1 /* 2 * Copyright (c) 2019, 2021, 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/shenandoah/heuristics/shenandoahPassiveHeuristics.hpp" 27 #include "gc/shenandoah/mode/shenandoahPassiveMode.hpp" 28 #include "gc/shenandoah/shenandoahHeap.inline.hpp" 29 #include "logging/log.hpp" 30 #include "logging/logTag.hpp" 31 #include "runtime/globals_extension.hpp" 32 #include "runtime/java.hpp" 33 34 void ShenandoahPassiveMode::initialize_flags() const { 35 // Do not allow concurrent cycles. 36 FLAG_SET_DEFAULT(ExplicitGCInvokesConcurrent, false); 37 FLAG_SET_DEFAULT(ShenandoahImplicitGCInvokesConcurrent, false); 38 39 // Passive runs with max speed for allocation, because GC is always STW 40 SHENANDOAH_ERGO_DISABLE_FLAG(ShenandoahPacing); 41 42 // No need for evacuation reserve with Full GC, only for Degenerated GC. 43 if (!ShenandoahDegeneratedGC) { 44 SHENANDOAH_ERGO_OVERRIDE_DEFAULT(ShenandoahEvacReserve, 0); 45 } 46 47 // Disable known barriers by default. 48 SHENANDOAH_ERGO_DISABLE_FLAG(ShenandoahLoadRefBarrier); 49 SHENANDOAH_ERGO_DISABLE_FLAG(ShenandoahSATBBarrier); 50 SHENANDOAH_ERGO_DISABLE_FLAG(ShenandoahCASBarrier); 51 SHENANDOAH_ERGO_DISABLE_FLAG(ShenandoahCloneBarrier); 52 SHENANDOAH_ERGO_DISABLE_FLAG(ShenandoahStackWatermarkBarrier); 53 54 // Final configuration checks 55 // No barriers are required to run. 56 } 57 ShenandoahHeuristics* ShenandoahPassiveMode::initialize_heuristics() const { 58 if (ShenandoahGCHeuristics == nullptr) { 59 vm_exit_during_initialization("Unknown -XX:ShenandoahGCHeuristics option (null)"); 60 } 61 return new ShenandoahPassiveHeuristics(ShenandoahHeap::heap()); 62 } --- EOF ---