1 /* 2 * Copyright (c) 2018, 2019, Red Hat, Inc. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 27 #include "gc/shenandoah/heuristics/shenandoahStaticHeuristics.hpp" 28 #include "gc/shenandoah/shenandoahCollectionSet.hpp" 29 #include "gc/shenandoah/shenandoahFreeSet.hpp" 30 #include "gc/shenandoah/shenandoahHeapRegion.hpp" 31 #include "logging/log.hpp" 32 #include "logging/logTag.hpp" 33 34 ShenandoahStaticHeuristics::ShenandoahStaticHeuristics() : ShenandoahHeuristics() { 35 // Static heuristics may degrade to continuous if live data is larger 36 // than free threshold. ShenandoahAllocationThreshold is supposed to break this, 37 // but it only works if it is non-zero. 38 SHENANDOAH_ERGO_OVERRIDE_DEFAULT(ShenandoahAllocationThreshold, 1); 39 40 SHENANDOAH_ERGO_ENABLE_FLAG(ExplicitGCInvokesConcurrent); 41 SHENANDOAH_ERGO_ENABLE_FLAG(ShenandoahImplicitGCInvokesConcurrent); 42 43 // Final configuration checks 44 SHENANDOAH_CHECK_FLAG_SET(ShenandoahLoadRefBarrier); 45 SHENANDOAH_CHECK_FLAG_SET(ShenandoahSATBBarrier); 46 SHENANDOAH_CHECK_FLAG_SET(ShenandoahKeepAliveBarrier); 47 SHENANDOAH_CHECK_FLAG_SET(ShenandoahCASBarrier); 48 SHENANDOAH_CHECK_FLAG_SET(ShenandoahCloneBarrier); 49 } 50 51 ShenandoahStaticHeuristics::~ShenandoahStaticHeuristics() {} 52 53 bool ShenandoahStaticHeuristics::should_start_gc() const { 54 ShenandoahHeap* heap = ShenandoahHeap::heap(); 55 56 size_t capacity = heap->max_capacity(); 57 size_t available = heap->free_set()->available(); 58 size_t threshold_available = capacity / 100 * ShenandoahFreeThreshold; 59 60 if (available < threshold_available) { 61 log_info(gc)("Trigger: Free (" SIZE_FORMAT "%s) is below free threshold (" SIZE_FORMAT "%s)", 62 byte_size_in_proper_unit(available), proper_unit_for_byte_size(available), 63 byte_size_in_proper_unit(threshold_available), proper_unit_for_byte_size(threshold_available)); 64 return true; 65 } 66 return ShenandoahHeuristics::should_start_gc(); 67 } 68 69 void ShenandoahStaticHeuristics::choose_collection_set_from_regiondata(ShenandoahCollectionSet* cset, 70 RegionData* data, size_t size, 71 size_t free) { 72 size_t threshold = ShenandoahHeapRegion::region_size_bytes() * ShenandoahGarbageThreshold / 100; 73 74 for (size_t idx = 0; idx < size; idx++) { 75 ShenandoahHeapRegion* r = data[idx]._region; 76 if (r->garbage() > threshold) { 77 cset->add_region(r); 78 } 79 } 80 } 81 82 const char* ShenandoahStaticHeuristics::name() { 83 return "static"; 84 } 85 86 bool ShenandoahStaticHeuristics::is_diagnostic() { 87 return false; 88 } 89 90 bool ShenandoahStaticHeuristics::is_experimental() { 91 return false; 92 }