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 "precompiled.hpp" 26 #include "gc/g1/g1YoungGenSizer.hpp" 27 #include "gc/g1/heapRegion.hpp" 28 29 G1YoungGenSizer::G1YoungGenSizer() : _sizer_kind(SizerDefaults), _adaptive_size(true), 30 _min_desired_young_length(0), _max_desired_young_length(0) { 31 if (FLAG_IS_CMDLINE(NewRatio)) { 32 if (FLAG_IS_CMDLINE(NewSize) || FLAG_IS_CMDLINE(MaxNewSize)) { 33 log_warning(gc, ergo)("-XX:NewSize and -XX:MaxNewSize override -XX:NewRatio"); 34 } else { 35 _sizer_kind = SizerNewRatio; 36 _adaptive_size = false; 37 return; 38 } 39 } 40 41 if (NewSize > MaxNewSize) { 42 if (FLAG_IS_CMDLINE(MaxNewSize)) { 43 log_warning(gc, ergo)("NewSize (" SIZE_FORMAT "k) is greater than the MaxNewSize (" SIZE_FORMAT "k). " 44 "A new max generation size of " SIZE_FORMAT "k will be used.", 45 NewSize/K, MaxNewSize/K, NewSize/K); 46 } 47 MaxNewSize = NewSize; 48 } 49 50 if (FLAG_IS_CMDLINE(NewSize)) { 51 _min_desired_young_length = MAX2((uint) (NewSize / HeapRegion::GrainBytes), 52 1U); 53 if (FLAG_IS_CMDLINE(MaxNewSize)) { 54 _max_desired_young_length = 55 MAX2((uint) (MaxNewSize / HeapRegion::GrainBytes), 56 1U); 57 _sizer_kind = SizerMaxAndNewSize; 58 _adaptive_size = _min_desired_young_length == _max_desired_young_length; 59 } else { 60 _sizer_kind = SizerNewSizeOnly; 61 } 62 } else if (FLAG_IS_CMDLINE(MaxNewSize)) { 63 _max_desired_young_length = 64 MAX2((uint) (MaxNewSize / HeapRegion::GrainBytes), 65 1U); 66 _sizer_kind = SizerMaxNewSizeOnly; 67 } 68 } 69 70 uint G1YoungGenSizer::calculate_default_min_length(uint new_number_of_heap_regions) { 71 uint default_value = (new_number_of_heap_regions * G1NewSizePercent) / 100; 72 return MAX2(1U, default_value); 73 } 74 75 uint G1YoungGenSizer::calculate_default_max_length(uint new_number_of_heap_regions) { 76 uint default_value = (new_number_of_heap_regions * G1MaxNewSizePercent) / 100; 77 return MAX2(1U, default_value); 78 } 79 80 void G1YoungGenSizer::recalculate_min_max_young_length(uint number_of_heap_regions, uint* min_young_length, uint* max_young_length) { 81 assert(number_of_heap_regions > 0, "Heap must be initialized"); 82 83 switch (_sizer_kind) { 84 case SizerDefaults: 85 *min_young_length = calculate_default_min_length(number_of_heap_regions); 86 *max_young_length = calculate_default_max_length(number_of_heap_regions); 87 break; 88 case SizerNewSizeOnly: 89 *max_young_length = calculate_default_max_length(number_of_heap_regions); 90 *max_young_length = MAX2(*min_young_length, *max_young_length); 91 break; 92 case SizerMaxNewSizeOnly: 93 *min_young_length = calculate_default_min_length(number_of_heap_regions); 94 *min_young_length = MIN2(*min_young_length, *max_young_length); 95 break; 96 case SizerMaxAndNewSize: 97 // Do nothing. Values set on the command line, don't update them at runtime. 98 break; 99 case SizerNewRatio: 100 *min_young_length = number_of_heap_regions / (NewRatio + 1); 101 *max_young_length = *min_young_length; 102 break; 103 default: 104 ShouldNotReachHere(); 105 } 106 107 assert(*min_young_length <= *max_young_length, "Invalid min/max young gen size values"); 108 } 109 110 uint G1YoungGenSizer::max_young_length(uint number_of_heap_regions) { 111 // We need to pass the desired values because recalculation may not update these 112 // values in some cases. 113 uint temp = _min_desired_young_length; 114 uint result = _max_desired_young_length; 115 recalculate_min_max_young_length(number_of_heap_regions, &temp, &result); 116 return result; 117 } 118 119 void G1YoungGenSizer::heap_size_changed(uint new_number_of_heap_regions) { 120 recalculate_min_max_young_length(new_number_of_heap_regions, &_min_desired_young_length, 121 &_max_desired_young_length); 122 }