diff -r 0b27f3512f9e -r 37f87013dfd8 src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp Thu Jun 05 15:57:56 2008 -0700 @@ -0,0 +1,3159 @@ +/* + * Copyright 2001-2007 Sun Microsystems, Inc. All Rights Reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +#include "incls/_precompiled.incl" +#include "incls/_g1CollectorPolicy.cpp.incl" + +#define PREDICTIONS_VERBOSE 0 + +// + +// Different defaults for different number of GC threads +// They were chosen by running GCOld and SPECjbb on debris with different +// numbers of GC threads and choosing them based on the results + +// all the same +static double rs_length_diff_defaults[] = { + 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 +}; + +static double cost_per_card_ms_defaults[] = { + 0.01, 0.005, 0.005, 0.003, 0.003, 0.002, 0.002, 0.0015 +}; + +static double cost_per_scan_only_region_ms_defaults[] = { + 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0 +}; + +// all the same +static double fully_young_cards_per_entry_ratio_defaults[] = { + 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0 +}; + +static double cost_per_entry_ms_defaults[] = { + 0.015, 0.01, 0.01, 0.008, 0.008, 0.0055, 0.0055, 0.005 +}; + +static double cost_per_byte_ms_defaults[] = { + 0.00006, 0.00003, 0.00003, 0.000015, 0.000015, 0.00001, 0.00001, 0.000009 +}; + +// these should be pretty consistent +static double constant_other_time_ms_defaults[] = { + 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0 +}; + + +static double young_other_cost_per_region_ms_defaults[] = { + 0.3, 0.2, 0.2, 0.15, 0.15, 0.12, 0.12, 0.1 +}; + +static double non_young_other_cost_per_region_ms_defaults[] = { + 1.0, 0.7, 0.7, 0.5, 0.5, 0.42, 0.42, 0.30 +}; + +// + +G1CollectorPolicy::G1CollectorPolicy() : + _parallel_gc_threads((ParallelGCThreads > 0) ? ParallelGCThreads : 1), + _n_pauses(0), + _recent_CH_strong_roots_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)), + _recent_G1_strong_roots_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)), + _recent_evac_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)), + _recent_pause_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)), + _recent_rs_sizes(new TruncatedSeq(NumPrevPausesForHeuristics)), + _recent_gc_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)), + _all_pause_times_ms(new NumberSeq()), + _stop_world_start(0.0), + _all_stop_world_times_ms(new NumberSeq()), + _all_yield_times_ms(new NumberSeq()), + + _all_mod_union_times_ms(new NumberSeq()), + + _non_pop_summary(new NonPopSummary()), + _pop_summary(new PopSummary()), + _non_pop_abandoned_summary(new NonPopAbandonedSummary()), + _pop_abandoned_summary(new PopAbandonedSummary()), + + _cur_clear_ct_time_ms(0.0), + + _region_num_young(0), + _region_num_tenured(0), + _prev_region_num_young(0), + _prev_region_num_tenured(0), + + _aux_num(10), + _all_aux_times_ms(new NumberSeq[_aux_num]), + _cur_aux_start_times_ms(new double[_aux_num]), + _cur_aux_times_ms(new double[_aux_num]), + _cur_aux_times_set(new bool[_aux_num]), + + _pop_compute_rc_start(0.0), + _pop_evac_start(0.0), + + _concurrent_mark_init_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)), + _concurrent_mark_remark_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)), + _concurrent_mark_cleanup_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)), + + // + + _alloc_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)), + _prev_collection_pause_end_ms(0.0), + _pending_card_diff_seq(new TruncatedSeq(TruncatedSeqLength)), + _rs_length_diff_seq(new TruncatedSeq(TruncatedSeqLength)), + _cost_per_card_ms_seq(new TruncatedSeq(TruncatedSeqLength)), + _cost_per_scan_only_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)), + _fully_young_cards_per_entry_ratio_seq(new TruncatedSeq(TruncatedSeqLength)), + _partially_young_cards_per_entry_ratio_seq( + new TruncatedSeq(TruncatedSeqLength)), + _cost_per_entry_ms_seq(new TruncatedSeq(TruncatedSeqLength)), + _partially_young_cost_per_entry_ms_seq(new TruncatedSeq(TruncatedSeqLength)), + _cost_per_byte_ms_seq(new TruncatedSeq(TruncatedSeqLength)), + _cost_per_byte_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)), + _cost_per_scan_only_region_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)), + _constant_other_time_ms_seq(new TruncatedSeq(TruncatedSeqLength)), + _young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)), + _non_young_other_cost_per_region_ms_seq( + new TruncatedSeq(TruncatedSeqLength)), + + _pending_cards_seq(new TruncatedSeq(TruncatedSeqLength)), + _scanned_cards_seq(new TruncatedSeq(TruncatedSeqLength)), + _rs_lengths_seq(new TruncatedSeq(TruncatedSeqLength)), + + _pause_time_target_ms((double) G1MaxPauseTimeMS), + + // + + _in_young_gc_mode(false), + _full_young_gcs(true), + _full_young_pause_num(0), + _partial_young_pause_num(0), + + _during_marking(false), + _in_marking_window(false), + _in_marking_window_im(false), + + _known_garbage_ratio(0.0), + _known_garbage_bytes(0), + + _young_gc_eff_seq(new TruncatedSeq(TruncatedSeqLength)), + _target_pause_time_ms(-1.0), + + _recent_prev_end_times_for_all_gcs_sec(new TruncatedSeq(NumPrevPausesForHeuristics)), + + _recent_CS_bytes_used_before(new TruncatedSeq(NumPrevPausesForHeuristics)), + _recent_CS_bytes_surviving(new TruncatedSeq(NumPrevPausesForHeuristics)), + + _recent_avg_pause_time_ratio(0.0), + _num_markings(0), + _n_marks(0), + _n_pauses_at_mark_end(0), + + _all_full_gc_times_ms(new NumberSeq()), + + _conc_refine_enabled(0), + _conc_refine_zero_traversals(0), + _conc_refine_max_traversals(0), + _conc_refine_current_delta(G1ConcRefineInitialDelta), + + // G1PausesBtwnConcMark defaults to -1 + // so the hack is to do the cast QQQ FIXME + _pauses_btwn_concurrent_mark((size_t)G1PausesBtwnConcMark), + _n_marks_since_last_pause(0), + _conc_mark_initiated(false), + _should_initiate_conc_mark(false), + _should_revert_to_full_young_gcs(false), + _last_full_young_gc(false), + + _prev_collection_pause_used_at_end_bytes(0), + + _collection_set(NULL), +#ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away +#pragma warning( disable:4355 ) // 'this' : used in base member initializer list +#endif // _MSC_VER + + _short_lived_surv_rate_group(new SurvRateGroup(this, "Short Lived", + G1YoungSurvRateNumRegionsSummary)), + _survivor_surv_rate_group(new SurvRateGroup(this, "Survivor", + G1YoungSurvRateNumRegionsSummary)) + // add here any more surv rate groups +{ + _recent_prev_end_times_for_all_gcs_sec->add(os::elapsedTime()); + _prev_collection_pause_end_ms = os::elapsedTime() * 1000.0; + + _par_last_ext_root_scan_times_ms = new double[_parallel_gc_threads]; + _par_last_mark_stack_scan_times_ms = new double[_parallel_gc_threads]; + _par_last_scan_only_times_ms = new double[_parallel_gc_threads]; + _par_last_scan_only_regions_scanned = new double[_parallel_gc_threads]; + + _par_last_update_rs_start_times_ms = new double[_parallel_gc_threads]; + _par_last_update_rs_times_ms = new double[_parallel_gc_threads]; + _par_last_update_rs_processed_buffers = new double[_parallel_gc_threads]; + + _par_last_scan_rs_start_times_ms = new double[_parallel_gc_threads]; + _par_last_scan_rs_times_ms = new double[_parallel_gc_threads]; + _par_last_scan_new_refs_times_ms = new double[_parallel_gc_threads]; + + _par_last_obj_copy_times_ms = new double[_parallel_gc_threads]; + + _par_last_termination_times_ms = new double[_parallel_gc_threads]; + + // we store the data from the first pass during popularity pauses + _pop_par_last_update_rs_start_times_ms = new double[_parallel_gc_threads]; + _pop_par_last_update_rs_times_ms = new double[_parallel_gc_threads]; + _pop_par_last_update_rs_processed_buffers = new double[_parallel_gc_threads]; + + _pop_par_last_scan_rs_start_times_ms = new double[_parallel_gc_threads]; + _pop_par_last_scan_rs_times_ms = new double[_parallel_gc_threads]; + + _pop_par_last_closure_app_times_ms = new double[_parallel_gc_threads]; + + // start conservatively + _expensive_region_limit_ms = 0.5 * (double) G1MaxPauseTimeMS; + + // + + int index; + if (ParallelGCThreads == 0) + index = 0; + else if (ParallelGCThreads > 8) + index = 7; + else + index = ParallelGCThreads - 1; + + _pending_card_diff_seq->add(0.0); + _rs_length_diff_seq->add(rs_length_diff_defaults[index]); + _cost_per_card_ms_seq->add(cost_per_card_ms_defaults[index]); + _cost_per_scan_only_region_ms_seq->add( + cost_per_scan_only_region_ms_defaults[index]); + _fully_young_cards_per_entry_ratio_seq->add( + fully_young_cards_per_entry_ratio_defaults[index]); + _cost_per_entry_ms_seq->add(cost_per_entry_ms_defaults[index]); + _cost_per_byte_ms_seq->add(cost_per_byte_ms_defaults[index]); + _constant_other_time_ms_seq->add(constant_other_time_ms_defaults[index]); + _young_other_cost_per_region_ms_seq->add( + young_other_cost_per_region_ms_defaults[index]); + _non_young_other_cost_per_region_ms_seq->add( + non_young_other_cost_per_region_ms_defaults[index]); + + // + + double time_slice = (double) G1TimeSliceMS / 1000.0; + double max_gc_time = (double) G1MaxPauseTimeMS / 1000.0; + guarantee(max_gc_time < time_slice, + "Max GC time should not be greater than the time slice"); + _mmu_tracker = new G1MMUTrackerQueue(time_slice, max_gc_time); + _sigma = (double) G1ConfidencePerc / 100.0; + + // start conservatively (around 50ms is about right) + _concurrent_mark_init_times_ms->add(0.05); + _concurrent_mark_remark_times_ms->add(0.05); + _concurrent_mark_cleanup_times_ms->add(0.20); + _tenuring_threshold = MaxTenuringThreshold; + + initialize_all(); +} + +// Increment "i", mod "len" +static void inc_mod(int& i, int len) { + i++; if (i == len) i = 0; +} + +void G1CollectorPolicy::initialize_flags() { + set_min_alignment(HeapRegion::GrainBytes); + set_max_alignment(GenRemSet::max_alignment_constraint(rem_set_name())); + CollectorPolicy::initialize_flags(); +} + +void G1CollectorPolicy::init() { + // Set aside an initial future to_space. + _g1 = G1CollectedHeap::heap(); + size_t regions = Universe::heap()->capacity() / HeapRegion::GrainBytes; + + assert(Heap_lock->owned_by_self(), "Locking discipline."); + + if (G1SteadyStateUsed < 50) { + vm_exit_during_initialization("G1SteadyStateUsed must be at least 50%."); + } + if (UseConcMarkSweepGC) { + vm_exit_during_initialization("-XX:+UseG1GC is incompatible with " + "-XX:+UseConcMarkSweepGC."); + } + + if (G1Gen) { + _in_young_gc_mode = true; + + if (G1YoungGenSize == 0) { + set_adaptive_young_list_length(true); + _young_list_fixed_length = 0; + } else { + set_adaptive_young_list_length(false); + _young_list_fixed_length = (G1YoungGenSize / HeapRegion::GrainBytes); + } + _free_regions_at_end_of_collection = _g1->free_regions(); + _scan_only_regions_at_end_of_collection = 0; + calculate_young_list_min_length(); + guarantee( _young_list_min_length == 0, "invariant, not enough info" ); + calculate_young_list_target_config(); + } else { + _young_list_fixed_length = 0; + _in_young_gc_mode = false; + } +} + +void G1CollectorPolicy::calculate_young_list_min_length() { + _young_list_min_length = 0; + + if (!adaptive_young_list_length()) + return; + + if (_alloc_rate_ms_seq->num() > 3) { + double now_sec = os::elapsedTime(); + double when_ms = _mmu_tracker->when_max_gc_sec(now_sec) * 1000.0; + double alloc_rate_ms = predict_alloc_rate_ms(); + int min_regions = (int) ceil(alloc_rate_ms * when_ms); + int current_region_num = (int) _g1->young_list_length(); + _young_list_min_length = min_regions + current_region_num; + } +} + +void G1CollectorPolicy::calculate_young_list_target_config() { + if (adaptive_young_list_length()) { + size_t rs_lengths = (size_t) get_new_prediction(_rs_lengths_seq); + calculate_young_list_target_config(rs_lengths); + } else { + if (full_young_gcs()) + _young_list_target_length = _young_list_fixed_length; + else + _young_list_target_length = _young_list_fixed_length / 2; + _young_list_target_length = MAX2(_young_list_target_length, (size_t)1); + size_t so_length = calculate_optimal_so_length(_young_list_target_length); + guarantee( so_length < _young_list_target_length, "invariant" ); + _young_list_so_prefix_length = so_length; + } +} + +// This method calculate the optimal scan-only set for a fixed young +// gen size. I couldn't work out how to reuse the more elaborate one, +// i.e. calculate_young_list_target_config(rs_length), as the loops are +// fundamentally different (the other one finds a config for different +// S-O lengths, whereas here we need to do the opposite). +size_t G1CollectorPolicy::calculate_optimal_so_length( + size_t young_list_length) { + if (!G1UseScanOnlyPrefix) + return 0; + + if (_all_pause_times_ms->num() < 3) { + // we won't use a scan-only set at the beginning to allow the rest + // of the predictors to warm up + return 0; + } + + if (_cost_per_scan_only_region_ms_seq->num() < 3) { + // then, we'll only set the S-O set to 1 for a little bit of time, + // to get enough information on the scanning cost + return 1; + } + + size_t pending_cards = (size_t) get_new_prediction(_pending_cards_seq); + size_t rs_lengths = (size_t) get_new_prediction(_rs_lengths_seq); + size_t adj_rs_lengths = rs_lengths + predict_rs_length_diff(); + size_t scanned_cards; + if (full_young_gcs()) + scanned_cards = predict_young_card_num(adj_rs_lengths); + else + scanned_cards = predict_non_young_card_num(adj_rs_lengths); + double base_time_ms = predict_base_elapsed_time_ms(pending_cards, + scanned_cards); + + size_t so_length = 0; + double max_gc_eff = 0.0; + for (size_t i = 0; i < young_list_length; ++i) { + double gc_eff = 0.0; + double pause_time_ms = 0.0; + predict_gc_eff(young_list_length, i, base_time_ms, + &gc_eff, &pause_time_ms); + if (gc_eff > max_gc_eff) { + max_gc_eff = gc_eff; + so_length = i; + } + } + + // set it to 95% of the optimal to make sure we sample the "area" + // around the optimal length to get up-to-date survival rate data + return so_length * 950 / 1000; +} + +// This is a really cool piece of code! It finds the best +// target configuration (young length / scan-only prefix length) so +// that GC efficiency is maximized and that we also meet a pause +// time. It's a triple nested loop. These loops are explained below +// from the inside-out :-) +// +// (a) The innermost loop will try to find the optimal young length +// for a fixed S-O length. It uses a binary search to speed up the +// process. We assume that, for a fixed S-O length, as we add more +// young regions to the CSet, the GC efficiency will only go up (I'll +// skip the proof). So, using a binary search to optimize this process +// makes perfect sense. +// +// (b) The middle loop will fix the S-O length before calling the +// innermost one. It will vary it between two parameters, increasing +// it by a given increment. +// +// (c) The outermost loop will call the middle loop three times. +// (1) The first time it will explore all possible S-O length values +// from 0 to as large as it can get, using a coarse increment (to +// quickly "home in" to where the optimal seems to be). +// (2) The second time it will explore the values around the optimal +// that was found by the first iteration using a fine increment. +// (3) Once the optimal config has been determined by the second +// iteration, we'll redo the calculation, but setting the S-O length +// to 95% of the optimal to make sure we sample the "area" +// around the optimal length to get up-to-date survival rate data +// +// Termination conditions for the iterations are several: the pause +// time is over the limit, we do not have enough to-space, etc. + +void G1CollectorPolicy::calculate_young_list_target_config(size_t rs_lengths) { + guarantee( adaptive_young_list_length(), "pre-condition" ); + + double start_time_sec = os::elapsedTime(); + size_t min_reserve_perc = MAX2((size_t)2, (size_t)G1MinReservePerc); + min_reserve_perc = MIN2((size_t) 50, min_reserve_perc); + size_t reserve_regions = + (size_t) ((double) min_reserve_perc * (double) _g1->n_regions() / 100.0); + + if (full_young_gcs() && _free_regions_at_end_of_collection > 0) { + // we are in fully-young mode and there are free regions in the heap + + size_t min_so_length = 0; + size_t max_so_length = 0; + + if (G1UseScanOnlyPrefix) { + if (_all_pause_times_ms->num() < 3) { + // we won't use a scan-only set at the beginning to allow the rest + // of the predictors to warm up + min_so_length = 0; + max_so_length = 0; + } else if (_cost_per_scan_only_region_ms_seq->num() < 3) { + // then, we'll only set the S-O set to 1 for a little bit of time, + // to get enough information on the scanning cost + min_so_length = 1; + max_so_length = 1; + } else if (_in_marking_window || _last_full_young_gc) { + // no S-O prefix during a marking phase either, as at the end + // of the marking phase we'll have to use a very small young + // length target to fill up the rest of the CSet with + // non-young regions and, if we have lots of scan-only regions + // left-over, we will not be able to add any more non-young + // regions. + min_so_length = 0; + max_so_length = 0; + } else { + // this is the common case; we'll never reach the maximum, we + // one of the end conditions will fire well before that + // (hopefully!) + min_so_length = 0; + max_so_length = _free_regions_at_end_of_collection - 1; + } + } else { + // no S-O prefix, as the switch is not set, but we still need to + // do one iteration to calculate the best young target that + // meets the pause time; this way we reuse the same code instead + // of replicating it + min_so_length = 0; + max_so_length = 0; + } + + double target_pause_time_ms = _mmu_tracker->max_gc_time() * 1000.0; + size_t pending_cards = (size_t) get_new_prediction(_pending_cards_seq); + size_t adj_rs_lengths = rs_lengths + predict_rs_length_diff(); + size_t scanned_cards; + if (full_young_gcs()) + scanned_cards = predict_young_card_num(adj_rs_lengths); + else + scanned_cards = predict_non_young_card_num(adj_rs_lengths); + // calculate this once, so that we don't have to recalculate it in + // the innermost loop + double base_time_ms = predict_base_elapsed_time_ms(pending_cards, + scanned_cards); + + // the result + size_t final_young_length = 0; + size_t final_so_length = 0; + double final_gc_eff = 0.0; + // we'll also keep track of how many times we go into the inner loop + // this is for profiling reasons + size_t calculations = 0; + + // this determines which of the three iterations the outer loop is in + typedef enum { + pass_type_coarse, + pass_type_fine, + pass_type_final + } pass_type_t; + + // range of the outer loop's iteration + size_t from_so_length = min_so_length; + size_t to_so_length = max_so_length; + guarantee( from_so_length <= to_so_length, "invariant" ); + + // this will keep the S-O length that's found by the second + // iteration of the outer loop; we'll keep it just in case the third + // iteration fails to find something + size_t fine_so_length = 0; + + // the increment step for the coarse (first) iteration + size_t so_coarse_increments = 5; + + // the common case, we'll start with the coarse iteration + pass_type_t pass = pass_type_coarse; + size_t so_length_incr = so_coarse_increments; + + if (from_so_length == to_so_length) { + // not point in doing the coarse iteration, we'll go directly into + // the fine one (we essentially trying to find the optimal young + // length for a fixed S-O length). + so_length_incr = 1; + pass = pass_type_final; + } else if (to_so_length - from_so_length < 3 * so_coarse_increments) { + // again, the range is too short so no point in foind the coarse + // iteration either + so_length_incr = 1; + pass = pass_type_fine; + } + + bool done = false; + // this is the outermost loop + while (!done) { +#if 0 + // leave this in for debugging, just in case + gclog_or_tty->print_cr("searching between " SIZE_FORMAT " and " SIZE_FORMAT + ", incr " SIZE_FORMAT ", pass %s", + from_so_length, to_so_length, so_length_incr, + (pass == pass_type_coarse) ? "coarse" : + (pass == pass_type_fine) ? "fine" : "final"); +#endif // 0 + + size_t so_length = from_so_length; + size_t init_free_regions = + MAX2((size_t)0, + _free_regions_at_end_of_collection + + _scan_only_regions_at_end_of_collection - reserve_regions); + + // this determines whether a configuration was found + bool gc_eff_set = false; + // this is the middle loop + while (so_length <= to_so_length) { + // base time, which excludes region-related time; again we + // calculate it once to avoid recalculating it in the + // innermost loop + double base_time_with_so_ms = + base_time_ms + predict_scan_only_time_ms(so_length); + // it's already over the pause target, go around + if (base_time_with_so_ms > target_pause_time_ms) + break; + + size_t starting_young_length = so_length+1; + + // we make sure that the short young length that makes sense + // (one more than the S-O length) is feasible + size_t min_young_length = starting_young_length; + double min_gc_eff; + bool min_ok; + ++calculations; + min_ok = predict_gc_eff(min_young_length, so_length, + base_time_with_so_ms, + init_free_regions, target_pause_time_ms, + &min_gc_eff); + + if (min_ok) { + // the shortest young length is indeed feasible; we'll know + // set up the max young length and we'll do a binary search + // between min_young_length and max_young_length + size_t max_young_length = _free_regions_at_end_of_collection - 1; + double max_gc_eff = 0.0; + bool max_ok = false; + + // the innermost loop! (finally!) + while (max_young_length > min_young_length) { + // we'll make sure that min_young_length is always at a + // feasible config + guarantee( min_ok, "invariant" ); + + ++calculations; + max_ok = predict_gc_eff(max_young_length, so_length, + base_time_with_so_ms, + init_free_regions, target_pause_time_ms, + &max_gc_eff); + + size_t diff = (max_young_length - min_young_length) / 2; + if (max_ok) { + min_young_length = max_young_length; + min_gc_eff = max_gc_eff; + min_ok = true; + } + max_young_length = min_young_length + diff; + } + + // the innermost loop found a config + guarantee( min_ok, "invariant" ); + if (min_gc_eff > final_gc_eff) { + // it's the best config so far, so we'll keep it + final_gc_eff = min_gc_eff; + final_young_length = min_young_length; + final_so_length = so_length; + gc_eff_set = true; + } + } + + // incremental the fixed S-O length and go around + so_length += so_length_incr; + } + + // this is the end of the outermost loop and we need to decide + // what to do during the next iteration + if (pass == pass_type_coarse) { + // we just did the coarse pass (first iteration) + + if (!gc_eff_set) + // we didn't find a feasible config so we'll just bail out; of + // course, it might be the case that we missed it; but I'd say + // it's a bit unlikely + done = true; + else { + // We did find a feasible config with optimal GC eff during + // the first pass. So the second pass we'll only consider the + // S-O lengths around that config with a fine increment. + + guarantee( so_length_incr == so_coarse_increments, "invariant" ); + guarantee( final_so_length >= min_so_length, "invariant" ); + +#if 0 + // leave this in for debugging, just in case + gclog_or_tty->print_cr(" coarse pass: SO length " SIZE_FORMAT, + final_so_length); +#endif // 0 + + from_so_length = + (final_so_length - min_so_length > so_coarse_increments) ? + final_so_length - so_coarse_increments + 1 : min_so_length; + to_so_length = + (max_so_length - final_so_length > so_coarse_increments) ? + final_so_length + so_coarse_increments - 1 : max_so_length; + + pass = pass_type_fine; + so_length_incr = 1; + } + } else if (pass == pass_type_fine) { + // we just finished the second pass + + if (!gc_eff_set) { + // we didn't find a feasible config (yes, it's possible; + // notice that, sometimes, we go directly into the fine + // iteration and skip the coarse one) so we bail out + done = true; + } else { + // We did find a feasible config with optimal GC eff + guarantee( so_length_incr == 1, "invariant" ); + + if (final_so_length == 0) { + // The config is of an empty S-O set, so we'll just bail out + done = true; + } else { + // we'll go around once more, setting the S-O length to 95% + // of the optimal + size_t new_so_length = 950 * final_so_length / 1000; + +#if 0 + // leave this in for debugging, just in case + gclog_or_tty->print_cr(" fine pass: SO length " SIZE_FORMAT + ", setting it to " SIZE_FORMAT, + final_so_length, new_so_length); +#endif // 0 + + from_so_length = new_so_length; + to_so_length = new_so_length; + fine_so_length = final_so_length; + + pass = pass_type_final; + } + } + } else if (pass == pass_type_final) { + // we just finished the final (third) pass + + if (!gc_eff_set) + // we didn't find a feasible config, so we'll just use the one + // we found during the second pass, which we saved + final_so_length = fine_so_length; + + // and we're done! + done = true; + } else { + guarantee( false, "should never reach here" ); + } + + // we now go around the outermost loop + } + + // we should have at least one region in the target young length + _young_list_target_length = MAX2((size_t) 1, final_young_length); + if (final_so_length >= final_young_length) + // and we need to ensure that the S-O length is not greater than + // the target young length (this is being a bit careful) + final_so_length = 0; + _young_list_so_prefix_length = final_so_length; + guarantee( !_in_marking_window || !_last_full_young_gc || + _young_list_so_prefix_length == 0, "invariant" ); + + // let's keep an eye of how long we spend on this calculation + // right now, I assume that we'll print it when we need it; we + // should really adde it to the breakdown of a pause + double end_time_sec = os::elapsedTime(); + double elapsed_time_ms = (end_time_sec - start_time_sec) * 1000.0; + +#if 0 + // leave this in for debugging, just in case + gclog_or_tty->print_cr("target = %1.1lf ms, young = " SIZE_FORMAT + ", SO = " SIZE_FORMAT ", " + "elapsed %1.2lf ms, calcs: " SIZE_FORMAT " (%s%s) " + SIZE_FORMAT SIZE_FORMAT, + target_pause_time_ms, + _young_list_target_length - _young_list_so_prefix_length, + _young_list_so_prefix_length, + elapsed_time_ms, + calculations, + full_young_gcs() ? "full" : "partial", + should_initiate_conc_mark() ? " i-m" : "", + in_marking_window(), + in_marking_window_im()); +#endif // 0 + + if (_young_list_target_length < _young_list_min_length) { + // bummer; this means that, if we do a pause when the optimal + // config dictates, we'll violate the pause spacing target (the + // min length was calculate based on the application's current + // alloc rate); + + // so, we have to bite the bullet, and allocate the minimum + // number. We'll violate our target, but we just can't meet it. + + size_t so_length = 0; + // a note further up explains why we do not want an S-O length + // during marking + if (!_in_marking_window && !_last_full_young_gc) + // but we can still try to see whether we can find an optimal + // S-O length + so_length = calculate_optimal_so_length(_young_list_min_length); + +#if 0 + // leave this in for debugging, just in case + gclog_or_tty->print_cr("adjusted target length from " + SIZE_FORMAT " to " SIZE_FORMAT + ", SO " SIZE_FORMAT, + _young_list_target_length, _young_list_min_length, + so_length); +#endif // 0 + + _young_list_target_length = + MAX2(_young_list_min_length, (size_t)1); + _young_list_so_prefix_length = so_length; + } + } else { + // we are in a partially-young mode or we've run out of regions (due + // to evacuation failure) + +#if 0 + // leave this in for debugging, just in case + gclog_or_tty->print_cr("(partial) setting target to " SIZE_FORMAT + ", SO " SIZE_FORMAT, + _young_list_min_length, 0); +#endif // 0 + + // we'll do the pause as soon as possible and with no S-O prefix + // (see above for the reasons behind the latter) + _young_list_target_length = + MAX2(_young_list_min_length, (size_t) 1); + _young_list_so_prefix_length = 0; + } + + _rs_lengths_prediction = rs_lengths; +} + +// This is used by: calculate_optimal_so_length(length). It returns +// the GC eff and predicted pause time for a particular config +void +G1CollectorPolicy::predict_gc_eff(size_t young_length, + size_t so_length, + double base_time_ms, + double* ret_gc_eff, + double* ret_pause_time_ms) { + double so_time_ms = predict_scan_only_time_ms(so_length); + double accum_surv_rate_adj = 0.0; + if (so_length > 0) + accum_surv_rate_adj = accum_yg_surv_rate_pred((int)(so_length - 1)); + double accum_surv_rate = + accum_yg_surv_rate_pred((int)(young_length - 1)) - accum_surv_rate_adj; + size_t bytes_to_copy = + (size_t) (accum_surv_rate * (double) HeapRegion::GrainBytes); + double copy_time_ms = predict_object_copy_time_ms(bytes_to_copy); + double young_other_time_ms = + predict_young_other_time_ms(young_length - so_length); + double pause_time_ms = + base_time_ms + so_time_ms + copy_time_ms + young_other_time_ms; + size_t reclaimed_bytes = + (young_length - so_length) * HeapRegion::GrainBytes - bytes_to_copy; + double gc_eff = (double) reclaimed_bytes / pause_time_ms; + + *ret_gc_eff = gc_eff; + *ret_pause_time_ms = pause_time_ms; +} + +// This is used by: calculate_young_list_target_config(rs_length). It +// returns the GC eff of a particular config. It returns false if that +// config violates any of the end conditions of the search in the +// calling method, or true upon success. The end conditions were put +// here since it's called twice and it was best not to replicate them +// in the caller. Also, passing the parameteres avoids having to +// recalculate them in the innermost loop. +bool +G1CollectorPolicy::predict_gc_eff(size_t young_length, + size_t so_length, + double base_time_with_so_ms, + size_t init_free_regions, + double target_pause_time_ms, + double* ret_gc_eff) { + *ret_gc_eff = 0.0; + + if (young_length >= init_free_regions) + // end condition 1: not enough space for the young regions + return false; + + double accum_surv_rate_adj = 0.0; + if (so_length > 0) + accum_surv_rate_adj = accum_yg_surv_rate_pred((int)(so_length - 1)); + double accum_surv_rate = + accum_yg_surv_rate_pred((int)(young_length - 1)) - accum_surv_rate_adj; + size_t bytes_to_copy = + (size_t) (accum_surv_rate * (double) HeapRegion::GrainBytes); + double copy_time_ms = predict_object_copy_time_ms(bytes_to_copy); + double young_other_time_ms = + predict_young_other_time_ms(young_length - so_length); + double pause_time_ms = + base_time_with_so_ms + copy_time_ms + young_other_time_ms; + + if (pause_time_ms > target_pause_time_ms) + // end condition 2: over the target pause time + return false; + + size_t reclaimed_bytes = + (young_length - so_length) * HeapRegion::GrainBytes - bytes_to_copy; + size_t free_bytes = + (init_free_regions - young_length) * HeapRegion::GrainBytes; + + if ((2.0 + sigma()) * (double) bytes_to_copy > (double) free_bytes) + // end condition 3: out of to-space (conservatively) + return false; + + // success! + double gc_eff = (double) reclaimed_bytes / pause_time_ms; + *ret_gc_eff = gc_eff; + + return true; +} + +void G1CollectorPolicy::check_prediction_validity() { + guarantee( adaptive_young_list_length(), "should not call this otherwise" ); + + size_t rs_lengths = _g1->young_list_sampled_rs_lengths(); + if (rs_lengths > _rs_lengths_prediction) { + // add 10% to avoid having to recalculate often + size_t rs_lengths_prediction = rs_lengths * 1100 / 1000; + calculate_young_list_target_config(rs_lengths_prediction); + } +} + +HeapWord* G1CollectorPolicy::mem_allocate_work(size_t size, + bool is_tlab, + bool* gc_overhead_limit_was_exceeded) { + guarantee(false, "Not using this policy feature yet."); + return NULL; +} + +// This method controls how a collector handles one or more +// of its generations being fully allocated. +HeapWord* G1CollectorPolicy::satisfy_failed_allocation(size_t size, + bool is_tlab) { + guarantee(false, "Not using this policy feature yet."); + return NULL; +} + + +#ifndef PRODUCT +bool G1CollectorPolicy::verify_young_ages() { + HeapRegion* head = _g1->young_list_first_region(); + return + verify_young_ages(head, _short_lived_surv_rate_group); + // also call verify_young_ages on any additional surv rate groups +} + +bool +G1CollectorPolicy::verify_young_ages(HeapRegion* head, + SurvRateGroup *surv_rate_group) { + guarantee( surv_rate_group != NULL, "pre-condition" ); + + const char* name = surv_rate_group->name(); + bool ret = true; + int prev_age = -1; + + for (HeapRegion* curr = head; + curr != NULL; + curr = curr->get_next_young_region()) { + SurvRateGroup* group = curr->surv_rate_group(); + if (group == NULL && !curr->is_survivor()) { + gclog_or_tty->print_cr("## %s: encountered NULL surv_rate_group", name); + ret = false; + } + + if (surv_rate_group == group) { + int age = curr->age_in_surv_rate_group(); + + if (age < 0) { + gclog_or_tty->print_cr("## %s: encountered negative age", name); + ret = false; + } + + if (age <= prev_age) { + gclog_or_tty->print_cr("## %s: region ages are not strictly increasing " + "(%d, %d)", name, age, prev_age); + ret = false; + } + prev_age = age; + } + } + + return ret; +} +#endif // PRODUCT + +void G1CollectorPolicy::record_full_collection_start() { + _cur_collection_start_sec = os::elapsedTime(); + // Release the future to-space so that it is available for compaction into. + _g1->set_full_collection(); +} + +void G1CollectorPolicy::record_full_collection_end() { + // Consider this like a collection pause for the purposes of allocation + // since last pause. + double end_sec = os::elapsedTime(); + double full_gc_time_sec = end_sec - _cur_collection_start_sec; + double full_gc_time_ms = full_gc_time_sec * 1000.0; + + checkpoint_conc_overhead(); + + _all_full_gc_times_ms->add(full_gc_time_ms); + + update_recent_gc_times(end_sec, full_gc_time_sec); + + _g1->clear_full_collection(); + + // "Nuke" the heuristics that control the fully/partially young GC + // transitions and make sure we start with fully young GCs after the + // Full GC. + set_full_young_gcs(true); + _last_full_young_gc = false; + _should_revert_to_full_young_gcs = false; + _should_initiate_conc_mark = false; + _known_garbage_bytes = 0; + _known_garbage_ratio = 0.0; + _in_marking_window = false; + _in_marking_window_im = false; + + _short_lived_surv_rate_group->record_scan_only_prefix(0); + _short_lived_surv_rate_group->start_adding_regions(); + // also call this on any additional surv rate groups + + _prev_region_num_young = _region_num_young; + _prev_region_num_tenured = _region_num_tenured; + + _free_regions_at_end_of_collection = _g1->free_regions(); + _scan_only_regions_at_end_of_collection = 0; + calculate_young_list_min_length(); + calculate_young_list_target_config(); + } + +void G1CollectorPolicy::record_pop_compute_rc_start() { + _pop_compute_rc_start = os::elapsedTime(); +} +void G1CollectorPolicy::record_pop_compute_rc_end() { + double ms = (os::elapsedTime() - _pop_compute_rc_start)*1000.0; + _cur_popular_compute_rc_time_ms = ms; + _pop_compute_rc_start = 0.0; +} +void G1CollectorPolicy::record_pop_evac_start() { + _pop_evac_start = os::elapsedTime(); +} +void G1CollectorPolicy::record_pop_evac_end() { + double ms = (os::elapsedTime() - _pop_evac_start)*1000.0; + _cur_popular_evac_time_ms = ms; + _pop_evac_start = 0.0; +} + +void G1CollectorPolicy::record_before_bytes(size_t bytes) { + _bytes_in_to_space_before_gc += bytes; +} + +void G1CollectorPolicy::record_after_bytes(size_t bytes) { + _bytes_in_to_space_after_gc += bytes; +} + +void G1CollectorPolicy::record_stop_world_start() { + _stop_world_start = os::elapsedTime(); +} + +void G1CollectorPolicy::record_collection_pause_start(double start_time_sec, + size_t start_used) { + if (PrintGCDetails) { + gclog_or_tty->stamp(PrintGCTimeStamps); + gclog_or_tty->print("[GC pause"); + if (in_young_gc_mode()) + gclog_or_tty->print(" (%s)", full_young_gcs() ? "young" : "partial"); + } + + assert(_g1->used_regions() == _g1->recalculate_used_regions(), + "sanity"); + + double s_w_t_ms = (start_time_sec - _stop_world_start) * 1000.0; + _all_stop_world_times_ms->add(s_w_t_ms); + _stop_world_start = 0.0; + + _cur_collection_start_sec = start_time_sec; + _cur_collection_pause_used_at_start_bytes = start_used; + _cur_collection_pause_used_regions_at_start = _g1->used_regions(); + _pending_cards = _g1->pending_card_num(); + _max_pending_cards = _g1->max_pending_card_num(); + + _bytes_in_to_space_before_gc = 0; + _bytes_in_to_space_after_gc = 0; + _bytes_in_collection_set_before_gc = 0; + +#ifdef DEBUG + // initialise these to something well known so that we can spot + // if they are not set properly + + for (int i = 0; i < _parallel_gc_threads; ++i) { + _par_last_ext_root_scan_times_ms[i] = -666.0; + _par_last_mark_stack_scan_times_ms[i] = -666.0; + _par_last_scan_only_times_ms[i] = -666.0; + _par_last_scan_only_regions_scanned[i] = -666.0; + _par_last_update_rs_start_times_ms[i] = -666.0; + _par_last_update_rs_times_ms[i] = -666.0; + _par_last_update_rs_processed_buffers[i] = -666.0; + _par_last_scan_rs_start_times_ms[i] = -666.0; + _par_last_scan_rs_times_ms[i] = -666.0; + _par_last_scan_new_refs_times_ms[i] = -666.0; + _par_last_obj_copy_times_ms[i] = -666.0; + _par_last_termination_times_ms[i] = -666.0; + + _pop_par_last_update_rs_start_times_ms[i] = -666.0; + _pop_par_last_update_rs_times_ms[i] = -666.0; + _pop_par_last_update_rs_processed_buffers[i] = -666.0; + _pop_par_last_scan_rs_start_times_ms[i] = -666.0; + _pop_par_last_scan_rs_times_ms[i] = -666.0; + _pop_par_last_closure_app_times_ms[i] = -666.0; + } +#endif + + for (int i = 0; i < _aux_num; ++i) { + _cur_aux_times_ms[i] = 0.0; + _cur_aux_times_set[i] = false; + } + + _satb_drain_time_set = false; + _last_satb_drain_processed_buffers = -1; + + if (in_young_gc_mode()) + _last_young_gc_full = false; + + + // do that for any other surv rate groups + _short_lived_surv_rate_group->stop_adding_regions(); + size_t short_lived_so_length = _young_list_so_prefix_length; + _short_lived_surv_rate_group->record_scan_only_prefix(short_lived_so_length); + tag_scan_only(short_lived_so_length); + + assert( verify_young_ages(), "region age verification" ); +} + +void G1CollectorPolicy::tag_scan_only(size_t short_lived_scan_only_length) { + // done in a way that it can be extended for other surv rate groups too... + + HeapRegion* head = _g1->young_list_first_region(); + bool finished_short_lived = (short_lived_scan_only_length == 0); + + if (finished_short_lived) + return; + + for (HeapRegion* curr = head; + curr != NULL; + curr = curr->get_next_young_region()) { + SurvRateGroup* surv_rate_group = curr->surv_rate_group(); + int age = curr->age_in_surv_rate_group(); + + if (surv_rate_group == _short_lived_surv_rate_group) { + if ((size_t)age < short_lived_scan_only_length) + curr->set_scan_only(); + else + finished_short_lived = true; + } + + + if (finished_short_lived) + return; + } + + guarantee( false, "we should never reach here" ); +} + +void G1CollectorPolicy::record_popular_pause_preamble_start() { + _cur_popular_preamble_start_ms = os::elapsedTime() * 1000.0; +} + +void G1CollectorPolicy::record_popular_pause_preamble_end() { + _cur_popular_preamble_time_ms = + (os::elapsedTime() * 1000.0) - _cur_popular_preamble_start_ms; + + // copy the recorded statistics of the first pass to temporary arrays + for (int i = 0; i < _parallel_gc_threads; ++i) { + _pop_par_last_update_rs_start_times_ms[i] = _par_last_update_rs_start_times_ms[i]; + _pop_par_last_update_rs_times_ms[i] = _par_last_update_rs_times_ms[i]; + _pop_par_last_update_rs_processed_buffers[i] = _par_last_update_rs_processed_buffers[i]; + _pop_par_last_scan_rs_start_times_ms[i] = _par_last_scan_rs_start_times_ms[i]; + _pop_par_last_scan_rs_times_ms[i] = _par_last_scan_rs_times_ms[i]; + _pop_par_last_closure_app_times_ms[i] = _par_last_obj_copy_times_ms[i]; + } +} + +void G1CollectorPolicy::record_mark_closure_time(double mark_closure_time_ms) { + _mark_closure_time_ms = mark_closure_time_ms; +} + +void G1CollectorPolicy::record_concurrent_mark_init_start() { + _mark_init_start_sec = os::elapsedTime(); + guarantee(!in_young_gc_mode(), "should not do be here in young GC mode"); +} + +void G1CollectorPolicy::record_concurrent_mark_init_end_pre(double + mark_init_elapsed_time_ms) { + _during_marking = true; + _should_initiate_conc_mark = false; + _cur_mark_stop_world_time_ms = mark_init_elapsed_time_ms; +} + +void G1CollectorPolicy::record_concurrent_mark_init_end() { + double end_time_sec = os::elapsedTime(); + double elapsed_time_ms = (end_time_sec - _mark_init_start_sec) * 1000.0; + _concurrent_mark_init_times_ms->add(elapsed_time_ms); + checkpoint_conc_overhead(); + record_concurrent_mark_init_end_pre(elapsed_time_ms); + + _mmu_tracker->add_pause(_mark_init_start_sec, end_time_sec, true); +} + +void G1CollectorPolicy::record_concurrent_mark_remark_start() { + _mark_remark_start_sec = os::elapsedTime(); + _during_marking = false; +} + +void G1CollectorPolicy::record_concurrent_mark_remark_end() { + double end_time_sec = os::elapsedTime(); + double elapsed_time_ms = (end_time_sec - _mark_remark_start_sec)*1000.0; + checkpoint_conc_overhead(); + _concurrent_mark_remark_times_ms->add(elapsed_time_ms); + _cur_mark_stop_world_time_ms += elapsed_time_ms; + _prev_collection_pause_end_ms += elapsed_time_ms; + + _mmu_tracker->add_pause(_mark_remark_start_sec, end_time_sec, true); +} + +void G1CollectorPolicy::record_concurrent_mark_cleanup_start() { + _mark_cleanup_start_sec = os::elapsedTime(); +} + +void +G1CollectorPolicy::record_concurrent_mark_cleanup_end(size_t freed_bytes, + size_t max_live_bytes) { + record_concurrent_mark_cleanup_end_work1(freed_bytes, max_live_bytes); + record_concurrent_mark_cleanup_end_work2(); +} + +void +G1CollectorPolicy:: +record_concurrent_mark_cleanup_end_work1(size_t freed_bytes, + size_t max_live_bytes) { + if (_n_marks < 2) _n_marks++; + if (G1PolicyVerbose > 0) + gclog_or_tty->print_cr("At end of marking, max_live is " SIZE_FORMAT " MB " + " (of " SIZE_FORMAT " MB heap).", + max_live_bytes/M, _g1->capacity()/M); +} + +// The important thing about this is that it includes "os::elapsedTime". +void G1CollectorPolicy::record_concurrent_mark_cleanup_end_work2() { + checkpoint_conc_overhead(); + double end_time_sec = os::elapsedTime(); + double elapsed_time_ms = (end_time_sec - _mark_cleanup_start_sec)*1000.0; + _concurrent_mark_cleanup_times_ms->add(elapsed_time_ms); + _cur_mark_stop_world_time_ms += elapsed_time_ms; + _prev_collection_pause_end_ms += elapsed_time_ms; + + _mmu_tracker->add_pause(_mark_cleanup_start_sec, end_time_sec, true); + + _num_markings++; + + // We did a marking, so reset the "since_last_mark" variables. + double considerConcMarkCost = 1.0; + // If there are available processors, concurrent activity is free... + if (Threads::number_of_non_daemon_threads() * 2 < + os::active_processor_count()) { + considerConcMarkCost = 0.0; + } + _n_pauses_at_mark_end = _n_pauses; + _n_marks_since_last_pause++; + _conc_mark_initiated = false; +} + +void +G1CollectorPolicy::record_concurrent_mark_cleanup_completed() { + if (in_young_gc_mode()) { + _should_revert_to_full_young_gcs = false; + _last_full_young_gc = true; + _in_marking_window = false; + if (adaptive_young_list_length()) + calculate_young_list_target_config(); + } +} + +void G1CollectorPolicy::record_concurrent_pause() { + if (_stop_world_start > 0.0) { + double yield_ms = (os::elapsedTime() - _stop_world_start) * 1000.0; + _all_yield_times_ms->add(yield_ms); + } +} + +void G1CollectorPolicy::record_concurrent_pause_end() { +} + +void G1CollectorPolicy::record_collection_pause_end_CH_strong_roots() { + _cur_CH_strong_roots_end_sec = os::elapsedTime(); + _cur_CH_strong_roots_dur_ms = + (_cur_CH_strong_roots_end_sec - _cur_collection_start_sec) * 1000.0; +} + +void G1CollectorPolicy::record_collection_pause_end_G1_strong_roots() { + _cur_G1_strong_roots_end_sec = os::elapsedTime(); + _cur_G1_strong_roots_dur_ms = + (_cur_G1_strong_roots_end_sec - _cur_CH_strong_roots_end_sec) * 1000.0; +} + +template +T sum_of(T* sum_arr, int start, int n, int N) { + T sum = (T)0; + for (int i = 0; i < n; i++) { + int j = (start + i) % N; + sum += sum_arr[j]; + } + return sum; +} + +void G1CollectorPolicy::print_par_stats (int level, + const char* str, + double* data, + bool summary) { + double min = data[0], max = data[0]; + double total = 0.0; + int j; + for (j = 0; j < level; ++j) + gclog_or_tty->print(" "); + gclog_or_tty->print("[%s (ms):", str); + for (uint i = 0; i < ParallelGCThreads; ++i) { + double val = data[i]; + if (val < min) + min = val; + if (val > max) + max = val; + total += val; + gclog_or_tty->print(" %3.1lf", val); + } + if (summary) { + gclog_or_tty->print_cr(""); + double avg = total / (double) ParallelGCThreads; + gclog_or_tty->print(" "); + for (j = 0; j < level; ++j) + gclog_or_tty->print(" "); + gclog_or_tty->print("Avg: %5.1lf, Min: %5.1lf, Max: %5.1lf", + avg, min, max); + } + gclog_or_tty->print_cr("]"); +} + +void G1CollectorPolicy::print_par_buffers (int level, + const char* str, + double* data, + bool summary) { + double min = data[0], max = data[0]; + double total = 0.0; + int j; + for (j = 0; j < level; ++j) + gclog_or_tty->print(" "); + gclog_or_tty->print("[%s :", str); + for (uint i = 0; i < ParallelGCThreads; ++i) { + double val = data[i]; + if (val < min) + min = val; + if (val > max) + max = val; + total += val; + gclog_or_tty->print(" %d", (int) val); + } + if (summary) { + gclog_or_tty->print_cr(""); + double avg = total / (double) ParallelGCThreads; + gclog_or_tty->print(" "); + for (j = 0; j < level; ++j) + gclog_or_tty->print(" "); + gclog_or_tty->print("Sum: %d, Avg: %d, Min: %d, Max: %d", + (int)total, (int)avg, (int)min, (int)max); + } + gclog_or_tty->print_cr("]"); +} + +void G1CollectorPolicy::print_stats (int level, + const char* str, + double value) { + for (int j = 0; j < level; ++j) + gclog_or_tty->print(" "); + gclog_or_tty->print_cr("[%s: %5.1lf ms]", str, value); +} + +void G1CollectorPolicy::print_stats (int level, + const char* str, + int value) { + for (int j = 0; j < level; ++j) + gclog_or_tty->print(" "); + gclog_or_tty->print_cr("[%s: %d]", str, value); +} + +double G1CollectorPolicy::avg_value (double* data) { + if (ParallelGCThreads > 0) { + double ret = 0.0; + for (uint i = 0; i < ParallelGCThreads; ++i) + ret += data[i]; + return ret / (double) ParallelGCThreads; + } else { + return data[0]; + } +} + +double G1CollectorPolicy::max_value (double* data) { + if (ParallelGCThreads > 0) { + double ret = data[0]; + for (uint i = 1; i < ParallelGCThreads; ++i) + if (data[i] > ret) + ret = data[i]; + return ret; + } else { + return data[0]; + } +} + +double G1CollectorPolicy::sum_of_values (double* data) { + if (ParallelGCThreads > 0) { + double sum = 0.0; + for (uint i = 0; i < ParallelGCThreads; i++) + sum += data[i]; + return sum; + } else { + return data[0]; + } +} + +double G1CollectorPolicy::max_sum (double* data1, + double* data2) { + double ret = data1[0] + data2[0]; + + if (ParallelGCThreads > 0) { + for (uint i = 1; i < ParallelGCThreads; ++i) { + double data = data1[i] + data2[i]; + if (data > ret) + ret = data; + } + } + return ret; +} + +// Anything below that is considered to be zero +#define MIN_TIMER_GRANULARITY 0.0000001 + +void G1CollectorPolicy::record_collection_pause_end(bool popular, + bool abandoned) { + double end_time_sec = os::elapsedTime(); + double elapsed_ms = _last_pause_time_ms; + bool parallel = ParallelGCThreads > 0; + double evac_ms = (end_time_sec - _cur_G1_strong_roots_end_sec) * 1000.0; + size_t rs_size = + _cur_collection_pause_used_regions_at_start - collection_set_size(); + size_t cur_used_bytes = _g1->used(); + assert(cur_used_bytes == _g1->recalculate_used(), "It should!"); + bool last_pause_included_initial_mark = false; + +#ifndef PRODUCT + if (G1YoungSurvRateVerbose) { + gclog_or_tty->print_cr(""); + _short_lived_surv_rate_group->print(); + // do that for any other surv rate groups too + } +#endif // PRODUCT + + checkpoint_conc_overhead(); + + if (in_young_gc_mode()) { + last_pause_included_initial_mark = _should_initiate_conc_mark; + if (last_pause_included_initial_mark) + record_concurrent_mark_init_end_pre(0.0); + + size_t min_used_targ = + (_g1->capacity() / 100) * (G1SteadyStateUsed - G1SteadyStateUsedDelta); + + if (cur_used_bytes > min_used_targ) { + if (cur_used_bytes <= _prev_collection_pause_used_at_end_bytes) { + } else if (!_g1->mark_in_progress() && !_last_full_young_gc) { + _should_initiate_conc_mark = true; + } + } + + _prev_collection_pause_used_at_end_bytes = cur_used_bytes; + } + + _mmu_tracker->add_pause(end_time_sec - elapsed_ms/1000.0, + end_time_sec, false); + + guarantee(_cur_collection_pause_used_regions_at_start >= + collection_set_size(), + "Negative RS size?"); + + // This assert is exempted when we're doing parallel collection pauses, + // because the fragmentation caused by the parallel GC allocation buffers + // can lead to more memory being used during collection than was used + // before. Best leave this out until the fragmentation problem is fixed. + // Pauses in which evacuation failed can also lead to negative + // collections, since no space is reclaimed from a region containing an + // object whose evacuation failed. + // Further, we're now always doing parallel collection. But I'm still + // leaving this here as a placeholder for a more precise assertion later. + // (DLD, 10/05.) + assert((true || parallel) // Always using GC LABs now. + || _g1->evacuation_failed() + || _cur_collection_pause_used_at_start_bytes >= cur_used_bytes, + "Negative collection"); + + size_t freed_bytes = + _cur_collection_pause_used_at_start_bytes - cur_used_bytes; + size_t surviving_bytes = _collection_set_bytes_used_before - freed_bytes; + double survival_fraction = + (double)surviving_bytes/ + (double)_collection_set_bytes_used_before; + + _n_pauses++; + + if (!abandoned) { + _recent_CH_strong_roots_times_ms->add(_cur_CH_strong_roots_dur_ms); + _recent_G1_strong_roots_times_ms->add(_cur_G1_strong_roots_dur_ms); + _recent_evac_times_ms->add(evac_ms); + _recent_pause_times_ms->add(elapsed_ms); + + _recent_rs_sizes->add(rs_size); + + // We exempt parallel collection from this check because Alloc Buffer + // fragmentation can produce negative collections. Same with evac + // failure. + // Further, we're now always doing parallel collection. But I'm still + // leaving this here as a placeholder for a more precise assertion later. + // (DLD, 10/05. + assert((true || parallel) + || _g1->evacuation_failed() + || surviving_bytes <= _collection_set_bytes_used_before, + "Or else negative collection!"); + _recent_CS_bytes_used_before->add(_collection_set_bytes_used_before); + _recent_CS_bytes_surviving->add(surviving_bytes); + + // this is where we update the allocation rate of the application + double app_time_ms = + (_cur_collection_start_sec * 1000.0 - _prev_collection_pause_end_ms); + if (app_time_ms < MIN_TIMER_GRANULARITY) { + // This usually happens due to the timer not having the required + // granularity. Some Linuxes are the usual culprits. + // We'll just set it to something (arbitrarily) small. + app_time_ms = 1.0; + } + size_t regions_allocated = + (_region_num_young - _prev_region_num_young) + + (_region_num_tenured - _prev_region_num_tenured); + double alloc_rate_ms = (double) regions_allocated / app_time_ms; + _alloc_rate_ms_seq->add(alloc_rate_ms); + _prev_region_num_young = _region_num_young; + _prev_region_num_tenured = _region_num_tenured; + + double interval_ms = + (end_time_sec - _recent_prev_end_times_for_all_gcs_sec->oldest()) * 1000.0; + update_recent_gc_times(end_time_sec, elapsed_ms); + _recent_avg_pause_time_ratio = _recent_gc_times_ms->sum()/interval_ms; + assert(recent_avg_pause_time_ratio() < 1.00, "All GC?"); + } + + if (G1PolicyVerbose > 1) { + gclog_or_tty->print_cr(" Recording collection pause(%d)", _n_pauses); + } + + PauseSummary* summary; + if (!abandoned && !popular) + summary = _non_pop_summary; + else if (!abandoned && popular) + summary = _pop_summary; + else if (abandoned && !popular) + summary = _non_pop_abandoned_summary; + else if (abandoned && popular) + summary = _pop_abandoned_summary; + else + guarantee(false, "should not get here!"); + + double pop_update_rs_time; + double pop_update_rs_processed_buffers; + double pop_scan_rs_time; + double pop_closure_app_time; + double pop_other_time; + + if (popular) { + PopPreambleSummary* preamble_summary = summary->pop_preamble_summary(); + guarantee(preamble_summary != NULL, "should not be null!"); + + pop_update_rs_time = avg_value(_pop_par_last_update_rs_times_ms); + pop_update_rs_processed_buffers = + sum_of_values(_pop_par_last_update_rs_processed_buffers); + pop_scan_rs_time = avg_value(_pop_par_last_scan_rs_times_ms); + pop_closure_app_time = avg_value(_pop_par_last_closure_app_times_ms); + pop_other_time = _cur_popular_preamble_time_ms - + (pop_update_rs_time + pop_scan_rs_time + pop_closure_app_time + + _cur_popular_evac_time_ms); + + preamble_summary->record_pop_preamble_time_ms(_cur_popular_preamble_time_ms); + preamble_summary->record_pop_update_rs_time_ms(pop_update_rs_time); + preamble_summary->record_pop_scan_rs_time_ms(pop_scan_rs_time); + preamble_summary->record_pop_closure_app_time_ms(pop_closure_app_time); + preamble_summary->record_pop_evacuation_time_ms(_cur_popular_evac_time_ms); + preamble_summary->record_pop_other_time_ms(pop_other_time); + } + + double ext_root_scan_time = avg_value(_par_last_ext_root_scan_times_ms); + double mark_stack_scan_time = avg_value(_par_last_mark_stack_scan_times_ms); + double scan_only_time = avg_value(_par_last_scan_only_times_ms); + double scan_only_regions_scanned = + sum_of_values(_par_last_scan_only_regions_scanned); + double update_rs_time = avg_value(_par_last_update_rs_times_ms); + double update_rs_processed_buffers = + sum_of_values(_par_last_update_rs_processed_buffers); + double scan_rs_time = avg_value(_par_last_scan_rs_times_ms); + double obj_copy_time = avg_value(_par_last_obj_copy_times_ms); + double termination_time = avg_value(_par_last_termination_times_ms); + + double parallel_other_time; + if (!abandoned) { + MainBodySummary* body_summary = summary->main_body_summary(); + guarantee(body_summary != NULL, "should not be null!"); + + if (_satb_drain_time_set) + body_summary->record_satb_drain_time_ms(_cur_satb_drain_time_ms); + else + body_summary->record_satb_drain_time_ms(0.0); + body_summary->record_ext_root_scan_time_ms(ext_root_scan_time); + body_summary->record_mark_stack_scan_time_ms(mark_stack_scan_time); + body_summary->record_scan_only_time_ms(scan_only_time); + body_summary->record_update_rs_time_ms(update_rs_time); + body_summary->record_scan_rs_time_ms(scan_rs_time); + body_summary->record_obj_copy_time_ms(obj_copy_time); + if (parallel) { + body_summary->record_parallel_time_ms(_cur_collection_par_time_ms); + body_summary->record_clear_ct_time_ms(_cur_clear_ct_time_ms); + body_summary->record_termination_time_ms(termination_time); + parallel_other_time = _cur_collection_par_time_ms - + (update_rs_time + ext_root_scan_time + mark_stack_scan_time + + scan_only_time + scan_rs_time + obj_copy_time + termination_time); + body_summary->record_parallel_other_time_ms(parallel_other_time); + } + body_summary->record_mark_closure_time_ms(_mark_closure_time_ms); + } + + if (G1PolicyVerbose > 1) { + gclog_or_tty->print_cr(" ET: %10.6f ms (avg: %10.6f ms)\n" + " CH Strong: %10.6f ms (avg: %10.6f ms)\n" + " G1 Strong: %10.6f ms (avg: %10.6f ms)\n" + " Evac: %10.6f ms (avg: %10.6f ms)\n" + " ET-RS: %10.6f ms (avg: %10.6f ms)\n" + " |RS|: " SIZE_FORMAT, + elapsed_ms, recent_avg_time_for_pauses_ms(), + _cur_CH_strong_roots_dur_ms, recent_avg_time_for_CH_strong_ms(), + _cur_G1_strong_roots_dur_ms, recent_avg_time_for_G1_strong_ms(), + evac_ms, recent_avg_time_for_evac_ms(), + scan_rs_time, + recent_avg_time_for_pauses_ms() - + recent_avg_time_for_G1_strong_ms(), + rs_size); + + gclog_or_tty->print_cr(" Used at start: " SIZE_FORMAT"K" + " At end " SIZE_FORMAT "K\n" + " garbage : " SIZE_FORMAT "K" + " of " SIZE_FORMAT "K\n" + " survival : %6.2f%% (%6.2f%% avg)", + _cur_collection_pause_used_at_start_bytes/K, + _g1->used()/K, freed_bytes/K, + _collection_set_bytes_used_before/K, + survival_fraction*100.0, + recent_avg_survival_fraction()*100.0); + gclog_or_tty->print_cr(" Recent %% gc pause time: %6.2f", + recent_avg_pause_time_ratio() * 100.0); + } + + double other_time_ms = elapsed_ms; + if (popular) + other_time_ms -= _cur_popular_preamble_time_ms; + + if (!abandoned) { + if (_satb_drain_time_set) + other_time_ms -= _cur_satb_drain_time_ms; + + if (parallel) + other_time_ms -= _cur_collection_par_time_ms + _cur_clear_ct_time_ms; + else + other_time_ms -= + update_rs_time + + ext_root_scan_time + mark_stack_scan_time + scan_only_time + + scan_rs_time + obj_copy_time; + } + + if (PrintGCDetails) { + gclog_or_tty->print_cr("%s%s, %1.8lf secs]", + (popular && !abandoned) ? " (popular)" : + (!popular && abandoned) ? " (abandoned)" : + (popular && abandoned) ? " (popular/abandoned)" : "", + (last_pause_included_initial_mark) ? " (initial-mark)" : "", + elapsed_ms / 1000.0); + + if (!abandoned) { + if (_satb_drain_time_set) + print_stats(1, "SATB Drain Time", _cur_satb_drain_time_ms); + if (_last_satb_drain_processed_buffers >= 0) + print_stats(2, "Processed Buffers", _last_satb_drain_processed_buffers); + } + if (popular) + print_stats(1, "Popularity Preamble", _cur_popular_preamble_time_ms); + if (parallel) { + if (popular) { + print_par_stats(2, "Update RS (Start)", _pop_par_last_update_rs_start_times_ms, false); + print_par_stats(2, "Update RS", _pop_par_last_update_rs_times_ms); + if (G1RSBarrierUseQueue) + print_par_buffers(3, "Processed Buffers", + _pop_par_last_update_rs_processed_buffers, true); + print_par_stats(2, "Scan RS", _pop_par_last_scan_rs_times_ms); + print_par_stats(2, "Closure app", _pop_par_last_closure_app_times_ms); + print_stats(2, "Evacuation", _cur_popular_evac_time_ms); + print_stats(2, "Other", pop_other_time); + } + if (!abandoned) { + print_stats(1, "Parallel Time", _cur_collection_par_time_ms); + if (!popular) { + print_par_stats(2, "Update RS (Start)", _par_last_update_rs_start_times_ms, false); + print_par_stats(2, "Update RS", _par_last_update_rs_times_ms); + if (G1RSBarrierUseQueue) + print_par_buffers(3, "Processed Buffers", + _par_last_update_rs_processed_buffers, true); + } + print_par_stats(2, "Ext Root Scanning", _par_last_ext_root_scan_times_ms); + print_par_stats(2, "Mark Stack Scanning", _par_last_mark_stack_scan_times_ms); + print_par_stats(2, "Scan-Only Scanning", _par_last_scan_only_times_ms); + print_par_buffers(3, "Scan-Only Regions", + _par_last_scan_only_regions_scanned, true); + print_par_stats(2, "Scan RS", _par_last_scan_rs_times_ms); + print_par_stats(2, "Object Copy", _par_last_obj_copy_times_ms); + print_par_stats(2, "Termination", _par_last_termination_times_ms); + print_stats(2, "Other", parallel_other_time); + print_stats(1, "Clear CT", _cur_clear_ct_time_ms); + } + } else { + if (popular) { + print_stats(2, "Update RS", pop_update_rs_time); + if (G1RSBarrierUseQueue) + print_stats(3, "Processed Buffers", + (int)pop_update_rs_processed_buffers); + print_stats(2, "Scan RS", pop_scan_rs_time); + print_stats(2, "Closure App", pop_closure_app_time); + print_stats(2, "Evacuation", _cur_popular_evac_time_ms); + print_stats(2, "Other", pop_other_time); + } + if (!abandoned) { + if (!popular) { + print_stats(1, "Update RS", update_rs_time); + if (G1RSBarrierUseQueue) + print_stats(2, "Processed Buffers", + (int)update_rs_processed_buffers); + } + print_stats(1, "Ext Root Scanning", ext_root_scan_time); + print_stats(1, "Mark Stack Scanning", mark_stack_scan_time); + print_stats(1, "Scan-Only Scanning", scan_only_time); + print_stats(1, "Scan RS", scan_rs_time); + print_stats(1, "Object Copying", obj_copy_time); + } + } + print_stats(1, "Other", other_time_ms); + for (int i = 0; i < _aux_num; ++i) { + if (_cur_aux_times_set[i]) { + char buffer[96]; + sprintf(buffer, "Aux%d", i); + print_stats(1, buffer, _cur_aux_times_ms[i]); + } + } + } + if (PrintGCDetails) + gclog_or_tty->print(" ["); + if (PrintGC || PrintGCDetails) + _g1->print_size_transition(gclog_or_tty, + _cur_collection_pause_used_at_start_bytes, + _g1->used(), _g1->capacity()); + if (PrintGCDetails) + gclog_or_tty->print_cr("]"); + + _all_pause_times_ms->add(elapsed_ms); + summary->record_total_time_ms(elapsed_ms); + summary->record_other_time_ms(other_time_ms); + for (int i = 0; i < _aux_num; ++i) + if (_cur_aux_times_set[i]) + _all_aux_times_ms[i].add(_cur_aux_times_ms[i]); + + // Reset marks-between-pauses counter. + _n_marks_since_last_pause = 0; + + // Update the efficiency-since-mark vars. + double proc_ms = elapsed_ms * (double) _parallel_gc_threads; + if (elapsed_ms < MIN_TIMER_GRANULARITY) { + // This usually happens due to the timer not having the required + // granularity. Some Linuxes are the usual culprits. + // We'll just set it to something (arbitrarily) small. + proc_ms = 1.0; + } + double cur_efficiency = (double) freed_bytes / proc_ms; + + bool new_in_marking_window = _in_marking_window; + bool new_in_marking_window_im = false; + if (_should_initiate_conc_mark) { + new_in_marking_window = true; + new_in_marking_window_im = true; + } + + if (in_young_gc_mode()) { + if (_last_full_young_gc) { + set_full_young_gcs(false); + _last_full_young_gc = false; + } + + if ( !_last_young_gc_full ) { + if ( _should_revert_to_full_young_gcs || + _known_garbage_ratio < 0.05 || + (adaptive_young_list_length() && + (get_gc_eff_factor() * cur_efficiency < predict_young_gc_eff())) ) { + set_full_young_gcs(true); + } + } + _should_revert_to_full_young_gcs = false; + + if (_last_young_gc_full && !_during_marking) + _young_gc_eff_seq->add(cur_efficiency); + } + + _short_lived_surv_rate_group->start_adding_regions(); + // do that for any other surv rate groupsx + + // + + if (!popular && !abandoned) { + double pause_time_ms = elapsed_ms; + + size_t diff = 0; + if (_max_pending_cards >= _pending_cards) + diff = _max_pending_cards - _pending_cards; + _pending_card_diff_seq->add((double) diff); + + double cost_per_card_ms = 0.0; + if (_pending_cards > 0) { + cost_per_card_ms = update_rs_time / (double) _pending_cards; + _cost_per_card_ms_seq->add(cost_per_card_ms); + } + + double cost_per_scan_only_region_ms = 0.0; + if (scan_only_regions_scanned > 0.0) { + cost_per_scan_only_region_ms = + scan_only_time / scan_only_regions_scanned; + if (_in_marking_window_im) + _cost_per_scan_only_region_ms_during_cm_seq->add(cost_per_scan_only_region_ms); + else + _cost_per_scan_only_region_ms_seq->add(cost_per_scan_only_region_ms); + } + + size_t cards_scanned = _g1->cards_scanned(); + + double cost_per_entry_ms = 0.0; + if (cards_scanned > 10) { + cost_per_entry_ms = scan_rs_time / (double) cards_scanned; + if (_last_young_gc_full) + _cost_per_entry_ms_seq->add(cost_per_entry_ms); + else + _partially_young_cost_per_entry_ms_seq->add(cost_per_entry_ms); + } + + if (_max_rs_lengths > 0) { + double cards_per_entry_ratio = + (double) cards_scanned / (double) _max_rs_lengths; + if (_last_young_gc_full) + _fully_young_cards_per_entry_ratio_seq->add(cards_per_entry_ratio); + else + _partially_young_cards_per_entry_ratio_seq->add(cards_per_entry_ratio); + } + + size_t rs_length_diff = _max_rs_lengths - _recorded_rs_lengths; + if (rs_length_diff >= 0) + _rs_length_diff_seq->add((double) rs_length_diff); + + size_t copied_bytes = surviving_bytes; + double cost_per_byte_ms = 0.0; + if (copied_bytes > 0) { + cost_per_byte_ms = obj_copy_time / (double) copied_bytes; + if (_in_marking_window) + _cost_per_byte_ms_during_cm_seq->add(cost_per_byte_ms); + else + _cost_per_byte_ms_seq->add(cost_per_byte_ms); + } + + double all_other_time_ms = pause_time_ms - + (update_rs_time + scan_only_time + scan_rs_time + obj_copy_time + + _mark_closure_time_ms + termination_time); + + double young_other_time_ms = 0.0; + if (_recorded_young_regions > 0) { + young_other_time_ms = + _recorded_young_cset_choice_time_ms + + _recorded_young_free_cset_time_ms; + _young_other_cost_per_region_ms_seq->add(young_other_time_ms / + (double) _recorded_young_regions); + } + double non_young_other_time_ms = 0.0; + if (_recorded_non_young_regions > 0) { + non_young_other_time_ms = + _recorded_non_young_cset_choice_time_ms + + _recorded_non_young_free_cset_time_ms; + + _non_young_other_cost_per_region_ms_seq->add(non_young_other_time_ms / + (double) _recorded_non_young_regions); + } + + double constant_other_time_ms = all_other_time_ms - + (young_other_time_ms + non_young_other_time_ms); + _constant_other_time_ms_seq->add(constant_other_time_ms); + + double survival_ratio = 0.0; + if (_bytes_in_collection_set_before_gc > 0) { + survival_ratio = (double) bytes_in_to_space_during_gc() / + (double) _bytes_in_collection_set_before_gc; + } + + _pending_cards_seq->add((double) _pending_cards); + _scanned_cards_seq->add((double) cards_scanned); + _rs_lengths_seq->add((double) _max_rs_lengths); + + double expensive_region_limit_ms = + (double) G1MaxPauseTimeMS - predict_constant_other_time_ms(); + if (expensive_region_limit_ms < 0.0) { + // this means that the other time was predicted to be longer than + // than the max pause time + expensive_region_limit_ms = (double) G1MaxPauseTimeMS; + } + _expensive_region_limit_ms = expensive_region_limit_ms; + + if (PREDICTIONS_VERBOSE) { + gclog_or_tty->print_cr(""); + gclog_or_tty->print_cr("PREDICTIONS %1.4lf %d " + "REGIONS %d %d %d %d " + "PENDING_CARDS %d %d " + "CARDS_SCANNED %d %d " + "RS_LENGTHS %d %d " + "SCAN_ONLY_SCAN %1.6lf %1.6lf " + "RS_UPDATE %1.6lf %1.6lf RS_SCAN %1.6lf %1.6lf " + "SURVIVAL_RATIO %1.6lf %1.6lf " + "OBJECT_COPY %1.6lf %1.6lf OTHER_CONSTANT %1.6lf %1.6lf " + "OTHER_YOUNG %1.6lf %1.6lf " + "OTHER_NON_YOUNG %1.6lf %1.6lf " + "VTIME_DIFF %1.6lf TERMINATION %1.6lf " + "ELAPSED %1.6lf %1.6lf ", + _cur_collection_start_sec, + (!_last_young_gc_full) ? 2 : + (last_pause_included_initial_mark) ? 1 : 0, + _recorded_region_num, + _recorded_young_regions, + _recorded_scan_only_regions, + _recorded_non_young_regions, + _predicted_pending_cards, _pending_cards, + _predicted_cards_scanned, cards_scanned, + _predicted_rs_lengths, _max_rs_lengths, + _predicted_scan_only_scan_time_ms, scan_only_time, + _predicted_rs_update_time_ms, update_rs_time, + _predicted_rs_scan_time_ms, scan_rs_time, + _predicted_survival_ratio, survival_ratio, + _predicted_object_copy_time_ms, obj_copy_time, + _predicted_constant_other_time_ms, constant_other_time_ms, + _predicted_young_other_time_ms, young_other_time_ms, + _predicted_non_young_other_time_ms, + non_young_other_time_ms, + _vtime_diff_ms, termination_time, + _predicted_pause_time_ms, elapsed_ms); + } + + if (G1PolicyVerbose > 0) { + gclog_or_tty->print_cr("Pause Time, predicted: %1.4lfms (predicted %s), actual: %1.4lfms", + _predicted_pause_time_ms, + (_within_target) ? "within" : "outside", + elapsed_ms); + } + + } + + _in_marking_window = new_in_marking_window; + _in_marking_window_im = new_in_marking_window_im; + _free_regions_at_end_of_collection = _g1->free_regions(); + _scan_only_regions_at_end_of_collection = _g1->young_list_length(); + calculate_young_list_min_length(); + calculate_young_list_target_config(); + + // + + _target_pause_time_ms = -1.0; + + // TODO: calculate tenuring threshold + _tenuring_threshold = MaxTenuringThreshold; +} + +// + +double +G1CollectorPolicy:: +predict_young_collection_elapsed_time_ms(size_t adjustment) { + guarantee( adjustment == 0 || adjustment == 1, "invariant" ); + + G1CollectedHeap* g1h = G1CollectedHeap::heap(); + size_t young_num = g1h->young_list_length(); + if (young_num == 0) + return 0.0; + + young_num += adjustment; + size_t pending_cards = predict_pending_cards(); + size_t rs_lengths = g1h->young_list_sampled_rs_lengths() + + predict_rs_length_diff(); + size_t card_num; + if (full_young_gcs()) + card_num = predict_young_card_num(rs_lengths); + else + card_num = predict_non_young_card_num(rs_lengths); + size_t young_byte_size = young_num * HeapRegion::GrainBytes; + double accum_yg_surv_rate = + _short_lived_surv_rate_group->accum_surv_rate(adjustment); + + size_t bytes_to_copy = + (size_t) (accum_yg_surv_rate * (double) HeapRegion::GrainBytes); + + return + predict_rs_update_time_ms(pending_cards) + + predict_rs_scan_time_ms(card_num) + + predict_object_copy_time_ms(bytes_to_copy) + + predict_young_other_time_ms(young_num) + + predict_constant_other_time_ms(); +} + +double +G1CollectorPolicy::predict_base_elapsed_time_ms(size_t pending_cards) { + size_t rs_length = predict_rs_length_diff(); + size_t card_num; + if (full_young_gcs()) + card_num = predict_young_card_num(rs_length); + else + card_num = predict_non_young_card_num(rs_length); + return predict_base_elapsed_time_ms(pending_cards, card_num); +} + +double +G1CollectorPolicy::predict_base_elapsed_time_ms(size_t pending_cards, + size_t scanned_cards) { + return + predict_rs_update_time_ms(pending_cards) + + predict_rs_scan_time_ms(scanned_cards) + + predict_constant_other_time_ms(); +} + +double +G1CollectorPolicy::predict_region_elapsed_time_ms(HeapRegion* hr, + bool young) { + size_t rs_length = hr->rem_set()->occupied(); + size_t card_num; + if (full_young_gcs()) + card_num = predict_young_card_num(rs_length); + else + card_num = predict_non_young_card_num(rs_length); + size_t bytes_to_copy = predict_bytes_to_copy(hr); + + double region_elapsed_time_ms = + predict_rs_scan_time_ms(card_num) + + predict_object_copy_time_ms(bytes_to_copy); + + if (young) + region_elapsed_time_ms += predict_young_other_time_ms(1); + else + region_elapsed_time_ms += predict_non_young_other_time_ms(1); + + return region_elapsed_time_ms; +} + +size_t +G1CollectorPolicy::predict_bytes_to_copy(HeapRegion* hr) { + size_t bytes_to_copy; + if (hr->is_marked()) + bytes_to_copy = hr->max_live_bytes(); + else { + guarantee( hr->is_young() && hr->age_in_surv_rate_group() != -1, + "invariant" ); + int age = hr->age_in_surv_rate_group(); + double yg_surv_rate = predict_yg_surv_rate(age); + bytes_to_copy = (size_t) ((double) hr->used() * yg_surv_rate); + } + + return bytes_to_copy; +} + +void +G1CollectorPolicy::start_recording_regions() { + _recorded_rs_lengths = 0; + _recorded_scan_only_regions = 0; + _recorded_young_regions = 0; + _recorded_non_young_regions = 0; + +#if PREDICTIONS_VERBOSE + _predicted_rs_lengths = 0; + _predicted_cards_scanned = 0; + + _recorded_marked_bytes = 0; + _recorded_young_bytes = 0; + _predicted_bytes_to_copy = 0; +#endif // PREDICTIONS_VERBOSE +} + +void +G1CollectorPolicy::record_cset_region(HeapRegion* hr, bool young) { + if (young) { + ++_recorded_young_regions; + } else { + ++_recorded_non_young_regions; + } +#if PREDICTIONS_VERBOSE + if (young) { + _recorded_young_bytes += hr->asSpace()->used(); + } else { + _recorded_marked_bytes += hr->max_live_bytes(); + } + _predicted_bytes_to_copy += predict_bytes_to_copy(hr); +#endif // PREDICTIONS_VERBOSE + + size_t rs_length = hr->rem_set()->occupied(); + _recorded_rs_lengths += rs_length; +} + +void +G1CollectorPolicy::record_scan_only_regions(size_t scan_only_length) { + _recorded_scan_only_regions = scan_only_length; +} + +void +G1CollectorPolicy::end_recording_regions() { +#if PREDICTIONS_VERBOSE + _predicted_pending_cards = predict_pending_cards(); + _predicted_rs_lengths = _recorded_rs_lengths + predict_rs_length_diff(); + if (full_young_gcs()) + _predicted_cards_scanned += predict_young_card_num(_predicted_rs_lengths); + else + _predicted_cards_scanned += + predict_non_young_card_num(_predicted_rs_lengths); + _recorded_region_num = _recorded_young_regions + _recorded_non_young_regions; + + _predicted_young_survival_ratio = 0.0; + for (int i = 0; i < _recorded_young_regions; ++i) + _predicted_young_survival_ratio += predict_yg_surv_rate(i); + _predicted_young_survival_ratio /= (double) _recorded_young_regions; + + _predicted_scan_only_scan_time_ms = + predict_scan_only_time_ms(_recorded_scan_only_regions); + _predicted_rs_update_time_ms = + predict_rs_update_time_ms(_g1->pending_card_num()); + _predicted_rs_scan_time_ms = + predict_rs_scan_time_ms(_predicted_cards_scanned); + _predicted_object_copy_time_ms = + predict_object_copy_time_ms(_predicted_bytes_to_copy); + _predicted_constant_other_time_ms = + predict_constant_other_time_ms(); + _predicted_young_other_time_ms = + predict_young_other_time_ms(_recorded_young_regions); + _predicted_non_young_other_time_ms = + predict_non_young_other_time_ms(_recorded_non_young_regions); + + _predicted_pause_time_ms = + _predicted_scan_only_scan_time_ms + + _predicted_rs_update_time_ms + + _predicted_rs_scan_time_ms + + _predicted_object_copy_time_ms + + _predicted_constant_other_time_ms + + _predicted_young_other_time_ms + + _predicted_non_young_other_time_ms; +#endif // PREDICTIONS_VERBOSE +} + +void G1CollectorPolicy::check_if_region_is_too_expensive(double + predicted_time_ms) { + // I don't think we need to do this when in young GC mode since + // marking will be initiated next time we hit the soft limit anyway... + if (predicted_time_ms > _expensive_region_limit_ms) { + if (!in_young_gc_mode()) { + set_full_young_gcs(true); + _should_initiate_conc_mark = true; + } else + // no point in doing another partial one + _should_revert_to_full_young_gcs = true; + } +} + +// + + +void G1CollectorPolicy::update_recent_gc_times(double end_time_sec, + double elapsed_ms) { + _recent_gc_times_ms->add(elapsed_ms); + _recent_prev_end_times_for_all_gcs_sec->add(end_time_sec); + _prev_collection_pause_end_ms = end_time_sec * 1000.0; +} + +double G1CollectorPolicy::recent_avg_time_for_pauses_ms() { + if (_recent_pause_times_ms->num() == 0) return (double) G1MaxPauseTimeMS; + else return _recent_pause_times_ms->avg(); +} + +double G1CollectorPolicy::recent_avg_time_for_CH_strong_ms() { + if (_recent_CH_strong_roots_times_ms->num() == 0) + return (double)G1MaxPauseTimeMS/3.0; + else return _recent_CH_strong_roots_times_ms->avg(); +} + +double G1CollectorPolicy::recent_avg_time_for_G1_strong_ms() { + if (_recent_G1_strong_roots_times_ms->num() == 0) + return (double)G1MaxPauseTimeMS/3.0; + else return _recent_G1_strong_roots_times_ms->avg(); +} + +double G1CollectorPolicy::recent_avg_time_for_evac_ms() { + if (_recent_evac_times_ms->num() == 0) return (double)G1MaxPauseTimeMS/3.0; + else return _recent_evac_times_ms->avg(); +} + +int G1CollectorPolicy::number_of_recent_gcs() { + assert(_recent_CH_strong_roots_times_ms->num() == + _recent_G1_strong_roots_times_ms->num(), "Sequence out of sync"); + assert(_recent_G1_strong_roots_times_ms->num() == + _recent_evac_times_ms->num(), "Sequence out of sync"); + assert(_recent_evac_times_ms->num() == + _recent_pause_times_ms->num(), "Sequence out of sync"); + assert(_recent_pause_times_ms->num() == + _recent_CS_bytes_used_before->num(), "Sequence out of sync"); + assert(_recent_CS_bytes_used_before->num() == + _recent_CS_bytes_surviving->num(), "Sequence out of sync"); + return _recent_pause_times_ms->num(); +} + +double G1CollectorPolicy::recent_avg_survival_fraction() { + return recent_avg_survival_fraction_work(_recent_CS_bytes_surviving, + _recent_CS_bytes_used_before); +} + +double G1CollectorPolicy::last_survival_fraction() { + return last_survival_fraction_work(_recent_CS_bytes_surviving, + _recent_CS_bytes_used_before); +} + +double +G1CollectorPolicy::recent_avg_survival_fraction_work(TruncatedSeq* surviving, + TruncatedSeq* before) { + assert(surviving->num() == before->num(), "Sequence out of sync"); + if (before->sum() > 0.0) { + double recent_survival_rate = surviving->sum() / before->sum(); + // We exempt parallel collection from this check because Alloc Buffer + // fragmentation can produce negative collections. + // Further, we're now always doing parallel collection. But I'm still + // leaving this here as a placeholder for a more precise assertion later. + // (DLD, 10/05.) + assert((true || ParallelGCThreads > 0) || + _g1->evacuation_failed() || + recent_survival_rate <= 1.0, "Or bad frac"); + return recent_survival_rate; + } else { + return 1.0; // Be conservative. + } +} + +double +G1CollectorPolicy::last_survival_fraction_work(TruncatedSeq* surviving, + TruncatedSeq* before) { + assert(surviving->num() == before->num(), "Sequence out of sync"); + if (surviving->num() > 0 && before->last() > 0.0) { + double last_survival_rate = surviving->last() / before->last(); + // We exempt parallel collection from this check because Alloc Buffer + // fragmentation can produce negative collections. + // Further, we're now always doing parallel collection. But I'm still + // leaving this here as a placeholder for a more precise assertion later. + // (DLD, 10/05.) + assert((true || ParallelGCThreads > 0) || + last_survival_rate <= 1.0, "Or bad frac"); + return last_survival_rate; + } else { + return 1.0; + } +} + +static const int survival_min_obs = 5; +static double survival_min_obs_limits[] = { 0.9, 0.7, 0.5, 0.3, 0.1 }; +static const double min_survival_rate = 0.1; + +double +G1CollectorPolicy::conservative_avg_survival_fraction_work(double avg, + double latest) { + double res = avg; + if (number_of_recent_gcs() < survival_min_obs) { + res = MAX2(res, survival_min_obs_limits[number_of_recent_gcs()]); + } + res = MAX2(res, latest); + res = MAX2(res, min_survival_rate); + // In the parallel case, LAB fragmentation can produce "negative + // collections"; so can evac failure. Cap at 1.0 + res = MIN2(res, 1.0); + return res; +} + +size_t G1CollectorPolicy::expansion_amount() { + if ((int)(recent_avg_pause_time_ratio() * 100.0) > G1GCPct) { + // We will double the existing space, or take G1ExpandByPctOfAvail % of + // the available expansion space, whichever is smaller, bounded below + // by a minimum expansion (unless that's all that's left.) + const size_t min_expand_bytes = 1*M; + size_t reserved_bytes = _g1->g1_reserved_obj_bytes(); + size_t committed_bytes = _g1->capacity(); + size_t uncommitted_bytes = reserved_bytes - committed_bytes; + size_t expand_bytes; + size_t expand_bytes_via_pct = + uncommitted_bytes * G1ExpandByPctOfAvail / 100; + expand_bytes = MIN2(expand_bytes_via_pct, committed_bytes); + expand_bytes = MAX2(expand_bytes, min_expand_bytes); + expand_bytes = MIN2(expand_bytes, uncommitted_bytes); + if (G1PolicyVerbose > 1) { + gclog_or_tty->print("Decided to expand: ratio = %5.2f, " + "committed = %d%s, uncommited = %d%s, via pct = %d%s.\n" + " Answer = %d.\n", + recent_avg_pause_time_ratio(), + byte_size_in_proper_unit(committed_bytes), + proper_unit_for_byte_size(committed_bytes), + byte_size_in_proper_unit(uncommitted_bytes), + proper_unit_for_byte_size(uncommitted_bytes), + byte_size_in_proper_unit(expand_bytes_via_pct), + proper_unit_for_byte_size(expand_bytes_via_pct), + byte_size_in_proper_unit(expand_bytes), + proper_unit_for_byte_size(expand_bytes)); + } + return expand_bytes; + } else { + return 0; + } +} + +void G1CollectorPolicy::note_start_of_mark_thread() { + _mark_thread_startup_sec = os::elapsedTime(); +} + +class CountCSClosure: public HeapRegionClosure { + G1CollectorPolicy* _g1_policy; +public: + CountCSClosure(G1CollectorPolicy* g1_policy) : + _g1_policy(g1_policy) {} + bool doHeapRegion(HeapRegion* r) { + _g1_policy->_bytes_in_collection_set_before_gc += r->used(); + return false; + } +}; + +void G1CollectorPolicy::count_CS_bytes_used() { + CountCSClosure cs_closure(this); + _g1->collection_set_iterate(&cs_closure); +} + +static void print_indent(int level) { + for (int j = 0; j < level+1; ++j) + gclog_or_tty->print(" "); +} + +void G1CollectorPolicy::print_summary (int level, + const char* str, + NumberSeq* seq) const { + double sum = seq->sum(); + print_indent(level); + gclog_or_tty->print_cr("%-24s = %8.2lf s (avg = %8.2lf ms)", + str, sum / 1000.0, seq->avg()); +} + +void G1CollectorPolicy::print_summary_sd (int level, + const char* str, + NumberSeq* seq) const { + print_summary(level, str, seq); + print_indent(level + 5); + gclog_or_tty->print_cr("(num = %5d, std dev = %8.2lf ms, max = %8.2lf ms)", + seq->num(), seq->sd(), seq->maximum()); +} + +void G1CollectorPolicy::check_other_times(int level, + NumberSeq* other_times_ms, + NumberSeq* calc_other_times_ms) const { + bool should_print = false; + + double max_sum = MAX2(fabs(other_times_ms->sum()), + fabs(calc_other_times_ms->sum())); + double min_sum = MIN2(fabs(other_times_ms->sum()), + fabs(calc_other_times_ms->sum())); + double sum_ratio = max_sum / min_sum; + if (sum_ratio > 1.1) { + should_print = true; + print_indent(level + 1); + gclog_or_tty->print_cr("## CALCULATED OTHER SUM DOESN'T MATCH RECORDED ###"); + } + + double max_avg = MAX2(fabs(other_times_ms->avg()), + fabs(calc_other_times_ms->avg())); + double min_avg = MIN2(fabs(other_times_ms->avg()), + fabs(calc_other_times_ms->avg())); + double avg_ratio = max_avg / min_avg; + if (avg_ratio > 1.1) { + should_print = true; + print_indent(level + 1); + gclog_or_tty->print_cr("## CALCULATED OTHER AVG DOESN'T MATCH RECORDED ###"); + } + + if (other_times_ms->sum() < -0.01) { + print_indent(level + 1); + gclog_or_tty->print_cr("## RECORDED OTHER SUM IS NEGATIVE ###"); + } + + if (other_times_ms->avg() < -0.01) { + print_indent(level + 1); + gclog_or_tty->print_cr("## RECORDED OTHER AVG IS NEGATIVE ###"); + } + + if (calc_other_times_ms->sum() < -0.01) { + should_print = true; + print_indent(level + 1); + gclog_or_tty->print_cr("## CALCULATED OTHER SUM IS NEGATIVE ###"); + } + + if (calc_other_times_ms->avg() < -0.01) { + should_print = true; + print_indent(level + 1); + gclog_or_tty->print_cr("## CALCULATED OTHER AVG IS NEGATIVE ###"); + } + + if (should_print) + print_summary(level, "Other(Calc)", calc_other_times_ms); +} + +void G1CollectorPolicy::print_summary(PauseSummary* summary) const { + bool parallel = ParallelGCThreads > 0; + MainBodySummary* body_summary = summary->main_body_summary(); + PopPreambleSummary* preamble_summary = summary->pop_preamble_summary(); + + if (summary->get_total_seq()->num() > 0) { + print_summary_sd(0, + (preamble_summary == NULL) ? "Non-Popular Pauses" : + "Popular Pauses", + summary->get_total_seq()); + if (preamble_summary != NULL) { + print_summary(1, "Popularity Preamble", + preamble_summary->get_pop_preamble_seq()); + print_summary(2, "Update RS", preamble_summary->get_pop_update_rs_seq()); + print_summary(2, "Scan RS", preamble_summary->get_pop_scan_rs_seq()); + print_summary(2, "Closure App", + preamble_summary->get_pop_closure_app_seq()); + print_summary(2, "Evacuation", + preamble_summary->get_pop_evacuation_seq()); + print_summary(2, "Other", preamble_summary->get_pop_other_seq()); + { + NumberSeq* other_parts[] = { + preamble_summary->get_pop_update_rs_seq(), + preamble_summary->get_pop_scan_rs_seq(), + preamble_summary->get_pop_closure_app_seq(), + preamble_summary->get_pop_evacuation_seq() + }; + NumberSeq calc_other_times_ms(preamble_summary->get_pop_preamble_seq(), + 4, other_parts); + check_other_times(2, preamble_summary->get_pop_other_seq(), + &calc_other_times_ms); + } + } + if (body_summary != NULL) { + print_summary(1, "SATB Drain", body_summary->get_satb_drain_seq()); + if (parallel) { + print_summary(1, "Parallel Time", body_summary->get_parallel_seq()); + print_summary(2, "Update RS", body_summary->get_update_rs_seq()); + print_summary(2, "Ext Root Scanning", + body_summary->get_ext_root_scan_seq()); + print_summary(2, "Mark Stack Scanning", + body_summary->get_mark_stack_scan_seq()); + print_summary(2, "Scan-Only Scanning", + body_summary->get_scan_only_seq()); + print_summary(2, "Scan RS", body_summary->get_scan_rs_seq()); + print_summary(2, "Object Copy", body_summary->get_obj_copy_seq()); + print_summary(2, "Termination", body_summary->get_termination_seq()); + print_summary(2, "Other", body_summary->get_parallel_other_seq()); + { + NumberSeq* other_parts[] = { + body_summary->get_update_rs_seq(), + body_summary->get_ext_root_scan_seq(), + body_summary->get_mark_stack_scan_seq(), + body_summary->get_scan_only_seq(), + body_summary->get_scan_rs_seq(), + body_summary->get_obj_copy_seq(), + body_summary->get_termination_seq() + }; + NumberSeq calc_other_times_ms(body_summary->get_parallel_seq(), + 7, other_parts); + check_other_times(2, body_summary->get_parallel_other_seq(), + &calc_other_times_ms); + } + print_summary(1, "Mark Closure", body_summary->get_mark_closure_seq()); + print_summary(1, "Clear CT", body_summary->get_clear_ct_seq()); + } else { + print_summary(1, "Update RS", body_summary->get_update_rs_seq()); + print_summary(1, "Ext Root Scanning", + body_summary->get_ext_root_scan_seq()); + print_summary(1, "Mark Stack Scanning", + body_summary->get_mark_stack_scan_seq()); + print_summary(1, "Scan-Only Scanning", + body_summary->get_scan_only_seq()); + print_summary(1, "Scan RS", body_summary->get_scan_rs_seq()); + print_summary(1, "Object Copy", body_summary->get_obj_copy_seq()); + } + } + print_summary(1, "Other", summary->get_other_seq()); + { + NumberSeq calc_other_times_ms; + if (body_summary != NULL) { + // not abandoned + if (parallel) { + // parallel + NumberSeq* other_parts[] = { + body_summary->get_satb_drain_seq(), + (preamble_summary == NULL) ? NULL : + preamble_summary->get_pop_preamble_seq(), + body_summary->get_parallel_seq(), + body_summary->get_clear_ct_seq() + }; + calc_other_times_ms = NumberSeq (summary->get_total_seq(), + 4, other_parts); + } else { + // serial + NumberSeq* other_parts[] = { + body_summary->get_satb_drain_seq(), + (preamble_summary == NULL) ? NULL : + preamble_summary->get_pop_preamble_seq(), + body_summary->get_update_rs_seq(), + body_summary->get_ext_root_scan_seq(), + body_summary->get_mark_stack_scan_seq(), + body_summary->get_scan_only_seq(), + body_summary->get_scan_rs_seq(), + body_summary->get_obj_copy_seq() + }; + calc_other_times_ms = NumberSeq(summary->get_total_seq(), + 8, other_parts); + } + } else { + // abandoned + NumberSeq* other_parts[] = { + (preamble_summary == NULL) ? NULL : + preamble_summary->get_pop_preamble_seq() + }; + calc_other_times_ms = NumberSeq(summary->get_total_seq(), + 1, other_parts); + } + check_other_times(1, summary->get_other_seq(), &calc_other_times_ms); + } + } else { + print_indent(0); + gclog_or_tty->print_cr("none"); + } + gclog_or_tty->print_cr(""); +} + +void +G1CollectorPolicy::print_abandoned_summary(PauseSummary* non_pop_summary, + PauseSummary* pop_summary) const { + bool printed = false; + if (non_pop_summary->get_total_seq()->num() > 0) { + printed = true; + print_summary(non_pop_summary); + } + if (pop_summary->get_total_seq()->num() > 0) { + printed = true; + print_summary(pop_summary); + } + + if (!printed) { + print_indent(0); + gclog_or_tty->print_cr("none"); + gclog_or_tty->print_cr(""); + } +} + +void G1CollectorPolicy::print_tracing_info() const { + if (TraceGen0Time) { + gclog_or_tty->print_cr("ALL PAUSES"); + print_summary_sd(0, "Total", _all_pause_times_ms); + gclog_or_tty->print_cr(""); + gclog_or_tty->print_cr(""); + gclog_or_tty->print_cr(" Full Young GC Pauses: %8d", _full_young_pause_num); + gclog_or_tty->print_cr(" Partial Young GC Pauses: %8d", _partial_young_pause_num); + gclog_or_tty->print_cr(""); + + gclog_or_tty->print_cr("NON-POPULAR PAUSES"); + print_summary(_non_pop_summary); + + gclog_or_tty->print_cr("POPULAR PAUSES"); + print_summary(_pop_summary); + + gclog_or_tty->print_cr("ABANDONED PAUSES"); + print_abandoned_summary(_non_pop_abandoned_summary, + _pop_abandoned_summary); + + gclog_or_tty->print_cr("MISC"); + print_summary_sd(0, "Stop World", _all_stop_world_times_ms); + print_summary_sd(0, "Yields", _all_yield_times_ms); + for (int i = 0; i < _aux_num; ++i) { + if (_all_aux_times_ms[i].num() > 0) { + char buffer[96]; + sprintf(buffer, "Aux%d", i); + print_summary_sd(0, buffer, &_all_aux_times_ms[i]); + } + } + + size_t all_region_num = _region_num_young + _region_num_tenured; + gclog_or_tty->print_cr(" New Regions %8d, Young %8d (%6.2lf%%), " + "Tenured %8d (%6.2lf%%)", + all_region_num, + _region_num_young, + (double) _region_num_young / (double) all_region_num * 100.0, + _region_num_tenured, + (double) _region_num_tenured / (double) all_region_num * 100.0); + + if (!G1RSBarrierUseQueue) { + gclog_or_tty->print_cr("Of %d times conc refinement was enabled, %d (%7.2f%%) " + "did zero traversals.", + _conc_refine_enabled, _conc_refine_zero_traversals, + _conc_refine_enabled > 0 ? + 100.0 * (float)_conc_refine_zero_traversals/ + (float)_conc_refine_enabled : 0.0); + gclog_or_tty->print_cr(" Max # of traversals = %d.", + _conc_refine_max_traversals); + gclog_or_tty->print_cr(""); + } + } + if (TraceGen1Time) { + if (_all_full_gc_times_ms->num() > 0) { + gclog_or_tty->print("\n%4d full_gcs: total time = %8.2f s", + _all_full_gc_times_ms->num(), + _all_full_gc_times_ms->sum() / 1000.0); + gclog_or_tty->print_cr(" (avg = %8.2fms).", _all_full_gc_times_ms->avg()); + gclog_or_tty->print_cr(" [std. dev = %8.2f ms, max = %8.2f ms]", + _all_full_gc_times_ms->sd(), + _all_full_gc_times_ms->maximum()); + } + } +} + +void G1CollectorPolicy::print_yg_surv_rate_info() const { +#ifndef PRODUCT + _short_lived_surv_rate_group->print_surv_rate_summary(); + // add this call for any other surv rate groups +#endif // PRODUCT +} + +void G1CollectorPolicy::update_conc_refine_data() { + unsigned traversals = _g1->concurrent_g1_refine()->disable(); + if (traversals == 0) _conc_refine_zero_traversals++; + _conc_refine_max_traversals = MAX2(_conc_refine_max_traversals, + (size_t)traversals); + + if (G1PolicyVerbose > 1) + gclog_or_tty->print_cr("Did a CR traversal series: %d traversals.", traversals); + double multiplier = 1.0; + if (traversals == 0) { + multiplier = 4.0; + } else if (traversals > (size_t)G1ConcRefineTargTraversals) { + multiplier = 1.0/1.5; + } else if (traversals < (size_t)G1ConcRefineTargTraversals) { + multiplier = 1.5; + } + if (G1PolicyVerbose > 1) { + gclog_or_tty->print_cr(" Multiplier = %7.2f.", multiplier); + gclog_or_tty->print(" Delta went from %d regions to ", + _conc_refine_current_delta); + } + _conc_refine_current_delta = + MIN2(_g1->n_regions(), + (size_t)(_conc_refine_current_delta * multiplier)); + _conc_refine_current_delta = + MAX2(_conc_refine_current_delta, (size_t)1); + if (G1PolicyVerbose > 1) { + gclog_or_tty->print_cr("%d regions.", _conc_refine_current_delta); + } + _conc_refine_enabled++; +} + +void G1CollectorPolicy::set_single_region_collection_set(HeapRegion* hr) { + assert(collection_set() == NULL, "Must be no current CS."); + _collection_set_size = 0; + _collection_set_bytes_used_before = 0; + add_to_collection_set(hr); + count_CS_bytes_used(); +} + +bool +G1CollectorPolicy::should_add_next_region_to_young_list() { + assert(in_young_gc_mode(), "should be in young GC mode"); + bool ret; + size_t young_list_length = _g1->young_list_length(); + + if (young_list_length < _young_list_target_length) { + ret = true; + ++_region_num_young; + } else { + ret = false; + ++_region_num_tenured; + } + + return ret; +} + +#ifndef PRODUCT +// for debugging, bit of a hack... +static char* +region_num_to_mbs(int length) { + static char buffer[64]; + double bytes = (double) (length * HeapRegion::GrainBytes); + double mbs = bytes / (double) (1024 * 1024); + sprintf(buffer, "%7.2lfMB", mbs); + return buffer; +} +#endif // PRODUCT + +void +G1CollectorPolicy::checkpoint_conc_overhead() { + double conc_overhead = 0.0; + if (G1AccountConcurrentOverhead) + conc_overhead = COTracker::totalPredConcOverhead(); + _mmu_tracker->update_conc_overhead(conc_overhead); +#if 0 + gclog_or_tty->print(" CO %1.4lf TARGET %1.4lf", + conc_overhead, _mmu_tracker->max_gc_time()); +#endif +} + + +uint G1CollectorPolicy::max_regions(int purpose) { + switch (purpose) { + case GCAllocForSurvived: + return G1MaxSurvivorRegions; + case GCAllocForTenured: + return UINT_MAX; + default: + return UINT_MAX; + }; +} + +void +G1CollectorPolicy_BestRegionsFirst:: +set_single_region_collection_set(HeapRegion* hr) { + G1CollectorPolicy::set_single_region_collection_set(hr); + _collectionSetChooser->removeRegion(hr); +} + + +bool +G1CollectorPolicy_BestRegionsFirst::should_do_collection_pause(size_t + word_size) { + assert(_g1->regions_accounted_for(), "Region leakage!"); + // Initiate a pause when we reach the steady-state "used" target. + size_t used_hard = (_g1->capacity() / 100) * G1SteadyStateUsed; + size_t used_soft = + MAX2((_g1->capacity() / 100) * (G1SteadyStateUsed - G1SteadyStateUsedDelta), + used_hard/2); + size_t used = _g1->used(); + + double max_pause_time_ms = _mmu_tracker->max_gc_time() * 1000.0; + + size_t young_list_length = _g1->young_list_length(); + bool reached_target_length = young_list_length >= _young_list_target_length; + + if (in_young_gc_mode()) { + if (reached_target_length) { + assert( young_list_length > 0 && _g1->young_list_length() > 0, + "invariant" ); + _target_pause_time_ms = max_pause_time_ms; + return true; + } + } else { + guarantee( false, "should not reach here" ); + } + + return false; +} + +#ifndef PRODUCT +class HRSortIndexIsOKClosure: public HeapRegionClosure { + CollectionSetChooser* _chooser; +public: + HRSortIndexIsOKClosure(CollectionSetChooser* chooser) : + _chooser(chooser) {} + + bool doHeapRegion(HeapRegion* r) { + if (!r->continuesHumongous()) { + assert(_chooser->regionProperlyOrdered(r), "Ought to be."); + } + return false; + } +}; + +bool G1CollectorPolicy_BestRegionsFirst::assertMarkedBytesDataOK() { + HRSortIndexIsOKClosure cl(_collectionSetChooser); + _g1->heap_region_iterate(&cl); + return true; +} +#endif + +void +G1CollectorPolicy_BestRegionsFirst:: +record_collection_pause_start(double start_time_sec, size_t start_used) { + G1CollectorPolicy::record_collection_pause_start(start_time_sec, start_used); +} + +class NextNonCSElemFinder: public HeapRegionClosure { + HeapRegion* _res; +public: + NextNonCSElemFinder(): _res(NULL) {} + bool doHeapRegion(HeapRegion* r) { + if (!r->in_collection_set()) { + _res = r; + return true; + } else { + return false; + } + } + HeapRegion* res() { return _res; } +}; + +class KnownGarbageClosure: public HeapRegionClosure { + CollectionSetChooser* _hrSorted; + +public: + KnownGarbageClosure(CollectionSetChooser* hrSorted) : + _hrSorted(hrSorted) + {} + + bool doHeapRegion(HeapRegion* r) { + // We only include humongous regions in collection + // sets when concurrent mark shows that their contained object is + // unreachable. + + // Do we have any marking information for this region? + if (r->is_marked()) { + // We don't include humongous regions in collection + // sets because we collect them immediately at the end of a marking + // cycle. We also don't include young regions because we *must* + // include them in the next collection pause. + if (!r->isHumongous() && !r->is_young()) { + _hrSorted->addMarkedHeapRegion(r); + } + } + return false; + } +}; + +class ParKnownGarbageHRClosure: public HeapRegionClosure { + CollectionSetChooser* _hrSorted; + jint _marked_regions_added; + jint _chunk_size; + jint _cur_chunk_idx; + jint _cur_chunk_end; // Cur chunk [_cur_chunk_idx, _cur_chunk_end) + int _worker; + int _invokes; + + void get_new_chunk() { + _cur_chunk_idx = _hrSorted->getParMarkedHeapRegionChunk(_chunk_size); + _cur_chunk_end = _cur_chunk_idx + _chunk_size; + } + void add_region(HeapRegion* r) { + if (_cur_chunk_idx == _cur_chunk_end) { + get_new_chunk(); + } + assert(_cur_chunk_idx < _cur_chunk_end, "postcondition"); + _hrSorted->setMarkedHeapRegion(_cur_chunk_idx, r); + _marked_regions_added++; + _cur_chunk_idx++; + } + +public: + ParKnownGarbageHRClosure(CollectionSetChooser* hrSorted, + jint chunk_size, + int worker) : + _hrSorted(hrSorted), _chunk_size(chunk_size), _worker(worker), + _marked_regions_added(0), _cur_chunk_idx(0), _cur_chunk_end(0), + _invokes(0) + {} + + bool doHeapRegion(HeapRegion* r) { + // We only include humongous regions in collection + // sets when concurrent mark shows that their contained object is + // unreachable. + _invokes++; + + // Do we have any marking information for this region? + if (r->is_marked()) { + // We don't include humongous regions in collection + // sets because we collect them immediately at the end of a marking + // cycle. + // We also do not include young regions in collection sets + if (!r->isHumongous() && !r->is_young()) { + add_region(r); + } + } + return false; + } + jint marked_regions_added() { return _marked_regions_added; } + int invokes() { return _invokes; } +}; + +class ParKnownGarbageTask: public AbstractGangTask { + CollectionSetChooser* _hrSorted; + jint _chunk_size; + G1CollectedHeap* _g1; +public: + ParKnownGarbageTask(CollectionSetChooser* hrSorted, jint chunk_size) : + AbstractGangTask("ParKnownGarbageTask"), + _hrSorted(hrSorted), _chunk_size(chunk_size), + _g1(G1CollectedHeap::heap()) + {} + + void work(int i) { + ParKnownGarbageHRClosure parKnownGarbageCl(_hrSorted, _chunk_size, i); + // Back to zero for the claim value. + _g1->heap_region_par_iterate_chunked(&parKnownGarbageCl, i, 0); + jint regions_added = parKnownGarbageCl.marked_regions_added(); + _hrSorted->incNumMarkedHeapRegions(regions_added); + if (G1PrintParCleanupStats) { + gclog_or_tty->print(" Thread %d called %d times, added %d regions to list.\n", + i, parKnownGarbageCl.invokes(), regions_added); + } + } +}; + +void +G1CollectorPolicy_BestRegionsFirst:: +record_concurrent_mark_cleanup_end(size_t freed_bytes, + size_t max_live_bytes) { + double start; + if (G1PrintParCleanupStats) start = os::elapsedTime(); + record_concurrent_mark_cleanup_end_work1(freed_bytes, max_live_bytes); + + _collectionSetChooser->clearMarkedHeapRegions(); + double clear_marked_end; + if (G1PrintParCleanupStats) { + clear_marked_end = os::elapsedTime(); + gclog_or_tty->print_cr(" clear marked regions + work1: %8.3f ms.", + (clear_marked_end - start)*1000.0); + } + if (ParallelGCThreads > 0) { + const size_t OverpartitionFactor = 4; + const size_t MinChunkSize = 8; + const size_t ChunkSize = + MAX2(_g1->n_regions() / (ParallelGCThreads * OverpartitionFactor), + MinChunkSize); + _collectionSetChooser->prepareForAddMarkedHeapRegionsPar(_g1->n_regions(), + ChunkSize); + ParKnownGarbageTask parKnownGarbageTask(_collectionSetChooser, + (int) ChunkSize); + _g1->workers()->run_task(&parKnownGarbageTask); + } else { + KnownGarbageClosure knownGarbagecl(_collectionSetChooser); + _g1->heap_region_iterate(&knownGarbagecl); + } + double known_garbage_end; + if (G1PrintParCleanupStats) { + known_garbage_end = os::elapsedTime(); + gclog_or_tty->print_cr(" compute known garbage: %8.3f ms.", + (known_garbage_end - clear_marked_end)*1000.0); + } + _collectionSetChooser->sortMarkedHeapRegions(); + double sort_end; + if (G1PrintParCleanupStats) { + sort_end = os::elapsedTime(); + gclog_or_tty->print_cr(" sorting: %8.3f ms.", + (sort_end - known_garbage_end)*1000.0); + } + + record_concurrent_mark_cleanup_end_work2(); + double work2_end; + if (G1PrintParCleanupStats) { + work2_end = os::elapsedTime(); + gclog_or_tty->print_cr(" work2: %8.3f ms.", + (work2_end - sort_end)*1000.0); + } +} + +// Add the heap region to the collection set and return the conservative +// estimate of the number of live bytes. +void G1CollectorPolicy:: +add_to_collection_set(HeapRegion* hr) { + if (G1TraceRegions) { + gclog_or_tty->print_cr("added region to cset %d:["PTR_FORMAT", "PTR_FORMAT"], " + "top "PTR_FORMAT", young %s", + hr->hrs_index(), hr->bottom(), hr->end(), + hr->top(), (hr->is_young()) ? "YES" : "NO"); + } + + if (_g1->mark_in_progress()) + _g1->concurrent_mark()->registerCSetRegion(hr); + + assert(!hr->in_collection_set(), + "should not already be in the CSet"); + hr->set_in_collection_set(true); + hr->set_next_in_collection_set(_collection_set); + _collection_set = hr; + _collection_set_size++; + _collection_set_bytes_used_before += hr->used(); +} + +void +G1CollectorPolicy_BestRegionsFirst:: +choose_collection_set(HeapRegion* pop_region) { + double non_young_start_time_sec; + start_recording_regions(); + + if (pop_region != NULL) { + _target_pause_time_ms = (double) G1MaxPauseTimeMS; + } else { + guarantee(_target_pause_time_ms > -1.0, + "_target_pause_time_ms should have been set!"); + } + + // pop region is either null (and so is CS), or else it *is* the CS. + assert(_collection_set == pop_region, "Precondition"); + + double base_time_ms = predict_base_elapsed_time_ms(_pending_cards); + double predicted_pause_time_ms = base_time_ms; + + double target_time_ms = _target_pause_time_ms; + double time_remaining_ms = target_time_ms - base_time_ms; + + // the 10% and 50% values are arbitrary... + if (time_remaining_ms < 0.10*target_time_ms) { + time_remaining_ms = 0.50 * target_time_ms; + _within_target = false; + } else { + _within_target = true; + } + + // We figure out the number of bytes available for future to-space. + // For new regions without marking information, we must assume the + // worst-case of complete survival. If we have marking information for a + // region, we can bound the amount of live data. We can add a number of + // such regions, as long as the sum of the live data bounds does not + // exceed the available evacuation space. + size_t max_live_bytes = _g1->free_regions() * HeapRegion::GrainBytes; + + size_t expansion_bytes = + _g1->expansion_regions() * HeapRegion::GrainBytes; + + if (pop_region == NULL) { + _collection_set_bytes_used_before = 0; + _collection_set_size = 0; + } + + // Adjust for expansion and slop. + max_live_bytes = max_live_bytes + expansion_bytes; + + assert(pop_region != NULL || _g1->regions_accounted_for(), "Region leakage!"); + + HeapRegion* hr; + if (in_young_gc_mode()) { + double young_start_time_sec = os::elapsedTime(); + + if (G1PolicyVerbose > 0) { + gclog_or_tty->print_cr("Adding %d young regions to the CSet", + _g1->young_list_length()); + } + _young_cset_length = 0; + _last_young_gc_full = full_young_gcs() ? true : false; + if (_last_young_gc_full) + ++_full_young_pause_num; + else + ++_partial_young_pause_num; + hr = _g1->pop_region_from_young_list(); + while (hr != NULL) { + + assert( hr->young_index_in_cset() == -1, "invariant" ); + assert( hr->age_in_surv_rate_group() != -1, "invariant" ); + hr->set_young_index_in_cset((int) _young_cset_length); + + ++_young_cset_length; + double predicted_time_ms = predict_region_elapsed_time_ms(hr, true); + time_remaining_ms -= predicted_time_ms; + predicted_pause_time_ms += predicted_time_ms; + if (hr == pop_region) { + // The popular region was young. Skip over it. + assert(hr->in_collection_set(), "It's the pop region."); + } else { + assert(!hr->in_collection_set(), "It's not the pop region."); + add_to_collection_set(hr); + record_cset_region(hr, true); + } + max_live_bytes -= MIN2(hr->max_live_bytes(), max_live_bytes); + if (G1PolicyVerbose > 0) { + gclog_or_tty->print_cr(" Added [" PTR_FORMAT ", " PTR_FORMAT") to CS.", + hr->bottom(), hr->end()); + gclog_or_tty->print_cr(" (" SIZE_FORMAT " KB left in heap.)", + max_live_bytes/K); + } + hr = _g1->pop_region_from_young_list(); + } + + record_scan_only_regions(_g1->young_list_scan_only_length()); + + double young_end_time_sec = os::elapsedTime(); + _recorded_young_cset_choice_time_ms = + (young_end_time_sec - young_start_time_sec) * 1000.0; + + non_young_start_time_sec = os::elapsedTime(); + + if (_young_cset_length > 0 && _last_young_gc_full) { + // don't bother adding more regions... + goto choose_collection_set_end; + } + } else if (pop_region != NULL) { + // We're not in young mode, and we chose a popular region; don't choose + // any more. + return; + } + + if (!in_young_gc_mode() || !full_young_gcs()) { + bool should_continue = true; + NumberSeq seq; + double avg_prediction = 100000000000000000.0; // something very large + do { + hr = _collectionSetChooser->getNextMarkedRegion(time_remaining_ms, + avg_prediction); + if (hr != NULL && !hr->popular()) { + double predicted_time_ms = predict_region_elapsed_time_ms(hr, false); + time_remaining_ms -= predicted_time_ms; + predicted_pause_time_ms += predicted_time_ms; + add_to_collection_set(hr); + record_cset_region(hr, false); + max_live_bytes -= MIN2(hr->max_live_bytes(), max_live_bytes); + if (G1PolicyVerbose > 0) { + gclog_or_tty->print_cr(" (" SIZE_FORMAT " KB left in heap.)", + max_live_bytes/K); + } + seq.add(predicted_time_ms); + avg_prediction = seq.avg() + seq.sd(); + } + should_continue = + ( hr != NULL) && + ( (adaptive_young_list_length()) ? time_remaining_ms > 0.0 + : _collection_set_size < _young_list_fixed_length ); + } while (should_continue); + + if (!adaptive_young_list_length() && + _collection_set_size < _young_list_fixed_length) + _should_revert_to_full_young_gcs = true; + } + +choose_collection_set_end: + count_CS_bytes_used(); + + end_recording_regions(); + + double non_young_end_time_sec = os::elapsedTime(); + _recorded_non_young_cset_choice_time_ms = + (non_young_end_time_sec - non_young_start_time_sec) * 1000.0; +} + +void G1CollectorPolicy_BestRegionsFirst::record_full_collection_end() { + G1CollectorPolicy::record_full_collection_end(); + _collectionSetChooser->updateAfterFullCollection(); +} + +void G1CollectorPolicy_BestRegionsFirst:: +expand_if_possible(size_t numRegions) { + size_t expansion_bytes = numRegions * HeapRegion::GrainBytes; + _g1->expand(expansion_bytes); +} + +void G1CollectorPolicy_BestRegionsFirst:: +record_collection_pause_end(bool popular, bool abandoned) { + G1CollectorPolicy::record_collection_pause_end(popular, abandoned); + assert(assertMarkedBytesDataOK(), "Marked regions not OK at pause end."); +} + +// Local Variables: *** +// c-indentation-style: gnu *** +// End: ***