# HG changeset patch # User brutisso # Date 1345794308 -7200 # Node ID fd60a77e4cedb366640f683774df5b1362b583f9 # Parent 67062af42e7f0140d512ab766bc9489b5550a305# Parent cf5aaa798f38b04ef610489b9eab79734c642328 Merge diff -r 67062af42e7f -r fd60a77e4ced hotspot/src/cpu/sparc/vm/vm_version_sparc.cpp --- a/hotspot/src/cpu/sparc/vm/vm_version_sparc.cpp Tue Aug 21 19:25:20 2012 -0700 +++ b/hotspot/src/cpu/sparc/vm/vm_version_sparc.cpp Fri Aug 24 09:45:08 2012 +0200 @@ -106,10 +106,10 @@ if (FLAG_IS_DEFAULT(OptoLoopAlignment)) { FLAG_SET_DEFAULT(OptoLoopAlignment, 4); } - // When using CMS, we cannot use memset() in BOT updates because - // the sun4v/CMT version in libc_psr uses BIS which exposes - // "phantom zeros" to concurrent readers. See 6948537. - if (FLAG_IS_DEFAULT(UseMemSetInBOT) && UseConcMarkSweepGC) { + // When using CMS or G1, we cannot use memset() in BOT updates + // because the sun4v/CMT version in libc_psr uses BIS which + // exposes "phantom zeros" to concurrent readers. See 6948537. + if (FLAG_IS_DEFAULT(UseMemSetInBOT) && (UseConcMarkSweepGC || UseG1GC)) { FLAG_SET_DEFAULT(UseMemSetInBOT, false); } #ifdef _LP64 diff -r 67062af42e7f -r fd60a77e4ced hotspot/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.hpp --- a/hotspot/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.hpp Tue Aug 21 19:25:20 2012 -0700 +++ b/hotspot/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.hpp Fri Aug 24 09:45:08 2012 +0200 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2001, 2012, Oracle and/or its affiliates. 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 @@ -159,14 +159,30 @@ "right address out of range"); assert(left < right, "Heap addresses out of order"); size_t num_cards = pointer_delta(right, left) >> LogN_words; - memset(&_offset_array[index_for(left)], offset, num_cards); + if (UseMemSetInBOT) { + memset(&_offset_array[index_for(left)], offset, num_cards); + } else { + size_t i = index_for(left); + const size_t end = i + num_cards; + for (; i < end; i++) { + _offset_array[i] = offset; + } + } } void set_offset_array(size_t left, size_t right, u_char offset) { assert(right < _vs.committed_size(), "right address out of range"); - assert(left <= right, "indexes out of order"); + assert(left <= right, "indexes out of order"); size_t num_cards = right - left + 1; - memset(&_offset_array[left], offset, num_cards); + if (UseMemSetInBOT) { + memset(&_offset_array[left], offset, num_cards); + } else { + size_t i = left; + const size_t end = i + num_cards; + for (; i < end; i++) { + _offset_array[i] = offset; + } + } } void check_offset_array(size_t index, HeapWord* high, HeapWord* low) const { diff -r 67062af42e7f -r fd60a77e4ced hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp --- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Tue Aug 21 19:25:20 2012 -0700 +++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Fri Aug 24 09:45:08 2012 +0200 @@ -1934,6 +1934,14 @@ clear_cset_start_regions(); guarantee(_task_queues != NULL, "task_queues allocation failure."); +#ifdef SPARC + // Issue a stern warning, but allow use for experimentation and debugging. + if (VM_Version::is_sun4v() && UseMemSetInBOT) { + assert(!FLAG_IS_DEFAULT(UseMemSetInBOT), "Error"); + warning("Experimental flag -XX:+UseMemSetInBOT is known to cause instability" + " on sun4v; please understand that you are using at your own risk!"); + } +#endif } jint G1CollectedHeap::initialize() { @@ -3582,15 +3590,11 @@ DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set(); size_t buffer_size = dcqs.buffer_size(); size_t buffer_num = dcqs.completed_buffers_num(); - return buffer_size * buffer_num + extra_cards; -} - -size_t G1CollectedHeap::max_pending_card_num() { - DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set(); - size_t buffer_size = dcqs.buffer_size(); - size_t buffer_num = dcqs.completed_buffers_num(); - int thread_num = Threads::number_of_threads(); - return (buffer_num + thread_num) * buffer_size; + + // PtrQueueSet::buffer_size() and PtrQueue:size() return sizes + // in bytes - not the number of 'entries'. We need to convert + // into a number of cards. + return (buffer_size * buffer_num + extra_cards) / oopSize; } size_t G1CollectedHeap::cards_scanned() { diff -r 67062af42e7f -r fd60a77e4ced hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp --- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp Tue Aug 21 19:25:20 2012 -0700 +++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp Fri Aug 24 09:45:08 2012 +0200 @@ -1706,7 +1706,6 @@ void stop_conc_gc_threads(); size_t pending_card_num(); - size_t max_pending_card_num(); size_t cards_scanned(); protected: diff -r 67062af42e7f -r fd60a77e4ced hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp --- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp Tue Aug 21 19:25:20 2012 -0700 +++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp Fri Aug 24 09:45:08 2012 +0200 @@ -90,7 +90,6 @@ _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)), _young_cards_per_entry_ratio_seq(new TruncatedSeq(TruncatedSeqLength)), @@ -197,7 +196,6 @@ int index = MIN2(_parallel_gc_threads - 1, 7); - _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]); _young_cards_per_entry_ratio_seq->add( @@ -657,7 +655,7 @@ for (HeapRegion * r = _recorded_survivor_head; r != NULL && r != _recorded_survivor_tail->get_next_young_region(); r = r->get_next_young_region()) { - survivor_regions_evac_time += predict_region_elapsed_time_ms(r, true); + survivor_regions_evac_time += predict_region_elapsed_time_ms(r, gcs_are_young()); } return survivor_regions_evac_time; } @@ -801,9 +799,8 @@ _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_collection_set_before_gc = 0; + _collection_set_bytes_used_before = 0; _bytes_copied_during_gc = 0; YoungList* young_list = _g1->young_list(); @@ -1036,12 +1033,6 @@ // do that for any other surv rate groupsx if (update_stats) { - 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 = phase_times()->_update_rs_time / (double) _pending_cards; @@ -1126,9 +1117,9 @@ _constant_other_time_ms_seq->add(constant_other_time_ms); double survival_ratio = 0.0; - if (_bytes_in_collection_set_before_gc > 0) { + if (_collection_set_bytes_used_before > 0) { survival_ratio = (double) _bytes_copied_during_gc / - (double) _bytes_in_collection_set_before_gc; + (double) _collection_set_bytes_used_before; } _pending_cards_seq->add((double) _pending_cards); @@ -1229,18 +1220,6 @@ } double -G1CollectorPolicy::predict_base_elapsed_time_ms(size_t pending_cards) { - size_t rs_length = predict_rs_length_diff(); - size_t card_num; - if (gcs_are_young()) { - 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 @@ -1250,27 +1229,15 @@ } double -G1CollectorPolicy::predict_region_elapsed_time_ms(HeapRegion* hr, - bool young) { - size_t rs_length = hr->rem_set()->occupied(); +G1CollectorPolicy::predict_base_elapsed_time_ms(size_t pending_cards) { + size_t rs_length = predict_rs_length_diff(); size_t card_num; if (gcs_are_young()) { 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; + return predict_base_elapsed_time_ms(pending_cards, card_num); } size_t G1CollectorPolicy::predict_bytes_to_copy(HeapRegion* hr) { @@ -1286,6 +1253,35 @@ return bytes_to_copy; } +double +G1CollectorPolicy::predict_region_elapsed_time_ms(HeapRegion* hr, + bool for_young_gc) { + size_t rs_length = hr->rem_set()->occupied(); + size_t card_num; + + // Predicting the number of cards is based on which type of GC + // we're predicting for. + if (for_young_gc) { + 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); + + // The prediction of the "other" time for this region is based + // upon the region type and NOT the GC type. + if (hr->is_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; +} + void G1CollectorPolicy::init_cset_region_lengths(uint eden_cset_region_length, uint survivor_cset_region_length) { @@ -1342,22 +1338,6 @@ } } -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); -} - void G1CollectorPolicy::print_tracing_info() const { _trace_gen0_time_data.print(); _trace_gen1_time_data.print(); @@ -1696,7 +1676,7 @@ // retiring the current allocation region) or a concurrent // refine thread (RSet sampling). - double region_elapsed_time_ms = predict_region_elapsed_time_ms(hr, true); + double region_elapsed_time_ms = predict_region_elapsed_time_ms(hr, gcs_are_young()); size_t used_bytes = hr->used(); _inc_cset_recorded_rs_lengths += rs_length; _inc_cset_predicted_elapsed_time_ms += region_elapsed_time_ms; @@ -1731,7 +1711,7 @@ _inc_cset_recorded_rs_lengths_diffs += rs_lengths_diff; double old_elapsed_time_ms = hr->predicted_elapsed_time_ms(); - double new_region_elapsed_time_ms = predict_region_elapsed_time_ms(hr, true); + double new_region_elapsed_time_ms = predict_region_elapsed_time_ms(hr, gcs_are_young()); double elapsed_ms_diff = new_region_elapsed_time_ms - old_elapsed_time_ms; _inc_cset_predicted_elapsed_time_ms_diffs += elapsed_ms_diff; @@ -1854,8 +1834,7 @@ } void G1CollectorPolicy::finalize_cset(double target_pause_time_ms) { - // Set this here - in case we're not doing young collections. - double non_young_start_time_sec = os::elapsedTime(); + double young_start_time_sec = os::elapsedTime(); YoungList* young_list = _g1->young_list(); finalize_incremental_cset_building(); @@ -1869,17 +1848,14 @@ double predicted_pause_time_ms = base_time_ms; double time_remaining_ms = target_pause_time_ms - base_time_ms; - ergo_verbose3(ErgoCSetConstruction | ErgoHigh, + ergo_verbose4(ErgoCSetConstruction | ErgoHigh, "start choosing CSet", + ergo_format_size("_pending_cards") ergo_format_ms("predicted base time") ergo_format_ms("remaining time") ergo_format_ms("target pause time"), - base_time_ms, time_remaining_ms, target_pause_time_ms); + _pending_cards, base_time_ms, time_remaining_ms, target_pause_time_ms); - HeapRegion* hr; - double young_start_time_sec = os::elapsedTime(); - - _collection_set_bytes_used_before = 0; _last_gc_was_young = gcs_are_young() ? true : false; if (_last_gc_was_young) { @@ -1895,7 +1871,8 @@ uint survivor_region_length = young_list->survivor_length(); uint eden_region_length = young_list->length() - survivor_region_length; init_cset_region_lengths(eden_region_length, survivor_region_length); - hr = young_list->first_survivor_region(); + + HeapRegion* hr = young_list->first_survivor_region(); while (hr != NULL) { assert(hr->is_survivor(), "badly formed young list"); hr->set_young(); @@ -1926,8 +1903,8 @@ phase_times()->_recorded_young_cset_choice_time_ms = (young_end_time_sec - young_start_time_sec) * 1000.0; - // We are doing young collections so reset this. - non_young_start_time_sec = young_end_time_sec; + // Set the start of the non-young choice time. + double non_young_start_time_sec = young_end_time_sec; if (!gcs_are_young()) { CollectionSetChooser* cset_chooser = _collectionSetChooser; @@ -1937,6 +1914,7 @@ uint expensive_region_num = 0; bool check_time_remaining = adaptive_young_list_length(); + HeapRegion* hr = cset_chooser->peek(); while (hr != NULL) { if (old_cset_region_length() >= max_old_cset_length) { @@ -1950,7 +1928,7 @@ break; } - double predicted_time_ms = predict_region_elapsed_time_ms(hr, false); + double predicted_time_ms = predict_region_elapsed_time_ms(hr, gcs_are_young()); if (check_time_remaining) { if (predicted_time_ms > time_remaining_ms) { // Too expensive for the current CSet. @@ -2025,8 +2003,6 @@ stop_incremental_cset_building(); - count_CS_bytes_used(); - ergo_verbose5(ErgoCSetConstruction, "finish choosing CSet", ergo_format_region("eden") diff -r 67062af42e7f -r fd60a77e4ced hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp --- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp Tue Aug 21 19:25:20 2012 -0700 +++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp Fri Aug 24 09:45:08 2012 +0200 @@ -228,7 +228,6 @@ TruncatedSeq* _alloc_rate_ms_seq; double _prev_collection_pause_end_ms; - TruncatedSeq* _pending_card_diff_seq; TruncatedSeq* _rs_length_diff_seq; TruncatedSeq* _cost_per_card_ms_seq; TruncatedSeq* _young_cards_per_entry_ratio_seq; @@ -295,7 +294,6 @@ double _pause_time_target_ms; size_t _pending_cards; - size_t _max_pending_cards; public: // Accessors @@ -325,28 +323,6 @@ _max_rs_lengths = rs_lengths; } - size_t predict_pending_card_diff() { - double prediction = get_new_neg_prediction(_pending_card_diff_seq); - if (prediction < 0.00001) { - return 0; - } else { - return (size_t) prediction; - } - } - - size_t predict_pending_cards() { - size_t max_pending_card_num = _g1->max_pending_card_num(); - size_t diff = predict_pending_card_diff(); - size_t prediction; - if (diff > max_pending_card_num) { - prediction = max_pending_card_num; - } else { - prediction = max_pending_card_num - diff; - } - - return prediction; - } - size_t predict_rs_length_diff() { return (size_t) get_new_prediction(_rs_length_diff_seq); } @@ -439,7 +415,7 @@ double predict_base_elapsed_time_ms(size_t pending_cards, size_t scanned_cards); size_t predict_bytes_to_copy(HeapRegion* hr); - double predict_region_elapsed_time_ms(HeapRegion* hr, bool young); + double predict_region_elapsed_time_ms(HeapRegion* hr, bool for_young_gc); void set_recorded_rs_lengths(size_t rs_lengths); @@ -495,12 +471,6 @@ } private: - size_t _bytes_in_collection_set_before_gc; - size_t _bytes_copied_during_gc; - - // Used to count used bytes in CS. - friend class CountCSClosure; - // Statistics kept per GC stoppage, pause or full. TruncatedSeq* _recent_prev_end_times_for_all_gcs_sec; @@ -514,9 +484,13 @@ // The number of bytes in the collection set before the pause. Set from // the incrementally built collection set at the start of an evacuation - // pause. + // pause, and incremented in finalize_cset() when adding old regions + // (if any) to the collection set. size_t _collection_set_bytes_used_before; + // The number of bytes copied during the GC. + size_t _bytes_copied_during_gc; + // The associated information that is maintained while the incremental // collection set is being built with young regions. Used to populate // the recorded info for the evacuation pause. @@ -646,9 +620,6 @@ bool predict_will_fit(uint young_length, double base_time_ms, uint base_free_regions, double target_pause_time_ms); - // Count the number of bytes used in the CS. - void count_CS_bytes_used(); - public: G1CollectorPolicy(); @@ -666,10 +637,6 @@ // higher, recalculate the young list target length prediction. void revise_young_list_target_length_if_necessary(); - size_t bytes_in_collection_set() { - return _bytes_in_collection_set_before_gc; - } - // This should be called after the heap is resized. void record_new_heap_size(uint new_number_of_regions); diff -r 67062af42e7f -r fd60a77e4ced hotspot/src/share/vm/gc_implementation/g1/g1ErgoVerbose.hpp --- a/hotspot/src/share/vm/gc_implementation/g1/g1ErgoVerbose.hpp Tue Aug 21 19:25:20 2012 -0700 +++ b/hotspot/src/share/vm/gc_implementation/g1/g1ErgoVerbose.hpp Fri Aug 24 09:45:08 2012 +0200 @@ -125,6 +125,7 @@ #define ergo_format_double(_name_) ", " _name_ ": %1.2f" #define ergo_format_perc(_name_) ", " _name_ ": %1.2f %%" #define ergo_format_ms(_name_) ", " _name_ ": %1.2f ms" +#define ergo_format_size(_name_) ", " _name_ ": "SIZE_FORMAT // Double parameter format strings #define ergo_format_byte_perc(_name_) \ diff -r 67062af42e7f -r fd60a77e4ced hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp --- a/hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp Tue Aug 21 19:25:20 2012 -0700 +++ b/hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp Fri Aug 24 09:45:08 2012 +0200 @@ -287,17 +287,17 @@ "The number of times we'll force an overflow during " \ "concurrent marking") \ \ - develop(uintx, G1DefaultMinNewGenPercent, 20, \ + experimental(uintx, G1DefaultMinNewGenPercent, 20, \ "Percentage (0-100) of the heap size to use as minimum " \ "young gen size.") \ \ - develop(uintx, G1DefaultMaxNewGenPercent, 80, \ + experimental(uintx, G1DefaultMaxNewGenPercent, 80, \ "Percentage (0-100) of the heap size to use as maximum " \ "young gen size.") \ \ - develop(uintx, G1OldCSetRegionLiveThresholdPercent, 90, \ + experimental(uintx, G1OldCSetRegionLiveThresholdPercent, 90, \ "Threshold for regions to be added to the collection set. " \ - "Regions with more live bytes that this will not be collected.") \ + "Regions with more live bytes than this will not be collected.") \ \ product(uintx, G1HeapWastePercent, 5, \ "Amount of space, expressed as a percentage of the heap size, " \ @@ -306,7 +306,7 @@ product(uintx, G1MixedGCCountTarget, 4, \ "The target number of mixed GCs after a marking cycle.") \ \ - develop(uintx, G1OldCSetRegionThresholdPercent, 10, \ + experimental(uintx, G1OldCSetRegionThresholdPercent, 10, \ "An upper bound for the number of old CSet regions expressed " \ "as a percentage of the heap size.") \ \ diff -r 67062af42e7f -r fd60a77e4ced hotspot/src/share/vm/gc_implementation/g1/heapRegion.cpp --- a/hotspot/src/share/vm/gc_implementation/g1/heapRegion.cpp Tue Aug 21 19:25:20 2012 -0700 +++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegion.cpp Fri Aug 24 09:45:08 2012 +0200 @@ -384,10 +384,17 @@ } void HeapRegion::calc_gc_efficiency() { + // GC efficiency is the ratio of how much space would be + // reclaimed over how long we predict it would take to reclaim it. G1CollectedHeap* g1h = G1CollectedHeap::heap(); G1CollectorPolicy* g1p = g1h->g1_policy(); - _gc_efficiency = (double) reclaimable_bytes() / - g1p->predict_region_elapsed_time_ms(this, false); + + // Retrieve a prediction of the elapsed time for this region for + // a mixed gc because the region will only be evacuated during a + // mixed gc. + double region_elapsed_time_ms = + g1p->predict_region_elapsed_time_ms(this, false /* for_young_gc */); + _gc_efficiency = (double) reclaimable_bytes() / region_elapsed_time_ms; } void HeapRegion::set_startsHumongous(HeapWord* new_top, HeapWord* new_end) {