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