diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/hotspot/share/gc/g1/g1IHOPControl.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/hotspot/share/gc/g1/g1IHOPControl.cpp Tue Sep 12 19:03:39 2017 +0200 @@ -0,0 +1,185 @@ +/* + * Copyright (c) 2015, 2016, 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 + * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#include "precompiled.hpp" +#include "gc/g1/g1CollectedHeap.inline.hpp" +#include "gc/g1/g1IHOPControl.hpp" +#include "gc/g1/g1Predictions.hpp" +#include "gc/shared/gcTrace.hpp" +#include "logging/log.hpp" + +G1IHOPControl::G1IHOPControl(double initial_ihop_percent) : + _initial_ihop_percent(initial_ihop_percent), + _target_occupancy(0), + _last_allocated_bytes(0), + _last_allocation_time_s(0.0) +{ + assert(_initial_ihop_percent >= 0.0 && _initial_ihop_percent <= 100.0, "Initial IHOP value must be between 0 and 100 but is %.3f", initial_ihop_percent); +} + +void G1IHOPControl::update_target_occupancy(size_t new_target_occupancy) { + log_debug(gc, ihop)("Target occupancy update: old: " SIZE_FORMAT "B, new: " SIZE_FORMAT "B", + _target_occupancy, new_target_occupancy); + _target_occupancy = new_target_occupancy; +} + +void G1IHOPControl::update_allocation_info(double allocation_time_s, size_t allocated_bytes, size_t additional_buffer_size) { + assert(allocation_time_s >= 0.0, "Allocation time must be positive but is %.3f", allocation_time_s); + + _last_allocation_time_s = allocation_time_s; + _last_allocated_bytes = allocated_bytes; +} + +void G1IHOPControl::print() { + assert(_target_occupancy > 0, "Target occupancy still not updated yet."); + size_t cur_conc_mark_start_threshold = get_conc_mark_start_threshold(); + log_debug(gc, ihop)("Basic information (value update), threshold: " SIZE_FORMAT "B (%1.2f), target occupancy: " SIZE_FORMAT "B, current occupancy: " SIZE_FORMAT "B, " + "recent allocation size: " SIZE_FORMAT "B, recent allocation duration: %1.2fms, recent old gen allocation rate: %1.2fB/s, recent marking phase length: %1.2fms", + cur_conc_mark_start_threshold, + cur_conc_mark_start_threshold * 100.0 / _target_occupancy, + _target_occupancy, + G1CollectedHeap::heap()->used(), + _last_allocated_bytes, + _last_allocation_time_s * 1000.0, + _last_allocation_time_s > 0.0 ? _last_allocated_bytes / _last_allocation_time_s : 0.0, + last_marking_length_s() * 1000.0); +} + +void G1IHOPControl::send_trace_event(G1NewTracer* tracer) { + assert(_target_occupancy > 0, "Target occupancy still not updated yet."); + tracer->report_basic_ihop_statistics(get_conc_mark_start_threshold(), + _target_occupancy, + G1CollectedHeap::heap()->used(), + _last_allocated_bytes, + _last_allocation_time_s, + last_marking_length_s()); +} + +G1StaticIHOPControl::G1StaticIHOPControl(double ihop_percent) : + G1IHOPControl(ihop_percent), + _last_marking_length_s(0.0) { +} + +G1AdaptiveIHOPControl::G1AdaptiveIHOPControl(double ihop_percent, + G1Predictions const* predictor, + size_t heap_reserve_percent, + size_t heap_waste_percent) : + G1IHOPControl(ihop_percent), + _predictor(predictor), + _marking_times_s(10, 0.95), + _allocation_rate_s(10, 0.95), + _last_unrestrained_young_size(0), + _heap_reserve_percent(heap_reserve_percent), + _heap_waste_percent(heap_waste_percent) +{ +} + +size_t G1AdaptiveIHOPControl::actual_target_threshold() const { + guarantee(_target_occupancy > 0, "Target occupancy still not updated yet."); + // The actual target threshold takes the heap reserve and the expected waste in + // free space into account. + // _heap_reserve is that part of the total heap capacity that is reserved for + // eventual promotion failure. + // _heap_waste is the amount of space will never be reclaimed in any + // heap, so can not be used for allocation during marking and must always be + // considered. + + double safe_total_heap_percentage = MIN2((double)(_heap_reserve_percent + _heap_waste_percent), 100.0); + + return (size_t)MIN2( + G1CollectedHeap::heap()->max_capacity() * (100.0 - safe_total_heap_percentage) / 100.0, + _target_occupancy * (100.0 - _heap_waste_percent) / 100.0 + ); +} + +bool G1AdaptiveIHOPControl::have_enough_data_for_prediction() const { + return ((size_t)_marking_times_s.num() >= G1AdaptiveIHOPNumInitialSamples) && + ((size_t)_allocation_rate_s.num() >= G1AdaptiveIHOPNumInitialSamples); +} + +size_t G1AdaptiveIHOPControl::get_conc_mark_start_threshold() { + if (have_enough_data_for_prediction()) { + double pred_marking_time = _predictor->get_new_prediction(&_marking_times_s); + double pred_promotion_rate = _predictor->get_new_prediction(&_allocation_rate_s); + size_t pred_promotion_size = (size_t)(pred_marking_time * pred_promotion_rate); + + size_t predicted_needed_bytes_during_marking = + pred_promotion_size + + // In reality we would need the maximum size of the young gen during + // marking. This is a conservative estimate. + _last_unrestrained_young_size; + + size_t internal_threshold = actual_target_threshold(); + size_t predicted_initiating_threshold = predicted_needed_bytes_during_marking < internal_threshold ? + internal_threshold - predicted_needed_bytes_during_marking : + 0; + return predicted_initiating_threshold; + } else { + // Use the initial value. + return (size_t)(_initial_ihop_percent * _target_occupancy / 100.0); + } +} + +void G1AdaptiveIHOPControl::update_allocation_info(double allocation_time_s, + size_t allocated_bytes, + size_t additional_buffer_size) { + G1IHOPControl::update_allocation_info(allocation_time_s, allocated_bytes, additional_buffer_size); + + double allocation_rate = (double) allocated_bytes / allocation_time_s; + _allocation_rate_s.add(allocation_rate); + + _last_unrestrained_young_size = additional_buffer_size; +} + +void G1AdaptiveIHOPControl::update_marking_length(double marking_length_s) { + assert(marking_length_s >= 0.0, "Marking length must be larger than zero but is %.3f", marking_length_s); + _marking_times_s.add(marking_length_s); +} + +void G1AdaptiveIHOPControl::print() { + G1IHOPControl::print(); + size_t actual_target = actual_target_threshold(); + log_debug(gc, ihop)("Adaptive IHOP information (value update), threshold: " SIZE_FORMAT "B (%1.2f), internal target occupancy: " SIZE_FORMAT "B, " + "occupancy: " SIZE_FORMAT "B, additional buffer size: " SIZE_FORMAT "B, predicted old gen allocation rate: %1.2fB/s, " + "predicted marking phase length: %1.2fms, prediction active: %s", + get_conc_mark_start_threshold(), + percent_of(get_conc_mark_start_threshold(), actual_target), + actual_target, + G1CollectedHeap::heap()->used(), + _last_unrestrained_young_size, + _predictor->get_new_prediction(&_allocation_rate_s), + _predictor->get_new_prediction(&_marking_times_s) * 1000.0, + have_enough_data_for_prediction() ? "true" : "false"); +} + +void G1AdaptiveIHOPControl::send_trace_event(G1NewTracer* tracer) { + G1IHOPControl::send_trace_event(tracer); + tracer->report_adaptive_ihop_statistics(get_conc_mark_start_threshold(), + actual_target_threshold(), + G1CollectedHeap::heap()->used(), + _last_unrestrained_young_size, + _predictor->get_new_prediction(&_allocation_rate_s), + _predictor->get_new_prediction(&_marking_times_s), + have_enough_data_for_prediction()); +}