src/share/vm/gc_implementation/g1/heapRegionBounds.inline.hpp

Fri, 10 Oct 2014 15:51:58 +0200

author
tschatzl
date
Fri, 10 Oct 2014 15:51:58 +0200
changeset 7257
e7d0505c8a30
parent 7137
5248357b7113
permissions
-rw-r--r--

8059758: Footprint regressions with JDK-8038423
Summary: Changes in JDK-8038423 always initialize (zero out) virtual memory used for auxiliary data structures. This causes a footprint regression for G1 in startup benchmarks. This is because they do not touch that memory at all, so the operating system does not actually commit these pages. The fix is to, if the initialization value of the data structures matches the default value of just committed memory (=0), do not do anything.
Reviewed-by: jwilhelm, brutisso

sjohanss@7137 1 /*
sjohanss@7137 2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
sjohanss@7137 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
sjohanss@7137 4 *
sjohanss@7137 5 * This code is free software; you can redistribute it and/or modify it
sjohanss@7137 6 * under the terms of the GNU General Public License version 2 only, as
sjohanss@7137 7 * published by the Free Software Foundation.
sjohanss@7137 8 *
sjohanss@7137 9 * This code is distributed in the hope that it will be useful, but WITHOUT
sjohanss@7137 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
sjohanss@7137 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
sjohanss@7137 12 * version 2 for more details (a copy is included in the LICENSE file that
sjohanss@7137 13 * accompanied this code).
sjohanss@7137 14 *
sjohanss@7137 15 * You should have received a copy of the GNU General Public License version
sjohanss@7137 16 * 2 along with this work; if not, write to the Free Software Foundation,
sjohanss@7137 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
sjohanss@7137 18 *
sjohanss@7137 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
sjohanss@7137 20 * or visit www.oracle.com if you need additional information or have any
sjohanss@7137 21 * questions.
sjohanss@7137 22 *
sjohanss@7137 23 */
sjohanss@7137 24
sjohanss@7137 25 #include "gc_implementation/g1/heapRegionBounds.hpp"
sjohanss@7137 26
sjohanss@7137 27 size_t HeapRegionBounds::min_size() {
sjohanss@7137 28 return MIN_REGION_SIZE;
sjohanss@7137 29 }
sjohanss@7137 30
sjohanss@7137 31 size_t HeapRegionBounds::max_size() {
sjohanss@7137 32 return MAX_REGION_SIZE;
sjohanss@7137 33 }
sjohanss@7137 34
sjohanss@7137 35 size_t HeapRegionBounds::target_number() {
sjohanss@7137 36 return TARGET_REGION_NUMBER;
sjohanss@7137 37 }

mercurial