1 /* 2 * Copyright (c) 2001, 2015, 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/parallel/generationSizer.hpp" 27 #include "gc/shared/collectorPolicy.hpp" 28 #include "runtime/globals_extension.hpp" 29 #include "utilities/align.hpp" 30 #include "utilities/globalDefinitions.hpp" 31 32 void GenerationSizer::initialize_alignments() { 33 _space_alignment = _gen_alignment = default_gen_alignment(); 34 _heap_alignment = compute_heap_alignment(); 35 } 36 37 void GenerationSizer::initialize_flags() { 38 // Do basic sizing work 39 GenCollectorPolicy::initialize_flags(); 40 41 // The survivor ratio's are calculated "raw", unlike the 42 // default gc, which adds 2 to the ratio value. We need to 43 // make sure the values are valid before using them. 44 if (MinSurvivorRatio < 3) { 45 FLAG_SET_ERGO(uintx, MinSurvivorRatio, 3); 46 } 47 48 if (InitialSurvivorRatio < 3) { 49 FLAG_SET_ERGO(uintx, InitialSurvivorRatio, 3); 50 } 51 } 52 53 void GenerationSizer::initialize_size_info() { 54 const size_t max_page_sz = os::page_size_for_region_aligned(_max_heap_byte_size, 8); 55 const size_t min_pages = 4; // 1 for eden + 1 for each survivor + 1 for old 56 const size_t min_page_sz = os::page_size_for_region_aligned(_min_heap_byte_size, min_pages); 57 const size_t page_sz = MIN2(max_page_sz, min_page_sz); 58 59 // Can a page size be something else than a power of two? 60 assert(is_power_of_2((intptr_t)page_sz), "must be a power of 2"); 61 size_t new_alignment = align_up(page_sz, _gen_alignment); 62 if (new_alignment != _gen_alignment) { 63 _gen_alignment = new_alignment; 64 _space_alignment = new_alignment; 65 // Redo everything from the start 66 initialize_flags(); 67 } 68 GenCollectorPolicy::initialize_size_info(); 69 }