_per_card_ms(); ysr@777: } ysr@777: tonyp@3337: double predict_young_cards_per_entry_ratio() { tonyp@3337: return get_new_prediction(_young_cards_per_entry_ratio_seq); ysr@777: } ysr@777: tonyp@3337: double predict_mixed_cards_per_entry_ratio() { tonyp@3337: if (_mixed_cards_per_entry_ratio_seq->num() < 2) { tonyp@3337: return predict_young_cards_per_entry_ratio(); tonyp@3337: } else { tonyp@3337: return get_new_prediction(_mixed_cards_per_entry_ratio_seq); tonyp@3337: } ysr@777: } ysr@777: ysr@777: size_t predict_young_card_num(size_t rs_length) { ysr@777: return (size_t) ((double) rs_length * tonyp@3337: predict_young_cards_per_entry_ratio()); ysr@777: } ysr@777: ysr@777: size_t predict_non_young_card_num(size_t rs_length) { ysr@777: return (size_t) ((double) rs_length * tonyp@3337: predict_mixed_cards_per_entry_ratio()); ysr@777: } ysr@777: ysr@777: double predict_rs_scan_time_ms(size_t card_num) { tonyp@3337: if (gcs_are_young()) { ysr@777: return (double) card_num * get_new_prediction(_cost_per_entry_ms_seq); tonyp@3337: } else { tonyp@3337: return predict_mixed_rs_scan_time_ms(card_num); tonyp@3337: } ysr@777: } ysr@777: tonyp@3337: double predict_mixed_rs_scan_time_ms(size_t card_num) { tonyp@3337: if (_mixed_cost_per_entry_ms_seq->num() < 3) { ysr@777: return (double) card_num * get_new_prediction(_cost_per_entry_ms_seq); tonyp@3337: } else { tonyp@3337: return (double) (card_num * tonyp@3337: get_new_prediction(_mixed_cost_per_entry_ms_seq)); tonyp@3337: } ysr@777: } ysr@777: ysr@777: double predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) { tonyp@3337: if (_cost_per_byte_ms_during_cm_seq->num() < 3) { tonyp@3337: return (1.1 * (double) bytes_to_copy) * tonyp@3337: get_new_prediction(_cost_per_byte_ms_seq); tonyp@3337: } else { ysr@777: return (double) bytes_to_copy * tonyp@3337: get_new_prediction(_cost_per_byte_ms_during_cm_seq); tonyp@3337: } ysr@777: } ysr@777: ysr@777: double predict_object_copy_time_ms(size_t bytes_to_copy) { tonyp@3337: if (_in_marking_window && !_in_marking_window_im) { ysr@777: return predict_object_copy_time_ms_during_cm(bytes_to_copy); tonyp@3337: } else { ysr@777: return (double) bytes_to_copy * tonyp@3337: get_new_prediction(_cost_per_byte_ms_seq); tonyp@3337: } ysr@777: } ysr@777: ysr@777: double predict_constant_other_time_ms() { ysr@777: return get_new_prediction(_constant_other_time_ms_seq); ysr@777: } ysr@777: ysr@777: double predict_young_other_time_ms(size_t young_num) { tonyp@3337: return (double) young_num * tonyp@3337: get_new_prediction(_young_other_cost_per_region_ms_seq); ysr@777: } ysr@777: ysr@777: double predict_non_young_other_time_ms(size_t non_young_num) { tonyp@3337: return (double) non_young_num * tonyp@3337: get_new_prediction(_non_young_other_cost_per_region_ms_seq); ysr@777: } ysr@777: ysr@777: double predict_base_elapsed_time_ms(size_t pending_cards); ysr@777: double predict_base_elapsed_time_ms(size_t pending_cards, ysr@777: size_t scanned_cards); ysr@777: size_t predict_bytes_to_copy(HeapRegion* hr); johnc@3998: double predict_region_elapsed_time_ms(HeapRegion* hr, bool for_young_gc); ysr@777: tonyp@3289: void set_recorded_rs_lengths(size_t rs_lengths); johnc@1829: tonyp@3713: uint cset_region_length() { return young_cset_region_length() + tonyp@3713: old_cset_region_length(); } tonyp@3713: uint young_cset_region_length() { return eden_cset_region_length() + tonyp@3713: survivor_cset_region_length(); } ysr@777: apetrusenko@980: double predict_survivor_regions_evac_time(); apetrusenko@980: ysr@777: void cset_regions_freed() { tonyp@3337: bool propagate = _last_gc_was_young && !_in_marking_window; ysr@777: _short_lived_surv_rate_group->all_surviving_words_recorded(propagate); ysr@777: _survivor_surv_rate_group->all_surviving_words_recorded(propagate); ysr@777: // also call it on any more surv rate groups ysr@777: } ysr@777: ysr@777: G1MMUTracker* mmu_tracker() { ysr@777: return _mmu_tracker; ysr@777: } ysr@777: tonyp@2011: double max_pause_time_ms() { tonyp@2011: return _mmu_tracker->max_gc_time() * 1000.0; tonyp@2011: } tonyp@2011: ysr@777: double predict_remark_time_ms() { ysr@777: return get_new_prediction(_concurrent_mark_remark_times_ms); ysr@777: } ysr@777: ysr@777: double predict_cleanup_time_ms() { ysr@777: return get_new_prediction(_concurrent_mark_cleanup_times_ms); ysr@777: } ysr@777: ysr@777: // Returns an estimate of the survival rate of the region at yg-age ysr@777: // "yg_age". apetrusenko@980: double predict_yg_surv_rate(int age, SurvRateGroup* surv_rate_group) { apetrusenko@980: TruncatedSeq* seq = surv_rate_group->get_seq(age); ysr@777: if (seq->num() == 0) ysr@777: gclog_or_tty->print("BARF! age is %d", age); ysr@777: guarantee( seq->num() > 0, "invariant" ); ysr@777: double pred = get_new_prediction(seq); ysr@777: if (pred > 1.0) ysr@777: pred = 1.0; ysr@777: return pred; ysr@777: } ysr@777: apetrusenko@980: double predict_yg_surv_rate(int age) { apetrusenko@980: return predict_yg_surv_rate(age, _short_lived_surv_rate_group); apetrusenko@980: } apetrusenko@980: ysr@777: double accum_yg_surv_rate_pred(int age) { ysr@777: return _short_lived_surv_rate_group->accum_surv_rate_pred(age); ysr@777: } ysr@777: tonyp@3209: private: ysr@777: // Statistics kept per GC stoppage, pause or full. ysr@777: TruncatedSeq* _recent_prev_end_times_for_all_gcs_sec; ysr@777: ysr@777: // Add a new GC of the given duration and end time to the record. ysr@777: void update_recent_gc_times(double end_time_sec, double elapsed_ms); ysr@777: ysr@777: // The head of the list (via "next_in_collection_set()") representing the johnc@1829: // current collection set. Set from the incrementally built collection johnc@1829: // set at the start of the pause. ysr@777: HeapRegion* _collection_set; johnc@1829: johnc@1829: // The number of bytes in the collection set before the pause. Set from johnc@1829: // the incrementally built collection set at the start of an evacuation johnc@3998: // pause, and incremented in finalize_cset() when adding old regions johnc@3998: // (if any) to the collection set. ysr@777: size_t _collection_set_bytes_used_before; ysr@777: johnc@3998: // The number of bytes copied during the GC. johnc@3998: size_t _bytes_copied_during_gc; johnc@3998: johnc@1829: // The associated information that is maintained while the incremental johnc@1829: // collection set is being built with young regions. Used to populate johnc@1829: // the recorded info for the evacuation pause. johnc@1829: johnc@1829: enum CSetBuildType { johnc@1829: Active, // We are actively building the collection set johnc@1829: Inactive // We are not actively building the collection set johnc@1829: }; johnc@1829: johnc@1829: CSetBuildType _inc_cset_build_state; johnc@1829: johnc@1829: // The head of the incrementally built collection set. johnc@1829: HeapRegion* _inc_cset_head; johnc@1829: johnc@1829: // The tail of the incrementally built collection set. johnc@1829: HeapRegion* _inc_cset_tail; johnc@1829: johnc@1829: // The number of bytes in the incrementally built collection set. johnc@1829: // Used to set _collection_set_bytes_used_before at the start of johnc@1829: // an evacuation pause. johnc@1829: size_t _inc_cset_bytes_used_before; johnc@1829: johnc@1829: // Used to record the highest end of heap region in collection set johnc@1829: HeapWord* _inc_cset_max_finger; johnc@1829: tonyp@3356: // The RSet lengths recorded for regions in the CSet. It is updated tonyp@3356: // by the thread that adds a new region to the CSet. We assume that tonyp@3356: // only one thread can be allocating a new CSet region (currently, tonyp@3356: // it does so after taking the Heap_lock) hence no need to tonyp@3356: // synchronize updates to this field. johnc@1829: size_t _inc_cset_recorded_rs_lengths; johnc@1829: tonyp@3356: // A concurrent refinement thread periodcially samples the young tonyp@3356: // region RSets and needs to update _inc_cset_recorded_rs_lengths as tonyp@3356: // the RSets grow. Instead of having to syncronize updates to that tonyp@3356: // field we accumulate them in this field and add it to tonyp@3356: // _inc_cset_recorded_rs_lengths_diffs at the start of a GC. tonyp@3356: ssize_t _inc_cset_recorded_rs_lengths_diffs; tonyp@3356: tonyp@3356: // The predicted elapsed time it will take to collect the regions in tonyp@3356: // the CSet. This is updated by the thread that adds a new region to tonyp@3356: // the CSet. See the comment for _inc_cset_recorded_rs_lengths about tonyp@3356: // MT-safety assumptions. johnc@1829: double _inc_cset_predicted_elapsed_time_ms; johnc@1829: tonyp@3356: // See the comment for _inc_cset_recorded_rs_lengths_diffs. tonyp@3356: double _inc_cset_predicted_elapsed_time_ms_diffs; tonyp@3356: ysr@777: // Stash a pointer to the g1 heap. ysr@777: G1CollectedHeap* _g1; ysr@777: brutisso@3923: G1GCPhaseTimes* _phase_times; brutisso@3923: ysr@777: // The ratio of gc time to elapsed time, computed over recent pauses. ysr@777: double _recent_avg_pause_time_ratio; ysr@777: ysr@777: double recent_avg_pause_time_ratio() { ysr@777: return _recent_avg_pause_time_ratio; ysr@777: } ysr@777: tonyp@1794: // At the end of a pause we check the heap occupancy and we decide tonyp@1794: // whether we will start a marking cycle during the next pause. If tonyp@1794: // we decide that we want to do that, we will set this parameter to tonyp@1794: // true. So, this parameter will stay true between the end of a tonyp@1794: // pause and the beginning of a subsequent pause (not necessarily tonyp@1794: // the next one, see the comments on the next field) when we decide tonyp@1794: // that we will indeed start a marking cycle and do the initial-mark tonyp@1794: // work. tonyp@1794: volatile bool _initiate_conc_mark_if_possible; ysr@777: tonyp@1794: // If initiate_conc_mark_if_possible() is set at the beginning of a tonyp@1794: // pause, it is a suggestion that the pause should start a marking tonyp@1794: // cycle by doing the initial-mark work. However, it is possible tonyp@1794: // that the concurrent marking thread is still finishing up the tonyp@1794: // previous marking cycle (e.g., clearing the next marking tonyp@1794: // bitmap). If that is the case we cannot start a new cycle and tonyp@1794: // we'll have to wait for the concurrent marking thread to finish tonyp@1794: // what it is doing. In this case we will postpone the marking cycle tonyp@1794: // initiation decision for the next pause. When we eventually decide tonyp@1794: // to start a cycle, we will set _during_initial_mark_pause which tonyp@1794: // will stay true until the end of the initial-mark pause and it's tonyp@1794: // the condition that indicates that a pause is doing the tonyp@1794: // initial-mark work. tonyp@1794: volatile bool _during_initial_mark_pause; tonyp@1794: tonyp@3337: bool _last_young_gc; ysr@777: ysr@777: // This set of variables tracks the collector efficiency, in order to ysr@777: // determine whether we should initiate a new marking. ysr@777: double _cur_mark_stop_world_time_ms; ysr@777: double _mark_remark_start_sec; ysr@777: double _mark_cleanup_start_sec; ysr@777: tonyp@3119: // Update the young list target length either by setting it to the tonyp@3119: // desired fixed value or by calculating it using G1's pause tonyp@3119: // prediction model. If no rs_lengths parameter is passed, predict tonyp@3119: // the RS lengths using the prediction model, otherwise use the tonyp@3119: // given rs_lengths as the prediction. tonyp@3119: void update_young_list_target_length(size_t rs_lengths = (size_t) -1); tonyp@3119: tonyp@3119: // Calculate and return the minimum desired young list target tonyp@3119: // length. This is the minimum desired young list length according tonyp@3119: // to the user's inputs. tonyp@3713: uint calculate_young_list_desired_min_length(uint base_min_length); tonyp@3119: tonyp@3119: // Calculate and return the maximum desired young list target tonyp@3119: // length. This is the maximum desired young list length according tonyp@3119: // to the user's inputs. tonyp@3713: uint calculate_young_list_desired_max_length(); tonyp@3119: tonyp@3119: // Calculate and return the maximum young list target length that tonyp@3119: // can fit into the pause time goal. The parameters are: rs_lengths tonyp@3119: // represent the prediction of how large the young RSet lengths will tonyp@3119: // be, base_min_length is the alreay existing number of regions in tonyp@3119: // the young list, min_length and max_length are the desired min and tonyp@3119: // max young list length according to the user's inputs. tonyp@3713: uint calculate_young_list_target_length(size_t rs_lengths, tonyp@3713: uint base_min_length, tonyp@3713: uint desired_min_length, tonyp@3713: uint desired_max_length); tonyp@3119: tonyp@3119: // Check whether a given young length (young_length) fits into the tonyp@3119: // given target pause time and whether the prediction for the amount tonyp@3119: // of objects to be copied for the given length will fit into the tonyp@3119: // given free space (expressed by base_free_regions). It is used by tonyp@3119: // calculate_young_list_target_length(). tonyp@3713: bool predict_will_fit(uint young_length, double base_time_ms, tonyp@3713: uint base_free_regions, double target_pause_time_ms); ysr@777: johnc@4681: // Calculate the minimum number of old regions we'll add to the CSet johnc@4681: // during a mixed GC. johnc@4681: uint calc_min_old_cset_length(); johnc@4681: johnc@4681: // Calculate the maximum number of old regions we'll add to the CSet johnc@4681: // during a mixed GC. johnc@4681: uint calc_max_old_cset_length(); johnc@4681: johnc@4681: // Returns the given amount of uncollected reclaimable space johnc@4681: // as a percentage of the current heap capacity. johnc@4681: double reclaimable_bytes_perc(size_t reclaimable_bytes); johnc@4681: ysr@777: public: ysr@777: ysr@777: G1CollectorPolicy(); ysr@777: ysr@777: virtual G1CollectorPolicy* as_g1_policy() { return this; } ysr@777: ysr@777: virtual CollectorPolicy::Name kind() { ysr@777: return CollectorPolicy::G1CollectorPolicyKind; ysr@777: } ysr@777: brutisso@3923: G1GCPhaseTimes* phase_times() const { return _phase_times; } brutisso@3923: tonyp@3119: // Check the current value of the young list RSet lengths and tonyp@3119: // compare it against the last prediction. If the current value is tonyp@3119: // higher, recalculate the young list target length prediction. tonyp@3119: void revise_young_list_target_length_if_necessary(); ysr@777: brutisso@3120: // This should be called after the heap is resized. tonyp@3713: void record_new_heap_size(uint new_number_of_regions); tonyp@3119: tonyp@3209: void init(); ysr@777: apetrusenko@980: // Create jstat counters for the policy. apetrusenko@980: virtual void initialize_gc_policy_counters(); apetrusenko@980: ysr@777: virtual HeapWord* mem_allocate_work(size_t size, ysr@777: bool is_tlab, ysr@777: bool* gc_overhead_limit_was_exceeded); ysr@777: ysr@777: // This method controls how a collector handles one or more ysr@777: // of its generations being fully allocated. ysr@777: virtual HeapWord* satisfy_failed_allocation(size_t size, ysr@777: bool is_tlab); ysr@777: ysr@777: BarrierSet::Name barrier_set_name() { return BarrierSet::G1SATBCTLogging; } ysr@777: brutisso@3461: bool need_to_start_conc_mark(const char* source, size_t alloc_word_size = 0); brutisso@3456: johnc@4929: // Record the start and end of an evacuation pause. johnc@4929: void record_collection_pause_start(double start_time_sec); sla@5237: void record_collection_pause_end(double pause_time_ms, EvacuationInfo& evacuation_info); ysr@777: johnc@4929: // Record the start and end of a full collection. johnc@4929: void record_full_collection_start(); johnc@4929: void record_full_collection_end(); ysr@777: ysr@777: // Must currently be called while the world is stopped. johnc@4929: void record_concurrent_mark_init_end(double mark_init_elapsed_time_ms); ysr@777: johnc@4929: // Record start and end of remark. tonyp@3209: void record_concurrent_mark_remark_start(); tonyp@3209: void record_concurrent_mark_remark_end(); ysr@777: johnc@4929: // Record start, end, and completion of cleanup. tonyp@3209: void record_concurrent_mark_cleanup_start(); jmasa@3294: void record_concurrent_mark_cleanup_end(int no_of_gc_threads); tonyp@3209: void record_concurrent_mark_cleanup_completed(); ysr@777: johnc@4929: // Records the information about the heap size for reporting in johnc@4929: // print_detailed_heap_transition johnc@5123: void record_heap_size_info_at_start(bool full); ysr@777: johnc@4929: // Print heap sizing transition (with less and more detail). tonyp@2961: void print_heap_transition(); johnc@5123: void print_detailed_heap_transition(bool full = false); ysr@777: johnc@4929: void record_stop_world_start(); johnc@4929: void record_concurrent_pause(); ysr@777: tonyp@3028: // Record how much space we copied during a GC. This is typically tonyp@3028: // called when a GC alloc region is being retired. tonyp@3028: void record_bytes_copied_during_gc(size_t bytes) { tonyp@3028: _bytes_copied_during_gc += bytes; tonyp@3028: } tonyp@3028: tonyp@3028: // The amount of space we copied during a GC. tonyp@3028: size_t bytes_copied_during_gc() { tonyp@3028: return _bytes_copied_during_gc; tonyp@3028: } ysr@777: brutisso@3675: // Determine whether there are candidate regions so that the brutisso@3675: // next GC should be mixed. The two action strings are used brutisso@3675: // in the ergo output when the method returns true or false. tonyp@3539: bool next_gc_should_be_mixed(const char* true_action_str, tonyp@3539: const char* false_action_str); tonyp@3539: ysr@777: // Choose a new collection set. Marks the chosen regions as being ysr@777: // "in_collection_set", and links them together. The head and number of ysr@777: // the collection set are available via access methods. sla@5237: void finalize_cset(double target_pause_time_ms, EvacuationInfo& evacuation_info); ysr@777: ysr@777: // The head of the list (via "next_in_collection_set()") representing the ysr@777: // current collection set. ysr@777: HeapRegion* collection_set() { return _collection_set; } ysr@777: johnc@1829: void clear_collection_set() { _collection_set = NULL; } johnc@1829: tonyp@3289: // Add old region "hr" to the CSet. tonyp@3289: void add_old_region_to_cset(HeapRegion* hr); ysr@777: johnc@1829: // Incremental CSet Support johnc@1829: johnc@1829: // The head of the incrementally built collection set. johnc@1829: HeapRegion* inc_cset_head() { return _inc_cset_head; } johnc@1829: johnc@1829: // The tail of the incrementally built collection set. johnc@1829: HeapRegion* inc_set_tail() { return _inc_cset_tail; } johnc@1829: johnc@1829: // Initialize incremental collection set info. johnc@1829: void start_incremental_cset_building(); johnc@1829: tonyp@3356: // Perform any final calculations on the incremental CSet fields tonyp@3356: // before we can use them. tonyp@3356: void finalize_incremental_cset_building(); tonyp@3356: johnc@1829: void clear_incremental_cset() { johnc@1829: _inc_cset_head = NULL; johnc@1829: _inc_cset_tail = NULL; johnc@1829: } johnc@1829: johnc@1829: // Stop adding regions to the incremental collection set johnc@1829: void stop_incremental_cset_building() { _inc_cset_build_state = Inactive; } johnc@1829: tonyp@3356: // Add information about hr to the aggregated information for the tonyp@3356: // incrementally built collection set. johnc@1829: void add_to_incremental_cset_info(HeapRegion* hr, size_t rs_length); johnc@1829: johnc@1829: // Update information about hr in the aggregated information for johnc@1829: // the incrementally built collection set. johnc@1829: void update_incremental_cset_info(HeapRegion* hr, size_t new_rs_length); johnc@1829: johnc@1829: private: johnc@1829: // Update the incremental cset information when adding a region johnc@1829: // (should not be called directly). johnc@1829: void add_region_to_incremental_cset_common(HeapRegion* hr); johnc@1829: johnc@1829: public: johnc@1829: // Add hr to the LHS of the incremental collection set. johnc@1829: void add_region_to_incremental_cset_lhs(HeapRegion* hr); johnc@1829: johnc@1829: // Add hr to the RHS of the incremental collection set. johnc@1829: void add_region_to_incremental_cset_rhs(HeapRegion* hr); johnc@1829: johnc@1829: #ifndef PRODUCT johnc@1829: void print_collection_set(HeapRegion* list_head, outputStream* st); johnc@1829: #endif // !PRODUCT johnc@1829: tonyp@1794: bool initiate_conc_mark_if_possible() { return _initiate_conc_mark_if_possible; } tonyp@1794: void set_initiate_conc_mark_if_possible() { _initiate_conc_mark_if_possible = true; } tonyp@1794: void clear_initiate_conc_mark_if_possible() { _initiate_conc_mark_if_possible = false; } tonyp@1794: tonyp@1794: bool during_initial_mark_pause() { return _during_initial_mark_pause; } tonyp@1794: void set_during_initial_mark_pause() { _during_initial_mark_pause = true; } tonyp@1794: void clear_during_initial_mark_pause(){ _during_initial_mark_pause = false; } tonyp@1794: tonyp@2011: // This sets the initiate_conc_mark_if_possible() flag to start a tonyp@2011: // new cycle, as long as we are not already in one. It's best if it tonyp@2011: // is called during a safepoint when the test whether a cycle is in tonyp@2011: // progress or not is stable. tonyp@3114: bool force_initial_mark_if_outside_cycle(GCCause::Cause gc_cause); tonyp@2011: tonyp@1794: // This is called at the very beginning of an evacuation pause (it tonyp@1794: // has to be the first thing that the pause does). If tonyp@1794: // initiate_conc_mark_if_possible() is true, and the concurrent tonyp@1794: // marking thread has completed its work during the previous cycle, tonyp@1794: // it will set during_initial_mark_pause() to so that the pause does tonyp@1794: // the initial-mark work and start a marking cycle. tonyp@1794: void decide_on_conc_mark_initiation(); ysr@777: ysr@777: // If an expansion would be appropriate, because recent GC overhead had ysr@777: // exceeded the desired limit, return an amount to expand by. tonyp@3209: size_t expansion_amount(); ysr@777: ysr@777: // Print tracing information. ysr@777: void print_tracing_info() const; ysr@777: ysr@777: // Print stats on young survival ratio ysr@777: void print_yg_surv_rate_info() const; ysr@777: apetrusenko@980: void finished_recalculating_age_indexes(bool is_survivors) { apetrusenko@980: if (is_survivors) { apetrusenko@980: _survivor_surv_rate_group->finished_recalculating_age_indexes(); apetrusenko@980: } else { apetrusenko@980: _short_lived_surv_rate_group->finished_recalculating_age_indexes(); apetrusenko@980: } ysr@777: // do that for any other surv rate groups ysr@777: } ysr@777: brutisso@6376: size_t young_list_target_length() const { return _young_list_target_length; } brutisso@6376: tonyp@2315: bool is_young_list_full() { tonyp@3713: uint young_list_length = _g1->young_list()->length(); tonyp@3713: uint young_list_target_length = _young_list_target_length; tonyp@2333: return young_list_length >= young_list_target_length; tonyp@2333: } tonyp@2333: tonyp@2333: bool can_expand_young_list() { tonyp@3713: uint young_list_length = _g1->young_list()->length(); tonyp@3713: uint young_list_max_length = _young_list_max_length; tonyp@2333: return young_list_length < young_list_max_length; tonyp@2333: } tonyp@2315: tonyp@3713: uint young_list_max_length() { tonyp@3176: return _young_list_max_length; tonyp@3176: } tonyp@3176: tonyp@3337: bool gcs_are_young() { tonyp@3337: return _gcs_are_young; ysr@777: } tonyp@3337: void set_gcs_are_young(bool gcs_are_young) { tonyp@3337: _gcs_are_young = gcs_are_young; ysr@777: } ysr@777: ysr@777: bool adaptive_young_list_length() { brutisso@3358: return _young_gen_sizer->adaptive_young_list_length(); ysr@777: } ysr@777: tonyp@3209: private: ysr@777: // ysr@777: // Survivor regions policy. ysr@777: // ysr@777: ysr@777: // Current tenuring threshold, set to 0 if the collector reaches the jwilhelm@4129: // maximum amount of survivors regions. jwilhelm@4129: uint _tenuring_threshold; ysr@777: apetrusenko@980: // The limit on the number of regions allocated for survivors. tonyp@3713: uint _max_survivor_regions; apetrusenko@980: tonyp@2961: // For reporting purposes. johnc@5123: // The value of _heap_bytes_before_gc is also used to calculate johnc@5123: // the cost of copying. johnc@5123: johnc@5123: size_t _eden_used_bytes_before_gc; // Eden occupancy before GC johnc@5123: size_t _survivor_used_bytes_before_gc; // Survivor occupancy before GC johnc@5123: size_t _heap_used_bytes_before_gc; // Heap occupancy before GC johnc@5123: size_t _metaspace_used_bytes_before_gc; // Metaspace occupancy before GC johnc@5123: johnc@5123: size_t _eden_capacity_bytes_before_gc; // Eden capacity before GC johnc@5123: size_t _heap_capacity_bytes_before_gc; // Heap capacity before GC tonyp@2961: jwilhelm@4129: // The amount of survivor regions after a collection. tonyp@3713: uint _recorded_survivor_regions; apetrusenko@980: // List of survivor regions. apetrusenko@980: HeapRegion* _recorded_survivor_head; apetrusenko@980: HeapRegion* _recorded_survivor_tail; apetrusenko@980: apetrusenko@980: ageTable _survivors_age_table; apetrusenko@980: ysr@777: public: sla@5237: uint tenuring_threshold() const { return _tenuring_threshold; } ysr@777: ysr@777: inline GCAllocPurpose jwilhelm@4129: evacuation_destination(HeapRegion* src_region, uint age, size_t word_sz) { ysr@777: if (age < _tenuring_threshold && src_region->is_young()) { ysr@777: return GCAllocForSurvived; ysr@777: } else { ysr@777: return GCAllocForTenured; ysr@777: } ysr@777: } ysr@777: ysr@777: inline bool track_object_age(GCAllocPurpose purpose) { ysr@777: return purpose == GCAllocForSurvived; ysr@777: } ysr@777: tonyp@3713: static const uint REGIONS_UNLIMITED = (uint) -1; apetrusenko@980: tonyp@3713: uint max_regions(int purpose); ysr@777: ysr@777: // The limit on regions for a particular purpose is reached. ysr@777: void note_alloc_region_limit_reached(int purpose) { ysr@777: if (purpose == GCAllocForSurvived) { ysr@777: _tenuring_threshold = 0; ysr@777: } ysr@777: } ysr@777: ysr@777: void note_start_adding_survivor_regions() { ysr@777: _survivor_surv_rate_group->start_adding_regions(); ysr@777: } ysr@777: ysr@777: void note_stop_adding_survivor_regions() { ysr@777: _survivor_surv_rate_group->stop_adding_regions(); ysr@777: } apetrusenko@980: tonyp@3713: void record_survivor_regions(uint regions, apetrusenko@980: HeapRegion* head, apetrusenko@980: HeapRegion* tail) { apetrusenko@980: _recorded_survivor_regions = regions; apetrusenko@980: _recorded_survivor_head = head; apetrusenko@980: _recorded_survivor_tail = tail; apetrusenko@980: } apetrusenko@980: tonyp@3713: uint recorded_survivor_regions() { tonyp@1273: return _recorded_survivor_regions; tonyp@1273: } tonyp@1273: tonyp@3713: void record_thread_age_table(ageTable* age_table) { apetrusenko@980: _survivors_age_table.merge_par(age_table); apetrusenko@980: } apetrusenko@980: tonyp@3119: void update_max_gc_locker_expansion(); tonyp@2333: apetrusenko@980: // Calculates survivor space parameters. tonyp@3119: void update_survivors_policy(); apetrusenko@980: jwilhelm@6085: virtual void post_heap_initialize(); ysr@777: }; ysr@777: ysr@777: // This should move to some place more general... ysr@777: ysr@777: // If we have "n" measurements, and we've kept track of their "sum" and the ysr@777: // "sum_of_squares" of the measurements, this returns the variance of the ysr@777: // sequence. ysr@777: inline double variance(int n, double sum_of_squares, double sum) { ysr@777: double n_d = (double)n; ysr@777: double avg = sum/n_d; ysr@777: return (sum_of_squares - 2.0 * avg * sum + n_d * avg * avg) / n_d; ysr@777: } ysr@777: stefank@2314: #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTORPOLICY_HPP