1 /* 2 * Copyright (c) 2001, 2013, 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 #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_GENERATIONSIZER_HPP 26 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_GENERATIONSIZER_HPP 27 28 #include "memory/collectorPolicy.hpp" 29 30 // There is a nice batch of tested generation sizing code in 31 // TwoGenerationCollectorPolicy. Lets reuse it! 32 33 class GenerationSizer : public TwoGenerationCollectorPolicy { 34 private: 35 36 void trace_gen_sizes(const char* const str) { 37 if (TracePageSizes) { 38 tty->print_cr("%s: " SIZE_FORMAT "," SIZE_FORMAT " " 39 SIZE_FORMAT "," SIZE_FORMAT " " 40 SIZE_FORMAT, 41 str, 42 _min_gen1_size / K, _max_gen1_size / K, 43 _min_gen0_size / K, _max_gen0_size / K, 44 _max_heap_byte_size / K); 45 } 46 } 47 48 public: 49 GenerationSizer() { 50 initialize_all(); 51 } 52 53 void initialize_flags() { 54 // Do basic sizing work 55 TwoGenerationCollectorPolicy::initialize_flags(); 56 57 assert(UseSerialGC || 58 !FLAG_IS_DEFAULT(ParallelGCThreads) || 59 (ParallelGCThreads > 0), 60 "ParallelGCThreads should be set before flag initialization"); 61 62 // The survivor ratio's are calculated "raw", unlike the 63 // default gc, which adds 2 to the ratio value. We need to 64 // make sure the values are valid before using them. 65 if (MinSurvivorRatio < 3) { 66 MinSurvivorRatio = 3; 67 } 68 69 if (InitialSurvivorRatio < 3) { 70 InitialSurvivorRatio = 3; 71 } 72 } 73 74 void initialize_size_info() { 75 TwoGenerationCollectorPolicy::initialize_size_info(); 76 77 trace_gen_sizes("ps heap raw"); 78 const size_t page_sz = os::page_size_for_region(_min_heap_byte_size, 79 _max_heap_byte_size, 80 8); 81 82 // Can a page size be something else than a power of two? 83 assert(is_power_of_2((intptr_t)page_sz), "must be a power of 2"); 84 _min_alignment = round_to(page_sz, intra_heap_alignment()); 85 86 // Update sizes to reflect the selected page size. 87 _min_gen0_size = align_size_up(_min_gen0_size, _min_alignment); 88 _initial_gen0_size = MAX2(align_size_up_(_initial_gen0_size, _min_alignment), _min_gen0_size); 89 _max_gen0_size = align_size_up(_max_gen0_size, _min_alignment); 90 91 // Align old gen size down to preserve specified heap size. Adjust all other values. 92 _max_gen1_size = max_heap_byte_size() - _max_gen0_size; 93 _min_gen1_size = MIN2(align_size_up_(_min_gen1_size, _min_alignment), _max_gen1_size); 94 _initial_gen1_size = MIN2(align_size_up_(_initial_gen1_size, _min_alignment), _max_gen1_size); 95 96 trace_gen_sizes("ps heap rnd"); 97 } 98 }; 99 100 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_GENERATIONSIZER_HPP