jdk8-mips64-public/hotspot: src/share/vm/runtime/orderAccess.cpp@a6bff45449bc

6973570: OrderAccess::storestore() scales poorly on multi-socket x64 and sparc: cache-line ping-ponging
Summary: volatile store to static variable removed in favour of a volatile store to stack to avoid excessive cache coherency traffic; verified that the volatile store is not elided by any of our current compilers.
Reviewed-by: dholmes, dice, jcoomes, kvn

     1 /*

     2  * Copyright (c) 2003, 2010, 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  */

    25 # include "incls/_precompiled.incl"

    26 # include "incls/_orderAccess.cpp.incl"

    28 void OrderAccess::StubRoutines_fence() {

    29   // Use a stub if it exists.  It may not exist during bootstrap so do

    30   // nothing in that case but assert if no fence code exists after threads have been created

    31   void (*func)() = CAST_TO_FN_PTR(void (*)(), StubRoutines::fence_entry());

    33   if (func != NULL) {

    34     (*func)();

    35     return;

    36   }

    37   assert(Threads::number_of_threads() == 0, "for bootstrap only");

    38 }

Mercurial > jdk8-mips64-public > hotspot / file revision

src/share/vm/runtime/orderAccess.cpp@a6bff45449bc

src/share/vm/runtime/orderAccess.cpp