1 /* 2 * Copyright (c) 2018, 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 "precompiled.hpp" 26 #include "gc/g1/g1HeterogeneousCollectorPolicy.hpp" 27 #include "logging/log.hpp" 28 #include "runtime/globals_extension.hpp" 29 #include "runtime/os.hpp" 30 #include "utilities/formatBuffer.hpp" 31 32 const double G1HeterogeneousCollectorPolicy::MaxRamFractionForYoung = 0.8; 33 size_t G1HeterogeneousCollectorPolicy::MaxMemoryForYoung; 34 35 static size_t calculate_reasonable_max_memory_for_young(FormatBuffer<100> &calc_str, double max_ram_fraction_for_young) { 36 julong phys_mem; 37 // If MaxRam is specified, we use that as maximum physical memory available. 38 if (FLAG_IS_DEFAULT(MaxRAM)) { 39 phys_mem = os::physical_memory(); 40 calc_str.append("Physical_Memory"); 41 } else { 42 phys_mem = (julong)MaxRAM; 43 calc_str.append("MaxRAM"); 44 } 45 46 julong reasonable_max = phys_mem; 47 48 // If either MaxRAMFraction or MaxRAMPercentage is specified, we use them to calculate 49 // reasonable max size of young generation. 50 if (!FLAG_IS_DEFAULT(MaxRAMFraction)) { 51 reasonable_max = (julong)(phys_mem / MaxRAMFraction); 52 calc_str.append(" / MaxRAMFraction"); 53 } else if (!FLAG_IS_DEFAULT(MaxRAMPercentage)) { 54 reasonable_max = (julong)((phys_mem * MaxRAMPercentage) / 100); 55 calc_str.append(" * MaxRAMPercentage / 100"); 56 } else { 57 // We use our own fraction to calculate max size of young generation. 58 reasonable_max = phys_mem * max_ram_fraction_for_young; 59 calc_str.append(" * %0.2f", max_ram_fraction_for_young); 60 } 61 62 return (size_t)reasonable_max; 63 } 64 65 void G1HeterogeneousCollectorPolicy::initialize_flags() { 66 67 FormatBuffer<100> calc_str(""); 68 69 MaxMemoryForYoung = calculate_reasonable_max_memory_for_young(calc_str, MaxRamFractionForYoung); 70 71 if (MaxNewSize > MaxMemoryForYoung) { 72 if (FLAG_IS_CMDLINE(MaxNewSize)) { 73 log_warning(gc, ergo)("Setting MaxNewSize to " SIZE_FORMAT " based on dram available (calculation = align(%s))", 74 MaxMemoryForYoung, calc_str.buffer()); 75 } else { 76 log_info(gc, ergo)("Setting MaxNewSize to " SIZE_FORMAT " based on dram available (calculation = align(%s)). " 77 "Dram usage can be lowered by setting MaxNewSize to a lower value", MaxMemoryForYoung, calc_str.buffer()); 78 } 79 MaxNewSize = MaxMemoryForYoung; 80 } 81 if (NewSize > MaxMemoryForYoung) { 82 if (FLAG_IS_CMDLINE(NewSize)) { 83 log_warning(gc, ergo)("Setting NewSize to " SIZE_FORMAT " based on dram available (calculation = align(%s))", 84 MaxMemoryForYoung, calc_str.buffer()); 85 } 86 NewSize = MaxMemoryForYoung; 87 } 88 89 // After setting new size flags, call base class initialize_flags() 90 G1CollectorPolicy::initialize_flags(); 91 } 92 93 size_t G1HeterogeneousCollectorPolicy::reasonable_max_memory_for_young() { 94 return MaxMemoryForYoung; 95 } 96 97 size_t G1HeterogeneousCollectorPolicy::heap_reserved_size_bytes() const { 98 return 2 * _max_heap_byte_size; 99 } 100 101 bool G1HeterogeneousCollectorPolicy::is_hetero_heap() const { 102 return true; 103 }