ysr@777: /* xdono@1014: * Copyright 2001-2009 Sun Microsystems, Inc. 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: * ysr@777: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, ysr@777: * CA 95054 USA or visit www.sun.com if you need additional information or ysr@777: * have any questions. ysr@777: * ysr@777: */ ysr@777: 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; ysr@777: ysr@777: // Yes, this is a bit unpleasant... but it saves replicating the same thing ysr@777: // over and over again and introducing subtle problems through small typos and ysr@777: // cutting and pasting mistakes. The macros below introduces a number ysr@777: // sequnce into the following two classes and the methods that access it. ysr@777: ysr@777: #define define_num_seq(name) \ ysr@777: private: \ ysr@777: NumberSeq _all_##name##_times_ms; \ ysr@777: public: \ ysr@777: void record_##name##_time_ms(double ms) { \ ysr@777: _all_##name##_times_ms.add(ms); \ ysr@777: } \ ysr@777: NumberSeq* get_##name##_seq() { \ ysr@777: return &_all_##name##_times_ms; \ ysr@777: } ysr@777: ysr@777: class MainBodySummary; ysr@777: apetrusenko@984: class PauseSummary: public CHeapObj { ysr@777: define_num_seq(total) ysr@777: define_num_seq(other) ysr@777: ysr@777: public: ysr@777: virtual MainBodySummary* main_body_summary() { return NULL; } ysr@777: }; ysr@777: apetrusenko@984: class MainBodySummary: public CHeapObj { ysr@777: define_num_seq(satb_drain) // optional ysr@777: define_num_seq(parallel) // parallel only ysr@777: define_num_seq(ext_root_scan) ysr@777: define_num_seq(mark_stack_scan) ysr@777: define_num_seq(scan_only) ysr@777: define_num_seq(update_rs) ysr@777: define_num_seq(scan_rs) ysr@777: define_num_seq(scan_new_refs) // Only for temp use; added to ysr@777: // in parallel case. ysr@777: define_num_seq(obj_copy) ysr@777: define_num_seq(termination) // parallel only ysr@777: define_num_seq(parallel_other) // parallel only ysr@777: define_num_seq(mark_closure) ysr@777: define_num_seq(clear_ct) // parallel only ysr@777: }; ysr@777: apetrusenko@1112: class Summary: public PauseSummary, apetrusenko@1112: public MainBodySummary { ysr@777: public: ysr@777: virtual MainBodySummary* main_body_summary() { return this; } ysr@777: }; ysr@777: apetrusenko@1112: class AbandonedSummary: public PauseSummary { ysr@777: }; ysr@777: ysr@777: class G1CollectorPolicy: public CollectorPolicy { ysr@777: protected: ysr@777: // The number of pauses during the execution. ysr@777: long _n_pauses; ysr@777: 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: ysr@777: enum SomePrivateConstants { ysr@777: NumPrevPausesForHeuristics = 10, ysr@777: NumPrevGCsForHeuristics = 10, ysr@777: NumAPIs = HeapRegion::MaxAge ysr@777: }; ysr@777: ysr@777: G1MMUTracker* _mmu_tracker; ysr@777: ysr@777: void initialize_flags(); ysr@777: ysr@777: void initialize_all() { ysr@777: initialize_flags(); ysr@777: initialize_size_info(); ysr@777: initialize_perm_generation(PermGen::MarkSweepCompact); ysr@777: } ysr@777: ysr@777: virtual size_t default_init_heap_size() { ysr@777: // Pick some reasonable default. ysr@777: return 8*M; ysr@777: } ysr@777: ysr@777: ysr@777: double _cur_collection_start_sec; ysr@777: size_t _cur_collection_pause_used_at_start_bytes; ysr@777: size_t _cur_collection_pause_used_regions_at_start; ysr@777: size_t _prev_collection_pause_used_at_end_bytes; ysr@777: double _cur_collection_par_time_ms; ysr@777: double _cur_satb_drain_time_ms; ysr@777: double _cur_clear_ct_time_ms; ysr@777: bool _satb_drain_time_set; ysr@777: ysr@777: double _cur_CH_strong_roots_end_sec; ysr@777: double _cur_CH_strong_roots_dur_ms; ysr@777: double _cur_G1_strong_roots_end_sec; ysr@777: double _cur_G1_strong_roots_dur_ms; ysr@777: ysr@777: // Statistics for recent GC pauses. See below for how indexed. ysr@777: TruncatedSeq* _recent_CH_strong_roots_times_ms; ysr@777: TruncatedSeq* _recent_G1_strong_roots_times_ms; ysr@777: TruncatedSeq* _recent_evac_times_ms; ysr@777: // These exclude marking times. ysr@777: TruncatedSeq* _recent_pause_times_ms; ysr@777: TruncatedSeq* _recent_gc_times_ms; ysr@777: ysr@777: TruncatedSeq* _recent_CS_bytes_used_before; ysr@777: TruncatedSeq* _recent_CS_bytes_surviving; ysr@777: ysr@777: TruncatedSeq* _recent_rs_sizes; ysr@777: ysr@777: TruncatedSeq* _concurrent_mark_init_times_ms; ysr@777: TruncatedSeq* _concurrent_mark_remark_times_ms; ysr@777: TruncatedSeq* _concurrent_mark_cleanup_times_ms; ysr@777: apetrusenko@1112: Summary* _summary; apetrusenko@1112: AbandonedSummary* _abandoned_summary; ysr@777: ysr@777: NumberSeq* _all_pause_times_ms; ysr@777: NumberSeq* _all_full_gc_times_ms; ysr@777: double _stop_world_start; ysr@777: NumberSeq* _all_stop_world_times_ms; ysr@777: NumberSeq* _all_yield_times_ms; ysr@777: ysr@777: size_t _region_num_young; ysr@777: size_t _region_num_tenured; ysr@777: size_t _prev_region_num_young; ysr@777: size_t _prev_region_num_tenured; ysr@777: ysr@777: NumberSeq* _all_mod_union_times_ms; ysr@777: ysr@777: int _aux_num; ysr@777: NumberSeq* _all_aux_times_ms; ysr@777: double* _cur_aux_start_times_ms; ysr@777: double* _cur_aux_times_ms; ysr@777: bool* _cur_aux_times_set; ysr@777: ysr@777: double* _par_last_ext_root_scan_times_ms; ysr@777: double* _par_last_mark_stack_scan_times_ms; ysr@777: double* _par_last_scan_only_times_ms; ysr@777: double* _par_last_scan_only_regions_scanned; ysr@777: double* _par_last_update_rs_start_times_ms; ysr@777: double* _par_last_update_rs_times_ms; ysr@777: double* _par_last_update_rs_processed_buffers; ysr@777: double* _par_last_scan_rs_start_times_ms; ysr@777: double* _par_last_scan_rs_times_ms; ysr@777: double* _par_last_scan_new_refs_times_ms; ysr@777: double* _par_last_obj_copy_times_ms; ysr@777: double* _par_last_termination_times_ms; ysr@777: ysr@777: // indicates that we are in young GC mode ysr@777: bool _in_young_gc_mode; ysr@777: ysr@777: // indicates whether we are in full young or partially young GC mode ysr@777: bool _full_young_gcs; ysr@777: ysr@777: // if true, then it tries to dynamically adjust the length of the ysr@777: // young list ysr@777: bool _adaptive_young_list_length; ysr@777: size_t _young_list_min_length; ysr@777: size_t _young_list_target_length; ysr@777: size_t _young_list_so_prefix_length; ysr@777: size_t _young_list_fixed_length; ysr@777: ysr@777: size_t _young_cset_length; ysr@777: bool _last_young_gc_full; ysr@777: ysr@777: double _target_pause_time_ms; ysr@777: ysr@777: unsigned _full_young_pause_num; ysr@777: unsigned _partial_young_pause_num; 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: ysr@777: bool during_marking() { ysr@777: return _during_marking; ysr@777: } ysr@777: ysr@777: // ysr@777: ysr@777: private: 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* _pending_card_diff_seq; ysr@777: TruncatedSeq* _rs_length_diff_seq; ysr@777: TruncatedSeq* _cost_per_card_ms_seq; ysr@777: TruncatedSeq* _cost_per_scan_only_region_ms_seq; ysr@777: TruncatedSeq* _fully_young_cards_per_entry_ratio_seq; ysr@777: TruncatedSeq* _partially_young_cards_per_entry_ratio_seq; ysr@777: TruncatedSeq* _cost_per_entry_ms_seq; ysr@777: TruncatedSeq* _partially_young_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* _scanned_cards_seq; ysr@777: TruncatedSeq* _rs_lengths_seq; ysr@777: ysr@777: TruncatedSeq* _cost_per_byte_ms_during_cm_seq; ysr@777: TruncatedSeq* _cost_per_scan_only_region_ms_during_cm_seq; ysr@777: ysr@777: TruncatedSeq* _young_gc_eff_seq; ysr@777: ysr@777: TruncatedSeq* _max_conc_overhead_seq; ysr@777: ysr@777: size_t _recorded_young_regions; ysr@777: size_t _recorded_scan_only_regions; ysr@777: size_t _recorded_non_young_regions; ysr@777: size_t _recorded_region_num; ysr@777: ysr@777: size_t _free_regions_at_end_of_collection; ysr@777: size_t _scan_only_regions_at_end_of_collection; ysr@777: ysr@777: size_t _recorded_rs_lengths; ysr@777: size_t _max_rs_lengths; ysr@777: ysr@777: size_t _recorded_marked_bytes; ysr@777: size_t _recorded_young_bytes; ysr@777: ysr@777: size_t _predicted_pending_cards; ysr@777: size_t _predicted_cards_scanned; ysr@777: size_t _predicted_rs_lengths; ysr@777: size_t _predicted_bytes_to_copy; ysr@777: ysr@777: double _predicted_survival_ratio; ysr@777: double _predicted_rs_update_time_ms; ysr@777: double _predicted_rs_scan_time_ms; ysr@777: double _predicted_scan_only_scan_time_ms; ysr@777: double _predicted_object_copy_time_ms; ysr@777: double _predicted_constant_other_time_ms; ysr@777: double _predicted_young_other_time_ms; ysr@777: double _predicted_non_young_other_time_ms; ysr@777: double _predicted_pause_time_ms; ysr@777: ysr@777: double _vtime_diff_ms; ysr@777: ysr@777: double _recorded_young_free_cset_time_ms; ysr@777: double _recorded_non_young_free_cset_time_ms; ysr@777: ysr@777: double _sigma; ysr@777: double _expensive_region_limit_ms; ysr@777: ysr@777: size_t _rs_lengths_prediction; ysr@777: ysr@777: size_t _known_garbage_bytes; ysr@777: double _known_garbage_ratio; ysr@777: ysr@777: double sigma() { ysr@777: return _sigma; ysr@777: } 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: ysr@777: protected: ysr@777: double _pause_time_target_ms; ysr@777: double _recorded_young_cset_choice_time_ms; ysr@777: double _recorded_non_young_cset_choice_time_ms; ysr@777: bool _within_target; ysr@777: size_t _pending_cards; ysr@777: size_t _max_pending_cards; ysr@777: ysr@777: public: ysr@777: ysr@777: void set_region_short_lived(HeapRegion* hr) { ysr@777: hr->install_surv_rate_group(_short_lived_surv_rate_group); ysr@777: } ysr@777: ysr@777: void set_region_survivors(HeapRegion* hr) { ysr@777: hr->install_surv_rate_group(_survivor_surv_rate_group); ysr@777: } ysr@777: ysr@777: #ifndef PRODUCT ysr@777: bool verify_young_ages(); ysr@777: #endif // PRODUCT ysr@777: ysr@777: void tag_scan_only(size_t short_lived_scan_only_length); 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: size_t young_cset_length() { ysr@777: return _young_cset_length; 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_pending_card_diff() { ysr@777: double prediction = get_new_neg_prediction(_pending_card_diff_seq); ysr@777: if (prediction < 0.00001) ysr@777: return 0; ysr@777: else ysr@777: return (size_t) prediction; ysr@777: } ysr@777: ysr@777: size_t predict_pending_cards() { ysr@777: size_t max_pending_card_num = _g1->max_pending_card_num(); ysr@777: size_t diff = predict_pending_card_diff(); ysr@777: size_t prediction; ysr@777: if (diff > max_pending_card_num) ysr@777: prediction = max_pending_card_num; ysr@777: else ysr@777: prediction = max_pending_card_num - diff; ysr@777: ysr@777: return prediction; 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: ysr@777: double predict_fully_young_cards_per_entry_ratio() { ysr@777: return get_new_prediction(_fully_young_cards_per_entry_ratio_seq); ysr@777: } ysr@777: ysr@777: double predict_partially_young_cards_per_entry_ratio() { ysr@777: if (_partially_young_cards_per_entry_ratio_seq->num() < 2) ysr@777: return predict_fully_young_cards_per_entry_ratio(); ysr@777: else ysr@777: return get_new_prediction(_partially_young_cards_per_entry_ratio_seq); ysr@777: } ysr@777: ysr@777: size_t predict_young_card_num(size_t rs_length) { ysr@777: return (size_t) ((double) rs_length * ysr@777: predict_fully_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 * ysr@777: predict_partially_young_cards_per_entry_ratio()); ysr@777: } ysr@777: ysr@777: double predict_rs_scan_time_ms(size_t card_num) { ysr@777: if (full_young_gcs()) ysr@777: return (double) card_num * get_new_prediction(_cost_per_entry_ms_seq); ysr@777: else ysr@777: return predict_partially_young_rs_scan_time_ms(card_num); ysr@777: } ysr@777: ysr@777: double predict_partially_young_rs_scan_time_ms(size_t card_num) { ysr@777: if (_partially_young_cost_per_entry_ms_seq->num() < 3) ysr@777: return (double) card_num * get_new_prediction(_cost_per_entry_ms_seq); ysr@777: else ysr@777: return (double) card_num * ysr@777: get_new_prediction(_partially_young_cost_per_entry_ms_seq); ysr@777: } ysr@777: ysr@777: double predict_scan_only_time_ms_during_cm(size_t scan_only_region_num) { ysr@777: if (_cost_per_scan_only_region_ms_during_cm_seq->num() < 3) ysr@777: return 1.5 * (double) scan_only_region_num * ysr@777: get_new_prediction(_cost_per_scan_only_region_ms_seq); ysr@777: else ysr@777: return (double) scan_only_region_num * ysr@777: get_new_prediction(_cost_per_scan_only_region_ms_during_cm_seq); ysr@777: } ysr@777: ysr@777: double predict_scan_only_time_ms(size_t scan_only_region_num) { ysr@777: if (_in_marking_window_im) ysr@777: return predict_scan_only_time_ms_during_cm(scan_only_region_num); ysr@777: else ysr@777: return (double) scan_only_region_num * ysr@777: get_new_prediction(_cost_per_scan_only_region_ms_seq); ysr@777: } ysr@777: ysr@777: double predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) { ysr@777: if (_cost_per_byte_ms_during_cm_seq->num() < 3) ysr@777: return 1.1 * (double) bytes_to_copy * ysr@777: get_new_prediction(_cost_per_byte_ms_seq); ysr@777: else ysr@777: return (double) bytes_to_copy * ysr@777: get_new_prediction(_cost_per_byte_ms_during_cm_seq); ysr@777: } ysr@777: ysr@777: double predict_object_copy_time_ms(size_t bytes_to_copy) { ysr@777: if (_in_marking_window && !_in_marking_window_im) ysr@777: return predict_object_copy_time_ms_during_cm(bytes_to_copy); ysr@777: else ysr@777: return (double) bytes_to_copy * ysr@777: get_new_prediction(_cost_per_byte_ms_seq); 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) { ysr@777: return ysr@777: (double) young_num * ysr@777: 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) { ysr@777: return ysr@777: (double) non_young_num * ysr@777: get_new_prediction(_non_young_other_cost_per_region_ms_seq); ysr@777: } ysr@777: ysr@777: void check_if_region_is_too_expensive(double predicted_time_ms); ysr@777: ysr@777: double predict_young_collection_elapsed_time_ms(size_t adjustment); 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); ysr@777: double predict_region_elapsed_time_ms(HeapRegion* hr, bool young); ysr@777: ysr@777: // for use by: calculate_optimal_so_length(length) ysr@777: void predict_gc_eff(size_t young_region_num, ysr@777: size_t so_length, ysr@777: double base_time_ms, ysr@777: double *gc_eff, ysr@777: double *pause_time_ms); ysr@777: ysr@777: // for use by: calculate_young_list_target_config(rs_length) ysr@777: bool predict_gc_eff(size_t young_region_num, ysr@777: size_t so_length, ysr@777: double base_time_with_so_ms, ysr@777: size_t init_free_regions, ysr@777: double target_pause_time_ms, ysr@777: double* gc_eff); ysr@777: ysr@777: void start_recording_regions(); ysr@777: void record_cset_region(HeapRegion* hr, bool young); ysr@777: void record_scan_only_regions(size_t scan_only_length); ysr@777: void end_recording_regions(); ysr@777: ysr@777: void record_vtime_diff_ms(double vtime_diff_ms) { ysr@777: _vtime_diff_ms = vtime_diff_ms; ysr@777: } ysr@777: ysr@777: void record_young_free_cset_time_ms(double time_ms) { ysr@777: _recorded_young_free_cset_time_ms = time_ms; ysr@777: } ysr@777: ysr@777: void record_non_young_free_cset_time_ms(double time_ms) { ysr@777: _recorded_non_young_free_cset_time_ms = time_ms; ysr@777: } ysr@777: ysr@777: double predict_young_gc_eff() { ysr@777: return get_new_neg_prediction(_young_gc_eff_seq); ysr@777: } ysr@777: apetrusenko@980: double predict_survivor_regions_evac_time(); apetrusenko@980: ysr@777: // ysr@777: ysr@777: public: ysr@777: void cset_regions_freed() { ysr@777: bool propagate = _last_young_gc_full && !_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: void set_known_garbage_bytes(size_t known_garbage_bytes) { ysr@777: _known_garbage_bytes = known_garbage_bytes; ysr@777: size_t heap_bytes = _g1->capacity(); ysr@777: _known_garbage_ratio = (double) _known_garbage_bytes / (double) heap_bytes; ysr@777: } ysr@777: ysr@777: void decrease_known_garbage_bytes(size_t known_garbage_bytes) { ysr@777: guarantee( _known_garbage_bytes >= known_garbage_bytes, "invariant" ); ysr@777: ysr@777: _known_garbage_bytes -= known_garbage_bytes; ysr@777: size_t heap_bytes = _g1->capacity(); ysr@777: _known_garbage_ratio = (double) _known_garbage_bytes / (double) heap_bytes; ysr@777: } ysr@777: ysr@777: G1MMUTracker* mmu_tracker() { ysr@777: return _mmu_tracker; ysr@777: } ysr@777: ysr@777: double predict_init_time_ms() { ysr@777: return get_new_prediction(_concurrent_mark_init_times_ms); ysr@777: } ysr@777: 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: ysr@777: protected: ysr@777: void print_stats (int level, const char* str, double value); ysr@777: void print_stats (int level, const char* str, int value); ysr@777: void print_par_stats (int level, const char* str, double* data) { ysr@777: print_par_stats(level, str, data, true); ysr@777: } ysr@777: void print_par_stats (int level, const char* str, double* data, bool summary); ysr@777: void print_par_buffers (int level, const char* str, double* data, bool summary); ysr@777: ysr@777: void check_other_times(int level, ysr@777: NumberSeq* other_times_ms, ysr@777: NumberSeq* calc_other_times_ms) const; ysr@777: ysr@777: void print_summary (PauseSummary* stats) const; apetrusenko@1112: void print_abandoned_summary(PauseSummary* summary) const; ysr@777: ysr@777: void print_summary (int level, const char* str, NumberSeq* seq) const; ysr@777: void print_summary_sd (int level, const char* str, NumberSeq* seq) const; ysr@777: ysr@777: double avg_value (double* data); ysr@777: double max_value (double* data); ysr@777: double sum_of_values (double* data); ysr@777: double max_sum (double* data1, double* data2); ysr@777: ysr@777: int _last_satb_drain_processed_buffers; ysr@777: int _last_update_rs_processed_buffers; ysr@777: double _last_pause_time_ms; ysr@777: ysr@777: size_t _bytes_in_to_space_before_gc; ysr@777: size_t _bytes_in_to_space_after_gc; ysr@777: size_t bytes_in_to_space_during_gc() { ysr@777: return ysr@777: _bytes_in_to_space_after_gc - _bytes_in_to_space_before_gc; ysr@777: } ysr@777: size_t _bytes_in_collection_set_before_gc; ysr@777: // Used to count used bytes in CS. ysr@777: friend class CountCSClosure; ysr@777: 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: // We track markings. ysr@777: int _num_markings; ysr@777: double _mark_thread_startup_sec; // Time at startup of marking thread 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 ysr@777: // current collection set. ysr@777: HeapRegion* _collection_set; ysr@777: size_t _collection_set_size; ysr@777: size_t _collection_set_bytes_used_before; ysr@777: ysr@777: // Info about marking. ysr@777: int _n_marks; // Sticky at 2, so we know when we've done at least 2. ysr@777: ysr@777: // The number of collection pauses at the end of the last mark. ysr@777: size_t _n_pauses_at_mark_end; ysr@777: ysr@777: // Stash a pointer to the g1 heap. ysr@777: G1CollectedHeap* _g1; ysr@777: ysr@777: // The average time in ms per collection pause, averaged over recent pauses. ysr@777: double recent_avg_time_for_pauses_ms(); ysr@777: ysr@777: // The average time in ms for processing CollectedHeap strong roots, per ysr@777: // collection pause, averaged over recent pauses. ysr@777: double recent_avg_time_for_CH_strong_ms(); ysr@777: ysr@777: // The average time in ms for processing the G1 remembered set, per ysr@777: // pause, averaged over recent pauses. ysr@777: double recent_avg_time_for_G1_strong_ms(); ysr@777: ysr@777: // The average time in ms for "evacuating followers", per pause, averaged ysr@777: // over recent pauses. ysr@777: double recent_avg_time_for_evac_ms(); ysr@777: ysr@777: // The number of "recent" GCs recorded in the number sequences ysr@777: int number_of_recent_gcs(); ysr@777: ysr@777: // The average survival ratio, computed by the total number of bytes ysr@777: // suriviving / total number of bytes before collection over the last ysr@777: // several recent pauses. ysr@777: double recent_avg_survival_fraction(); ysr@777: // The survival fraction of the most recent pause; if there have been no ysr@777: // pauses, returns 1.0. ysr@777: double last_survival_fraction(); ysr@777: ysr@777: // Returns a "conservative" estimate of the recent survival rate, i.e., ysr@777: // one that may be higher than "recent_avg_survival_fraction". ysr@777: // This is conservative in several ways: ysr@777: // If there have been few pauses, it will assume a potential high ysr@777: // variance, and err on the side of caution. ysr@777: // It puts a lower bound (currently 0.1) on the value it will return. ysr@777: // To try to detect phase changes, if the most recent pause ("latest") has a ysr@777: // higher-than average ("avg") survival rate, it returns that rate. ysr@777: // "work" version is a utility function; young is restricted to young regions. ysr@777: double conservative_avg_survival_fraction_work(double avg, ysr@777: double latest); ysr@777: ysr@777: // The arguments are the two sequences that keep track of the number of bytes ysr@777: // surviving and the total number of bytes before collection, resp., ysr@777: // over the last evereal recent pauses ysr@777: // Returns the survival rate for the category in the most recent pause. ysr@777: // If there have been no pauses, returns 1.0. ysr@777: double last_survival_fraction_work(TruncatedSeq* surviving, ysr@777: TruncatedSeq* before); ysr@777: ysr@777: // The arguments are the two sequences that keep track of the number of bytes ysr@777: // surviving and the total number of bytes before collection, resp., ysr@777: // over the last several recent pauses ysr@777: // Returns the average survival ration over the last several recent pauses ysr@777: // If there have been no pauses, return 1.0 ysr@777: double recent_avg_survival_fraction_work(TruncatedSeq* surviving, ysr@777: TruncatedSeq* before); ysr@777: ysr@777: double conservative_avg_survival_fraction() { ysr@777: double avg = recent_avg_survival_fraction(); ysr@777: double latest = last_survival_fraction(); ysr@777: return conservative_avg_survival_fraction_work(avg, latest); ysr@777: } ysr@777: 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: ysr@777: // Number of pauses between concurrent marking. ysr@777: size_t _pauses_btwn_concurrent_mark; ysr@777: ysr@777: size_t _n_marks_since_last_pause; ysr@777: ysr@777: // True iff CM has been initiated. ysr@777: bool _conc_mark_initiated; ysr@777: ysr@777: // True iff CM should be initiated ysr@777: bool _should_initiate_conc_mark; ysr@777: bool _should_revert_to_full_young_gcs; ysr@777: bool _last_full_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_init_start_sec; ysr@777: double _mark_remark_start_sec; ysr@777: double _mark_cleanup_start_sec; ysr@777: double _mark_closure_time_ms; ysr@777: ysr@777: void calculate_young_list_min_length(); ysr@777: void calculate_young_list_target_config(); ysr@777: void calculate_young_list_target_config(size_t rs_lengths); ysr@777: size_t calculate_optimal_so_length(size_t young_list_length); ysr@777: 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: ysr@777: void check_prediction_validity(); ysr@777: ysr@777: size_t bytes_in_collection_set() { ysr@777: return _bytes_in_collection_set_before_gc; ysr@777: } ysr@777: ysr@777: size_t bytes_in_to_space() { ysr@777: return bytes_in_to_space_during_gc(); ysr@777: } ysr@777: ysr@777: unsigned calc_gc_alloc_time_stamp() { ysr@777: return _all_pause_times_ms->num() + 1; ysr@777: } ysr@777: ysr@777: protected: ysr@777: ysr@777: // Count the number of bytes used in the CS. ysr@777: void count_CS_bytes_used(); ysr@777: ysr@777: // Together these do the base cleanup-recording work. Subclasses might ysr@777: // want to put something between them. ysr@777: void record_concurrent_mark_cleanup_end_work1(size_t freed_bytes, ysr@777: size_t max_live_bytes); ysr@777: void record_concurrent_mark_cleanup_end_work2(); ysr@777: ysr@777: public: ysr@777: ysr@777: virtual 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: ysr@777: GenRemSet::Name rem_set_name() { return GenRemSet::CardTable; } ysr@777: ysr@777: // The number of collection pauses so far. ysr@777: long n_pauses() const { return _n_pauses; } ysr@777: ysr@777: // Update the heuristic info to record a collection pause of the given ysr@777: // start time, where the given number of bytes were used at the start. ysr@777: // This may involve changing the desired size of a collection set. ysr@777: ysr@777: virtual void record_stop_world_start(); ysr@777: ysr@777: virtual void record_collection_pause_start(double start_time_sec, ysr@777: size_t start_used); ysr@777: ysr@777: // Must currently be called while the world is stopped. ysr@777: virtual void record_concurrent_mark_init_start(); ysr@777: virtual void record_concurrent_mark_init_end(); ysr@777: void record_concurrent_mark_init_end_pre(double ysr@777: mark_init_elapsed_time_ms); ysr@777: ysr@777: void record_mark_closure_time(double mark_closure_time_ms); ysr@777: ysr@777: virtual void record_concurrent_mark_remark_start(); ysr@777: virtual void record_concurrent_mark_remark_end(); ysr@777: ysr@777: virtual void record_concurrent_mark_cleanup_start(); ysr@777: virtual void record_concurrent_mark_cleanup_end(size_t freed_bytes, ysr@777: size_t max_live_bytes); ysr@777: virtual void record_concurrent_mark_cleanup_completed(); ysr@777: ysr@777: virtual void record_concurrent_pause(); ysr@777: virtual void record_concurrent_pause_end(); ysr@777: ysr@777: virtual void record_collection_pause_end_CH_strong_roots(); ysr@777: virtual void record_collection_pause_end_G1_strong_roots(); ysr@777: apetrusenko@1112: virtual void record_collection_pause_end(bool abandoned); ysr@777: ysr@777: // Record the fact that a full collection occurred. ysr@777: virtual void record_full_collection_start(); ysr@777: virtual void record_full_collection_end(); ysr@777: ysr@777: void record_ext_root_scan_time(int worker_i, double ms) { ysr@777: _par_last_ext_root_scan_times_ms[worker_i] = ms; ysr@777: } ysr@777: ysr@777: void record_mark_stack_scan_time(int worker_i, double ms) { ysr@777: _par_last_mark_stack_scan_times_ms[worker_i] = ms; ysr@777: } ysr@777: ysr@777: void record_scan_only_time(int worker_i, double ms, int n) { ysr@777: _par_last_scan_only_times_ms[worker_i] = ms; ysr@777: _par_last_scan_only_regions_scanned[worker_i] = (double) n; ysr@777: } ysr@777: ysr@777: void record_satb_drain_time(double ms) { ysr@777: _cur_satb_drain_time_ms = ms; ysr@777: _satb_drain_time_set = true; ysr@777: } ysr@777: ysr@777: void record_satb_drain_processed_buffers (int processed_buffers) { ysr@777: _last_satb_drain_processed_buffers = processed_buffers; ysr@777: } ysr@777: ysr@777: void record_mod_union_time(double ms) { ysr@777: _all_mod_union_times_ms->add(ms); ysr@777: } ysr@777: ysr@777: void record_update_rs_start_time(int thread, double ms) { ysr@777: _par_last_update_rs_start_times_ms[thread] = ms; ysr@777: } ysr@777: ysr@777: void record_update_rs_time(int thread, double ms) { ysr@777: _par_last_update_rs_times_ms[thread] = ms; ysr@777: } ysr@777: ysr@777: void record_update_rs_processed_buffers (int thread, ysr@777: double processed_buffers) { ysr@777: _par_last_update_rs_processed_buffers[thread] = processed_buffers; ysr@777: } ysr@777: ysr@777: void record_scan_rs_start_time(int thread, double ms) { ysr@777: _par_last_scan_rs_start_times_ms[thread] = ms; ysr@777: } ysr@777: ysr@777: void record_scan_rs_time(int thread, double ms) { ysr@777: _par_last_scan_rs_times_ms[thread] = ms; ysr@777: } ysr@777: ysr@777: void record_scan_new_refs_time(int thread, double ms) { ysr@777: _par_last_scan_new_refs_times_ms[thread] = ms; ysr@777: } ysr@777: ysr@777: double get_scan_new_refs_time(int thread) { ysr@777: return _par_last_scan_new_refs_times_ms[thread]; ysr@777: } ysr@777: ysr@777: void reset_obj_copy_time(int thread) { ysr@777: _par_last_obj_copy_times_ms[thread] = 0.0; ysr@777: } ysr@777: ysr@777: void reset_obj_copy_time() { ysr@777: reset_obj_copy_time(0); ysr@777: } ysr@777: ysr@777: void record_obj_copy_time(int thread, double ms) { ysr@777: _par_last_obj_copy_times_ms[thread] += ms; ysr@777: } ysr@777: ysr@777: void record_obj_copy_time(double ms) { ysr@777: record_obj_copy_time(0, ms); ysr@777: } ysr@777: ysr@777: void record_termination_time(int thread, double ms) { ysr@777: _par_last_termination_times_ms[thread] = ms; ysr@777: } ysr@777: ysr@777: void record_termination_time(double ms) { ysr@777: record_termination_time(0, ms); ysr@777: } ysr@777: tonyp@1030: void record_pause_time_ms(double ms) { ysr@777: _last_pause_time_ms = ms; ysr@777: } ysr@777: ysr@777: void record_clear_ct_time(double ms) { ysr@777: _cur_clear_ct_time_ms = ms; ysr@777: } ysr@777: ysr@777: void record_par_time(double ms) { ysr@777: _cur_collection_par_time_ms = ms; ysr@777: } ysr@777: ysr@777: void record_aux_start_time(int i) { ysr@777: guarantee(i < _aux_num, "should be within range"); ysr@777: _cur_aux_start_times_ms[i] = os::elapsedTime() * 1000.0; ysr@777: } ysr@777: ysr@777: void record_aux_end_time(int i) { ysr@777: guarantee(i < _aux_num, "should be within range"); ysr@777: double ms = os::elapsedTime() * 1000.0 - _cur_aux_start_times_ms[i]; ysr@777: _cur_aux_times_set[i] = true; ysr@777: _cur_aux_times_ms[i] += ms; ysr@777: } ysr@777: ysr@777: // Record the fact that "bytes" bytes allocated in a region. ysr@777: void record_before_bytes(size_t bytes); ysr@777: void record_after_bytes(size_t bytes); ysr@777: ysr@777: // Returns "true" if this is a good time to do a collection pause. ysr@777: // The "word_size" argument, if non-zero, indicates the size of an ysr@777: // allocation request that is prompting this query. ysr@777: virtual bool should_do_collection_pause(size_t word_size) = 0; ysr@777: 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. apetrusenko@1112: virtual void choose_collection_set() = 0; ysr@777: ysr@777: void clear_collection_set() { _collection_set = NULL; } 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: ysr@777: // The number of elements in the current collection set. ysr@777: size_t collection_set_size() { return _collection_set_size; } ysr@777: ysr@777: // Add "hr" to the CS. ysr@777: void add_to_collection_set(HeapRegion* hr); ysr@777: ysr@777: bool should_initiate_conc_mark() { return _should_initiate_conc_mark; } ysr@777: void set_should_initiate_conc_mark() { _should_initiate_conc_mark = true; } ysr@777: void unset_should_initiate_conc_mark(){ _should_initiate_conc_mark = false; } ysr@777: ysr@777: void checkpoint_conc_overhead(); 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. ysr@777: virtual size_t expansion_amount(); ysr@777: ysr@777: // note start of mark thread ysr@777: void note_start_of_mark_thread(); ysr@777: ysr@777: // The marked bytes of the "r" has changed; reclassify it's desirability ysr@777: // for marking. Also asserts that "r" is eligible for a CS. ysr@777: virtual void note_change_in_marked_bytes(HeapRegion* r) = 0; ysr@777: ysr@777: #ifndef PRODUCT ysr@777: // Check any appropriate marked bytes info, asserting false if ysr@777: // something's wrong, else returning "true". ysr@777: virtual bool assertMarkedBytesDataOK() = 0; ysr@777: #endif 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: ysr@777: bool should_add_next_region_to_young_list(); ysr@777: ysr@777: bool in_young_gc_mode() { ysr@777: return _in_young_gc_mode; ysr@777: } ysr@777: void set_in_young_gc_mode(bool in_young_gc_mode) { ysr@777: _in_young_gc_mode = in_young_gc_mode; ysr@777: } ysr@777: ysr@777: bool full_young_gcs() { ysr@777: return _full_young_gcs; ysr@777: } ysr@777: void set_full_young_gcs(bool full_young_gcs) { ysr@777: _full_young_gcs = full_young_gcs; ysr@777: } ysr@777: ysr@777: bool adaptive_young_list_length() { ysr@777: return _adaptive_young_list_length; ysr@777: } ysr@777: void set_adaptive_young_list_length(bool adaptive_young_list_length) { ysr@777: _adaptive_young_list_length = adaptive_young_list_length; ysr@777: } ysr@777: ysr@777: inline double get_gc_eff_factor() { ysr@777: double ratio = _known_garbage_ratio; ysr@777: ysr@777: double square = ratio * ratio; ysr@777: // square = square * square; ysr@777: double ret = square * 9.0 + 1.0; ysr@777: #if 0 ysr@777: gclog_or_tty->print_cr("ratio = %1.2lf, ret = %1.2lf", ratio, ret); ysr@777: #endif // 0 ysr@777: guarantee(0.0 <= ret && ret < 10.0, "invariant!"); ysr@777: return ret; ysr@777: } ysr@777: ysr@777: // ysr@777: // Survivor regions policy. ysr@777: // ysr@777: protected: ysr@777: ysr@777: // Current tenuring threshold, set to 0 if the collector reaches the ysr@777: // maximum amount of suvivors regions. ysr@777: int _tenuring_threshold; ysr@777: apetrusenko@980: // The limit on the number of regions allocated for survivors. apetrusenko@980: size_t _max_survivor_regions; apetrusenko@980: apetrusenko@980: // The amount of survor regions after a collection. apetrusenko@980: size_t _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: ysr@777: ysr@777: inline GCAllocPurpose ysr@777: evacuation_destination(HeapRegion* src_region, int 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: ysr@777: inline GCAllocPurpose alternative_purpose(int purpose) { ysr@777: return GCAllocForTenured; ysr@777: } ysr@777: apetrusenko@980: static const size_t REGIONS_UNLIMITED = ~(size_t)0; apetrusenko@980: apetrusenko@980: size_t 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: apetrusenko@980: void record_survivor_regions(size_t 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@1273: size_t recorded_survivor_regions() { tonyp@1273: return _recorded_survivor_regions; tonyp@1273: } tonyp@1273: apetrusenko@980: void record_thread_age_table(ageTable* age_table) apetrusenko@980: { apetrusenko@980: _survivors_age_table.merge_par(age_table); apetrusenko@980: } apetrusenko@980: apetrusenko@980: // Calculates survivor space parameters. apetrusenko@980: void calculate_survivors_policy(); apetrusenko@980: ysr@777: }; ysr@777: ysr@777: // This encapsulates a particular strategy for a g1 Collector. ysr@777: // ysr@777: // Start a concurrent mark when our heap size is n bytes ysr@777: // greater then our heap size was at the last concurrent ysr@777: // mark. Where n is a function of the CMSTriggerRatio ysr@777: // and the MinHeapFreeRatio. ysr@777: // ysr@777: // Start a g1 collection pause when we have allocated the ysr@777: // average number of bytes currently being freed in ysr@777: // a collection, but only if it is at least one region ysr@777: // full ysr@777: // ysr@777: // Resize Heap based on desired ysr@777: // allocation space, where desired allocation space is ysr@777: // a function of survival rate and desired future to size. ysr@777: // ysr@777: // Choose collection set by first picking all older regions ysr@777: // which have a survival rate which beats our projected young ysr@777: // survival rate. Then fill out the number of needed regions ysr@777: // with young regions. ysr@777: ysr@777: class G1CollectorPolicy_BestRegionsFirst: public G1CollectorPolicy { ysr@777: CollectionSetChooser* _collectionSetChooser; ysr@777: // If the estimated is less then desirable, resize if possible. ysr@777: void expand_if_possible(size_t numRegions); ysr@777: apetrusenko@1112: virtual void choose_collection_set(); ysr@777: virtual void record_collection_pause_start(double start_time_sec, ysr@777: size_t start_used); ysr@777: virtual void record_concurrent_mark_cleanup_end(size_t freed_bytes, ysr@777: size_t max_live_bytes); ysr@777: virtual void record_full_collection_end(); ysr@777: ysr@777: public: ysr@777: G1CollectorPolicy_BestRegionsFirst() { ysr@777: _collectionSetChooser = new CollectionSetChooser(); ysr@777: } apetrusenko@1112: void record_collection_pause_end(bool abandoned); ysr@777: bool should_do_collection_pause(size_t word_size); ysr@777: // This is not needed any more, after the CSet choosing code was ysr@777: // changed to use the pause prediction work. But let's leave the ysr@777: // hook in just in case. ysr@777: void note_change_in_marked_bytes(HeapRegion* r) { } ysr@777: #ifndef PRODUCT ysr@777: bool assertMarkedBytesDataOK(); ysr@777: #endif 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: ysr@777: // Local Variables: *** ysr@777: // c-indentation-style: gnu *** ysr@777: // End: ***