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/shared/cardTableRS.hpp" 27 #include "gc/shared/gcSettings.hpp" 28 #include "runtime/arguments.hpp" 29 #include "runtime/os.hpp" 30 #include "utilities/globalDefinitions.hpp" 31 32 size_t compute_heap_alignment() { 33 // The card marking array and the offset arrays for old generations are 34 // committed in os pages as well. Make sure they are entirely full (to 35 // avoid partial page problems), e.g. if 512 bytes heap corresponds to 1 36 // byte entry and the os page size is 4096, the maximum heap size should 37 // be 512*4096 = 2MB aligned. 38 39 size_t alignment = CardTableRS::ct_max_alignment_constraint(); 40 41 if (UseLargePages) { 42 // In presence of large pages we have to make sure that our 43 // alignment is large page aware. 44 alignment = lcm(os::large_page_size(), alignment); 45 } 46 47 return alignment; 48 } 49 50 void GCSettings::initialize() { 51 _initial_heap_byte_size = InitialHeapSize; 52 _max_heap_byte_size = MaxHeapSize; 53 _min_heap_byte_size = Arguments::min_heap_size(); 54 }