1 /* 2 * Copyright (c) 2017, 2018, 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 #include "gc/epsilon/epsilonArguments.hpp" 27 #include "gc/epsilon/epsilonHeap.hpp" 28 #include "gc/shared/gcArguments.hpp" 29 #include "runtime/globals.hpp" 30 #include "runtime/globals_extension.hpp" 31 #include "runtime/vm_version.hpp" 32 #include "utilities/macros.hpp" 33 34 size_t EpsilonArguments::conservative_max_heap_alignment() { 35 return UseLargePages ? os::large_page_size() : os::vm_page_size(); 36 } 37 38 void EpsilonArguments::initialize() { 39 GCArguments::initialize(); 40 41 assert(UseEpsilonGC, "Sanity"); 42 43 // Forcefully exit when OOME is detected. Nothing we can do at that point. 44 if (FLAG_IS_DEFAULT(ExitOnOutOfMemoryError)) { 45 FLAG_SET_DEFAULT(ExitOnOutOfMemoryError, true); 46 } 47 48 // Warn users that non-resizable heap might be better for some configurations. 49 // We are not adjusting the heap size by ourselves, because it affects startup time. 50 if (InitialHeapSize != MaxHeapSize) { 51 log_warning(gc)("Consider setting -Xms equal to -Xmx to avoid resizing hiccups"); 52 } 53 54 // Warn users that AlwaysPreTouch might be better for some configurations. 55 // We are not turning this on by ourselves, because it affects startup time. 56 if (FLAG_IS_DEFAULT(AlwaysPreTouch) && !AlwaysPreTouch) { 57 log_warning(gc)("Consider enabling -XX:+AlwaysPreTouch to avoid memory commit hiccups"); 58 } 59 60 if (EpsilonMaxTLABSize < MinTLABSize) { 61 log_warning(gc)("EpsilonMaxTLABSize < MinTLABSize, adjusting it to " SIZE_FORMAT, MinTLABSize); 62 EpsilonMaxTLABSize = MinTLABSize; 63 } 64 65 if (!EpsilonElasticTLAB && EpsilonElasticTLABDecay) { 66 log_warning(gc)("Disabling EpsilonElasticTLABDecay because EpsilonElasticTLAB is disabled"); 67 FLAG_SET_DEFAULT(EpsilonElasticTLABDecay, false); 68 } 69 70 #ifdef COMPILER2 71 // Enable loop strip mining: there are still non-GC safepoints, no need to make it worse 72 if (FLAG_IS_DEFAULT(UseCountedLoopSafepoints)) { 73 FLAG_SET_DEFAULT(UseCountedLoopSafepoints, true); 74 if (FLAG_IS_DEFAULT(LoopStripMiningIter)) { 75 FLAG_SET_DEFAULT(LoopStripMiningIter, 1000); 76 } 77 } 78 #endif 79 } 80 81 void EpsilonArguments::initialize_alignments() { 82 size_t page_size = UseLargePages ? os::large_page_size() : os::vm_page_size(); 83 size_t align = MAX2((size_t)os::vm_allocation_granularity(), page_size); 84 SpaceAlignment = align; 85 HeapAlignment = align; 86 } 87 88 CollectedHeap* EpsilonArguments::create_heap() { 89 return new EpsilonHeap(); 90 }