1 /* 2 * Copyright (c) 2018, 2019, Red Hat, Inc. All rights reserved. 3 * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 * 24 */ 25 26 #include "precompiled.hpp" 27 28 #include "gc/shenandoah/heuristics/shenandoahStaticHeuristics.hpp" 29 #include "gc/shenandoah/shenandoahCollectionSet.hpp" 30 #include "gc/shenandoah/shenandoahFreeSet.hpp" 31 #include "gc/shenandoah/shenandoahHeap.inline.hpp" 32 #include "gc/shenandoah/shenandoahHeapRegion.inline.hpp" 33 #include "logging/log.hpp" 34 #include "logging/logTag.hpp" 35 36 ShenandoahStaticHeuristics::ShenandoahStaticHeuristics(ShenandoahSpaceInfo* space_info) : 37 ShenandoahHeuristics(space_info) { 38 SHENANDOAH_ERGO_ENABLE_FLAG(ExplicitGCInvokesConcurrent); 39 SHENANDOAH_ERGO_ENABLE_FLAG(ShenandoahImplicitGCInvokesConcurrent); 40 } 41 42 ShenandoahStaticHeuristics::~ShenandoahStaticHeuristics() {} 43 44 bool ShenandoahStaticHeuristics::should_start_gc() { 45 size_t max_capacity = _space_info->max_capacity(); 46 size_t capacity = _space_info->soft_max_capacity(); 47 size_t available = _space_info->available(); 48 49 // Make sure the code below treats available without the soft tail. 50 size_t soft_tail = max_capacity - capacity; 51 available = (available > soft_tail) ? (available - soft_tail) : 0; 52 53 size_t threshold_available = capacity / 100 * ShenandoahMinFreeThreshold; 54 55 if (available < threshold_available) { 56 log_info(gc)("Trigger: Free (" SIZE_FORMAT "%s) is below minimum threshold (" SIZE_FORMAT "%s)", 57 byte_size_in_proper_unit(available), proper_unit_for_byte_size(available), 58 byte_size_in_proper_unit(threshold_available), proper_unit_for_byte_size(threshold_available)); 59 return true; 60 } 61 return ShenandoahHeuristics::should_start_gc(); 62 } 63 64 void ShenandoahStaticHeuristics::choose_collection_set_from_regiondata(ShenandoahCollectionSet* cset, 65 RegionData* data, size_t size, 66 size_t free) { 67 size_t threshold = ShenandoahHeapRegion::region_size_bytes() * ShenandoahGarbageThreshold / 100; 68 69 for (size_t idx = 0; idx < size; idx++) { 70 ShenandoahHeapRegion* r = data[idx]._region; 71 if (r->garbage() > threshold) { 72 cset->add_region(r); 73 } 74 } 75 }