1 /* 2 * Copyright (c) 2016, Oracle and/or its affiliates. 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 "gc/parallel/parallelGC.hpp" 26 #include "gc/parallel/parallelGCServicabilitySupport.hpp" 27 #include "gc/parallel/generationSizer.hpp" 28 #include "gc/parallel/parallelScavengeHeap.hpp" 29 #include "utilities/defaultStream.hpp" 30 31 CollectedHeap* ParallelGC::create_heap() { 32 GenerationSizer* policy = new GenerationSizer(); 33 policy->initialize_all(); 34 return new ParallelScavengeHeap(policy); 35 } 36 37 void ParallelGC::initialize_flags() { 38 assert(UseParallelGC || UseParallelOldGC, "Error"); 39 // Enable ParallelOld unless it was explicitly disabled (cmd line or rc file). 40 if (FLAG_IS_DEFAULT(UseParallelOldGC)) { 41 FLAG_SET_DEFAULT(UseParallelOldGC, true); 42 } 43 FLAG_SET_DEFAULT(UseParallelGC, true); 44 45 // If no heap maximum was requested explicitly, use some reasonable fraction 46 // of the physical memory, up to a maximum of 1GB. 47 FLAG_SET_DEFAULT(ParallelGCThreads, 48 Abstract_VM_Version::parallel_worker_threads()); 49 if (ParallelGCThreads == 0) { 50 jio_fprintf(defaultStream::error_stream(), 51 "The Parallel GC can not be combined with -XX:ParallelGCThreads=0\n"); 52 vm_exit(1); 53 } 54 55 if (UseAdaptiveSizePolicy) { 56 // We don't want to limit adaptive heap sizing's freedom to adjust the heap 57 // unless the user actually sets these flags. 58 if (FLAG_IS_DEFAULT(MinHeapFreeRatio)) { 59 FLAG_SET_DEFAULT(MinHeapFreeRatio, 0); 60 } 61 if (FLAG_IS_DEFAULT(MaxHeapFreeRatio)) { 62 FLAG_SET_DEFAULT(MaxHeapFreeRatio, 100); 63 } 64 } 65 66 // If InitialSurvivorRatio or MinSurvivorRatio were not specified, but the 67 // SurvivorRatio has been set, reset their default values to SurvivorRatio + 68 // 2. By doing this we make SurvivorRatio also work for Parallel Scavenger. 69 // See CR 6362902 for details. 70 if (!FLAG_IS_DEFAULT(SurvivorRatio)) { 71 if (FLAG_IS_DEFAULT(InitialSurvivorRatio)) { 72 FLAG_SET_DEFAULT(InitialSurvivorRatio, SurvivorRatio + 2); 73 } 74 if (FLAG_IS_DEFAULT(MinSurvivorRatio)) { 75 FLAG_SET_DEFAULT(MinSurvivorRatio, SurvivorRatio + 2); 76 } 77 } 78 79 if (UseParallelOldGC) { 80 // Par compact uses lower default values since they are treated as 81 // minimums. These are different defaults because of the different 82 // interpretation and are not ergonomically set. 83 if (FLAG_IS_DEFAULT(MarkSweepDeadRatio)) { 84 FLAG_SET_DEFAULT(MarkSweepDeadRatio, 1); 85 } 86 } 87 } 88 89 size_t ParallelGC::conservative_max_heap_alignment() { 90 return CollectorPolicy::compute_heap_alignment(); 91 } 92 93 GCServicabilitySupport* ParallelGC::create_servicability_support() { 94 return new ParallelGCServicabilitySupport(); 95 }