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src/hotspot/share/gc/g1/g1CollectionSet.cpp

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*** 57,71 **** _survivor_region_length(0), _old_region_length(0), _collection_set_regions(NULL), _collection_set_cur_length(0), _collection_set_max_length(0), ! _num_optional_regions(0), _bytes_used_before(0), _recorded_rs_lengths(0), _inc_build_state(Inactive), - _inc_part_start(0), _inc_bytes_used_before(0), _inc_recorded_rs_lengths(0), _inc_recorded_rs_lengths_diffs(0), _inc_predicted_elapsed_time_ms(0.0), _inc_predicted_elapsed_time_ms_diffs(0.0) { --- 57,72 ---- _survivor_region_length(0), _old_region_length(0), _collection_set_regions(NULL), _collection_set_cur_length(0), _collection_set_max_length(0), ! _optional_regions(NULL), ! _optional_region_length(0), ! _optional_region_max_length(0), _bytes_used_before(0), _recorded_rs_lengths(0), _inc_build_state(Inactive), _inc_bytes_used_before(0), _inc_recorded_rs_lengths(0), _inc_recorded_rs_lengths_diffs(0), _inc_predicted_elapsed_time_ms(0.0), _inc_predicted_elapsed_time_ms_diffs(0.0) {
*** 87,108 **** _survivor_region_length = survivor_cset_region_length; assert((size_t) young_region_length() == _collection_set_cur_length, "Young region length %u should match collection set length " SIZE_FORMAT, young_region_length(), _collection_set_cur_length); ! _old_region_length = 0; ! free_optional_regions(); } void G1CollectionSet::initialize(uint max_region_length) { guarantee(_collection_set_regions == NULL, "Must only initialize once."); _collection_set_max_length = max_region_length; _collection_set_regions = NEW_C_HEAP_ARRAY(uint, max_region_length, mtGC); } void G1CollectionSet::free_optional_regions() { ! _num_optional_regions = 0; } void G1CollectionSet::clear_candidates() { delete _candidates; _candidates = NULL; --- 88,122 ---- _survivor_region_length = survivor_cset_region_length; assert((size_t) young_region_length() == _collection_set_cur_length, "Young region length %u should match collection set length " SIZE_FORMAT, young_region_length(), _collection_set_cur_length); ! _old_region_length = 0; ! _optional_region_length = 0; } void G1CollectionSet::initialize(uint max_region_length) { guarantee(_collection_set_regions == NULL, "Must only initialize once."); _collection_set_max_length = max_region_length; _collection_set_regions = NEW_C_HEAP_ARRAY(uint, max_region_length, mtGC); } + void G1CollectionSet::initialize_optional(uint max_length) { + assert(_optional_regions == NULL, "Already initialized"); + assert(_optional_region_length == 0, "Already initialized"); + assert(_optional_region_max_length == 0, "Already initialized"); + _optional_region_max_length = max_length; + _optional_regions = NEW_C_HEAP_ARRAY(HeapRegion*, _optional_region_max_length, mtGC); + } + void G1CollectionSet::free_optional_regions() { ! _optional_region_length = 0; ! _optional_region_max_length = 0; ! if (_optional_regions != NULL) { ! FREE_C_HEAP_ARRAY(HeapRegion*, _optional_regions); ! _optional_regions = NULL; ! } } void G1CollectionSet::clear_candidates() { delete _candidates; _candidates = NULL;
*** 114,161 **** // Add the heap region at the head of the non-incremental collection set void G1CollectionSet::add_old_region(HeapRegion* hr) { assert_at_safepoint_on_vm_thread(); ! assert(_inc_build_state == Active, "Precondition, actively building cset or adding optional later on"); assert(hr->is_old(), "the region should be old"); ! assert(!hr->in_collection_set(), "should not already be in the collection set"); ! _g1h->register_old_region_with_region_attr(hr); _collection_set_regions[_collection_set_cur_length++] = hr->hrm_index(); assert(_collection_set_cur_length <= _collection_set_max_length, "Collection set now larger than maximum size."); _bytes_used_before += hr->used(); ! _recorded_rs_lengths += hr->rem_set()->occupied(); ! _old_region_length++; ! _g1h->old_set_remove(hr); } void G1CollectionSet::add_optional_region(HeapRegion* hr) { assert(hr->is_old(), "the region should be old"); assert(!hr->in_collection_set(), "should not already be in the CSet"); ! _g1h->register_optional_region_with_region_attr(hr); ! hr->set_index_in_opt_cset(_num_optional_regions++); } void G1CollectionSet::start_incremental_building() { assert(_collection_set_cur_length == 0, "Collection set must be empty before starting a new collection set."); assert(_inc_build_state == Inactive, "Precondition"); _inc_bytes_used_before = 0; _inc_recorded_rs_lengths = 0; _inc_recorded_rs_lengths_diffs = 0; _inc_predicted_elapsed_time_ms = 0.0; _inc_predicted_elapsed_time_ms_diffs = 0.0; ! ! update_incremental_marker(); } void G1CollectionSet::finalize_incremental_building() { assert(_inc_build_state == Active, "Precondition"); assert(SafepointSynchronize::is_at_safepoint(), "should be at a safepoint"); --- 128,181 ---- // Add the heap region at the head of the non-incremental collection set void G1CollectionSet::add_old_region(HeapRegion* hr) { assert_at_safepoint_on_vm_thread(); ! assert(_inc_build_state == Active || hr->index_in_opt_cset() != G1OptionalCSet::InvalidCSetIndex, "Precondition, actively building cset or adding optional later on"); assert(hr->is_old(), "the region should be old"); ! assert(!hr->in_collection_set(), "should not already be in the CSet"); ! _g1h->register_old_region_with_cset(hr); _collection_set_regions[_collection_set_cur_length++] = hr->hrm_index(); assert(_collection_set_cur_length <= _collection_set_max_length, "Collection set now larger than maximum size."); _bytes_used_before += hr->used(); ! size_t rs_length = hr->rem_set()->occupied(); ! _recorded_rs_lengths += rs_length; ! _old_region_length += 1; ! log_trace(gc, cset)("Added old region %d to collection set", hr->hrm_index()); } void G1CollectionSet::add_optional_region(HeapRegion* hr) { + assert(!optional_is_full(), "Precondition, must have room left for this region"); assert(hr->is_old(), "the region should be old"); assert(!hr->in_collection_set(), "should not already be in the CSet"); ! _g1h->register_optional_region_with_cset(hr); ! _optional_regions[_optional_region_length] = hr; ! uint index = _optional_region_length++; ! hr->set_index_in_opt_cset(index); ! ! log_trace(gc, cset)("Added region %d to optional collection set (%u)", hr->hrm_index(), _optional_region_length); } + // Initialize the per-collection-set information void G1CollectionSet::start_incremental_building() { assert(_collection_set_cur_length == 0, "Collection set must be empty before starting a new collection set."); assert(_inc_build_state == Inactive, "Precondition"); _inc_bytes_used_before = 0; _inc_recorded_rs_lengths = 0; _inc_recorded_rs_lengths_diffs = 0; _inc_predicted_elapsed_time_ms = 0.0; _inc_predicted_elapsed_time_ms_diffs = 0.0; ! _inc_build_state = Active; } void G1CollectionSet::finalize_incremental_building() { assert(_inc_build_state == Active, "Precondition"); assert(SafepointSynchronize::is_at_safepoint(), "should be at a safepoint");
*** 189,240 **** } void G1CollectionSet::clear() { assert_at_safepoint_on_vm_thread(); _collection_set_cur_length = 0; } void G1CollectionSet::iterate(HeapRegionClosure* cl) const { ! size_t len = _collection_set_cur_length; ! OrderAccess::loadload(); ! ! for (uint i = 0; i < len; i++) { ! HeapRegion* r = _g1h->region_at(_collection_set_regions[i]); ! bool result = cl->do_heap_region(r); ! if (result) { ! cl->set_incomplete(); ! return; ! } ! } ! } ! ! void G1CollectionSet::iterate_optional(HeapRegionClosure* cl) const { ! assert_at_safepoint(); ! ! for (uint i = 0; i < _num_optional_regions; i++) { ! HeapRegion* r = _candidates->at(i); ! bool result = cl->do_heap_region(r); ! guarantee(!result, "Must not cancel iteration"); ! } } ! void G1CollectionSet::iterate_incremental_part_from(HeapRegionClosure* cl, uint worker_id, uint total_workers) const { ! assert_at_safepoint(); ! ! size_t len = _collection_set_cur_length - _inc_part_start; if (len == 0) { return; } - size_t start_pos = (worker_id * len) / total_workers; size_t cur_pos = start_pos; do { ! HeapRegion* r = _g1h->region_at(_collection_set_regions[cur_pos + _inc_part_start]); bool result = cl->do_heap_region(r); ! guarantee(!result, "Must not cancel iteration"); ! cur_pos++; if (cur_pos == len) { cur_pos = 0; } } while (cur_pos != start_pos); --- 209,241 ---- } void G1CollectionSet::clear() { assert_at_safepoint_on_vm_thread(); _collection_set_cur_length = 0; + _optional_region_length = 0; } void G1CollectionSet::iterate(HeapRegionClosure* cl) const { ! iterate_from(cl, 0, 1); } ! void G1CollectionSet::iterate_from(HeapRegionClosure* cl, uint worker_id, uint total_workers) const { ! size_t len = _collection_set_cur_length; ! OrderAccess::loadload(); if (len == 0) { return; } size_t start_pos = (worker_id * len) / total_workers; size_t cur_pos = start_pos; do { ! HeapRegion* r = _g1h->region_at(_collection_set_regions[cur_pos]); bool result = cl->do_heap_region(r); ! if (result) { ! cl->set_incomplete(); ! return; ! } cur_pos++; if (cur_pos == len) { cur_pos = 0; } } while (cur_pos != start_pos);
*** 314,324 **** _inc_predicted_elapsed_time_ms += region_elapsed_time_ms; _inc_bytes_used_before += hr->used(); } assert(!hr->in_collection_set(), "invariant"); ! _g1h->register_young_region_with_region_attr(hr); } void G1CollectionSet::add_survivor_regions(HeapRegion* hr) { assert(hr->is_survivor(), "Must only add survivor regions, but is %s", hr->get_type_str()); add_young_region_common(hr); --- 315,325 ---- _inc_predicted_elapsed_time_ms += region_elapsed_time_ms; _inc_bytes_used_before += hr->used(); } assert(!hr->in_collection_set(), "invariant"); ! _g1h->register_young_region_with_cset(hr); } void G1CollectionSet::add_survivor_regions(HeapRegion* hr) { assert(hr->is_survivor(), "Must only add survivor regions, but is %s", hr->get_type_str()); add_young_region_common(hr);
*** 437,446 **** --- 438,471 ---- phase_times()->record_young_cset_choice_time_ms((young_end_time_sec - young_start_time_sec) * 1000.0); return time_remaining_ms; } + void G1CollectionSet::add_as_old(HeapRegion* hr) { + candidates()->pop_front(); // already have region via peek() + _g1h->old_set_remove(hr); + add_old_region(hr); + } + + void G1CollectionSet::add_as_optional(HeapRegion* hr) { + assert(_optional_regions != NULL, "Must not be called before array is allocated"); + candidates()->pop_front(); // already have region via peek() + _g1h->old_set_remove(hr); + add_optional_region(hr); + } + + bool G1CollectionSet::optional_is_full() { + assert(_optional_region_length <= _optional_region_max_length, "Invariant"); + return _optional_region_length == _optional_region_max_length; + } + + void G1CollectionSet::clear_optional_region(const HeapRegion* hr) { + assert(_optional_regions != NULL, "Must not be called before array is allocated"); + uint index = hr->index_in_opt_cset(); + _optional_regions[index] = NULL; + } + static int compare_region_idx(const uint a, const uint b) { if (a > b) { return 1; } else if (a == b) { return 0;
*** 449,537 **** } } void G1CollectionSet::finalize_old_part(double time_remaining_ms) { double non_young_start_time_sec = os::elapsedTime(); if (collector_state()->in_mixed_phase()) { candidates()->verify(); ! ! uint num_initial_old_regions; ! uint num_optional_old_regions; ! ! _policy->calculate_old_collection_set_regions(candidates(), ! time_remaining_ms, ! num_initial_old_regions, ! num_optional_old_regions); ! ! // Prepare initial old regions. ! move_candidates_to_collection_set(num_initial_old_regions); ! ! // Prepare optional old regions for evacuation. ! uint candidate_idx = candidates()->cur_idx(); ! for (uint i = 0; i < num_optional_old_regions; i++) { ! add_optional_region(candidates()->at(candidate_idx + i)); } candidates()->verify(); } stop_incremental_building(); double non_young_end_time_sec = os::elapsedTime(); phase_times()->record_non_young_cset_choice_time_ms((non_young_end_time_sec - non_young_start_time_sec) * 1000.0); QuickSort::sort(_collection_set_regions, _collection_set_cur_length, compare_region_idx, true); } ! void G1CollectionSet::move_candidates_to_collection_set(uint num_old_candidate_regions) { ! if (num_old_candidate_regions == 0) { ! return; ! } ! uint candidate_idx = candidates()->cur_idx(); ! for (uint i = 0; i < num_old_candidate_regions; i++) { ! HeapRegion* r = candidates()->at(candidate_idx + i); ! // This potentially optional candidate region is going to be an actual collection ! // set region. Clear cset marker. ! _g1h->clear_region_attr(r); ! add_old_region(r); } - candidates()->remove(num_old_candidate_regions); ! candidates()->verify(); } ! void G1CollectionSet::finalize_initial_collection_set(double target_pause_time_ms, G1SurvivorRegions* survivor) { ! double time_remaining_ms = finalize_young_part(target_pause_time_ms, survivor); ! finalize_old_part(time_remaining_ms); } ! bool G1CollectionSet::finalize_optional_for_evacuation(double remaining_pause_time) { ! update_incremental_marker(); ! uint num_selected_regions; ! _policy->calculate_optional_collection_set_regions(candidates(), ! _num_optional_regions, ! remaining_pause_time, ! num_selected_regions); ! move_candidates_to_collection_set(num_selected_regions); ! _num_optional_regions -= num_selected_regions; ! stop_incremental_building(); ! return num_selected_regions > 0; } ! void G1CollectionSet::abandon_optional_collection_set(G1ParScanThreadStateSet* pss) { ! for (uint i = 0; i < _num_optional_regions; i++) { ! HeapRegion* r = candidates()->at(candidates()->cur_idx() + i); ! pss->record_unused_optional_region(r); ! _g1h->clear_region_attr(r); ! r->clear_index_in_opt_cset(); ! } ! free_optional_regions(); } #ifdef ASSERT class G1VerifyYoungCSetIndicesClosure : public HeapRegionClosure { private: --- 474,664 ---- } } void G1CollectionSet::finalize_old_part(double time_remaining_ms) { double non_young_start_time_sec = os::elapsedTime(); + double predicted_old_time_ms = 0.0; + double predicted_optional_time_ms = 0.0; + double optional_threshold_ms = time_remaining_ms * _policy->optional_prediction_fraction(); + uint expensive_region_num = 0; if (collector_state()->in_mixed_phase()) { candidates()->verify(); ! const uint min_old_cset_length = _policy->calc_min_old_cset_length(); ! const uint max_old_cset_length = MAX2(min_old_cset_length, _policy->calc_max_old_cset_length()); ! bool check_time_remaining = _policy->adaptive_young_list_length(); ! ! initialize_optional(max_old_cset_length - min_old_cset_length); ! log_debug(gc, ergo, cset)("Start adding old regions for mixed gc. min %u regions, max %u regions, " ! "time remaining %1.2fms, optional threshold %1.2fms", ! min_old_cset_length, max_old_cset_length, time_remaining_ms, optional_threshold_ms); ! ! HeapRegion* hr = candidates()->peek_front(); ! while (hr != NULL) { ! if (old_region_length() + optional_region_length() >= max_old_cset_length) { ! // Added maximum number of old regions to the CSet. ! log_debug(gc, ergo, cset)("Finish adding old regions to CSet (old CSet region num reached max). " ! "old %u regions, optional %u regions", ! old_region_length(), optional_region_length()); ! break; ! } ! ! // Stop adding regions if the remaining reclaimable space is ! // not above G1HeapWastePercent. ! size_t reclaimable_bytes = candidates()->remaining_reclaimable_bytes(); ! double reclaimable_percent = _policy->reclaimable_bytes_percent(reclaimable_bytes); ! double threshold = (double) G1HeapWastePercent; ! if (reclaimable_percent <= threshold) { ! // We've added enough old regions that the amount of uncollected ! // reclaimable space is at or below the waste threshold. Stop ! // adding old regions to the CSet. ! log_debug(gc, ergo, cset)("Finish adding old regions to CSet (reclaimable percentage not over threshold). " ! "reclaimable: " SIZE_FORMAT "%s (%1.2f%%) threshold: " UINTX_FORMAT "%%", ! byte_size_in_proper_unit(reclaimable_bytes), proper_unit_for_byte_size(reclaimable_bytes), ! reclaimable_percent, G1HeapWastePercent); ! break; ! } ! ! double predicted_time_ms = predict_region_elapsed_time_ms(hr); ! time_remaining_ms = MAX2(time_remaining_ms - predicted_time_ms, 0.0); ! // Add regions to old set until we reach minimum amount ! if (old_region_length() < min_old_cset_length) { ! predicted_old_time_ms += predicted_time_ms; ! add_as_old(hr); ! // Record the number of regions added when no time remaining ! if (time_remaining_ms == 0.0) { ! expensive_region_num++; ! } ! } else { ! // In the non-auto-tuning case, we'll finish adding regions ! // to the CSet if we reach the minimum. ! if (!check_time_remaining) { ! log_debug(gc, ergo, cset)("Finish adding old regions to CSet (old CSet region num reached min)."); ! break; ! } ! // Keep adding regions to old set until we reach optional threshold ! if (time_remaining_ms > optional_threshold_ms) { ! predicted_old_time_ms += predicted_time_ms; ! add_as_old(hr); ! } else if (time_remaining_ms > 0) { ! // Keep adding optional regions until time is up ! if (!optional_is_full()) { ! predicted_optional_time_ms += predicted_time_ms; ! add_as_optional(hr); ! } else { ! log_debug(gc, ergo, cset)("Finish adding old regions to CSet (optional set full)."); ! break; ! } ! } else { ! log_debug(gc, ergo, cset)("Finish adding old regions to CSet (predicted time is too high)."); ! break; ! } ! } ! hr = candidates()->peek_front(); ! } ! if (hr == NULL) { ! log_debug(gc, ergo, cset)("Finish adding old regions to CSet (candidate old regions not available)"); } candidates()->verify(); } stop_incremental_building(); + log_debug(gc, ergo, cset)("Finish choosing CSet regions old: %u, optional: %u, " + "predicted old time: %1.2fms, predicted optional time: %1.2fms, time remaining: %1.2f", + old_region_length(), optional_region_length(), + predicted_old_time_ms, predicted_optional_time_ms, time_remaining_ms); + if (expensive_region_num > 0) { + log_debug(gc, ergo, cset)("CSet contains %u old regions that were added although the predicted time was too high.", + expensive_region_num); + } + double non_young_end_time_sec = os::elapsedTime(); phase_times()->record_non_young_cset_choice_time_ms((non_young_end_time_sec - non_young_start_time_sec) * 1000.0); QuickSort::sort(_collection_set_regions, _collection_set_cur_length, compare_region_idx, true); } ! HeapRegion* G1OptionalCSet::region_at(uint index) { ! return _cset->optional_region_at(index); ! } ! ! void G1OptionalCSet::prepare_evacuation(double time_limit) { ! assert(_current_index == _current_limit, "Before prepare no regions should be ready for evac"); ! ! uint prepared_regions = 0; ! double prediction_ms = 0; ! ! _prepare_failed = true; ! for (uint i = _current_index; i < _cset->optional_region_length(); i++) { ! HeapRegion* hr = region_at(i); ! prediction_ms += _cset->predict_region_elapsed_time_ms(hr); ! if (prediction_ms > time_limit) { ! log_debug(gc, cset)("Prepared %u regions for optional evacuation. Predicted time: %.3fms", prepared_regions, prediction_ms); ! return; ! } ! ! // This region will be included in the next optional evacuation. ! prepare_to_evacuate_optional_region(hr); ! prepared_regions++; ! _current_limit++; ! _prepare_failed = false; } ! log_debug(gc, cset)("Prepared all %u regions for optional evacuation. Predicted time: %.3fms", ! prepared_regions, prediction_ms); } ! bool G1OptionalCSet::prepare_failed() { ! return _prepare_failed; } ! void G1OptionalCSet::complete_evacuation() { ! _evacuation_failed = false; ! for (uint i = _current_index; i < _current_limit; i++) { ! HeapRegion* hr = region_at(i); ! _cset->clear_optional_region(hr); ! if (hr->evacuation_failed()){ ! _evacuation_failed = true; ! } ! } ! _current_index = _current_limit; ! } ! bool G1OptionalCSet::evacuation_failed() { ! return _evacuation_failed; ! } ! G1OptionalCSet::~G1OptionalCSet() { ! G1CollectedHeap* g1h = G1CollectedHeap::heap(); ! while (!is_empty()) { ! // We want to return regions not evacuated to the collection set candidates ! // in reverse order to maintain the old order. ! HeapRegion* hr = _cset->remove_last_optional_region(); ! assert(hr != NULL, "Should be valid region left"); ! _pset->record_unused_optional_region(hr); ! g1h->old_set_add(hr); ! g1h->clear_in_cset(hr); ! hr->set_index_in_opt_cset(InvalidCSetIndex); ! _cset->candidates()->push_front(hr); ! } ! _cset->free_optional_regions(); ! } ! uint G1OptionalCSet::size() { ! return _cset->optional_region_length() - _current_index; ! } ! bool G1OptionalCSet::is_empty() { ! return size() == 0; } ! void G1OptionalCSet::prepare_to_evacuate_optional_region(HeapRegion* hr) { ! log_trace(gc, cset)("Adding region %u for optional evacuation", hr->hrm_index()); ! G1CollectedHeap::heap()->clear_in_cset(hr); ! _cset->add_old_region(hr); } #ifdef ASSERT class G1VerifyYoungCSetIndicesClosure : public HeapRegionClosure { private:
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