• file
• revisions
• annotate
• diff
• comparison
• raw

src/share/vm/runtime/orderAccess.cpp@a6bff45449bc (annotated)

src/share/vm/runtime/orderAccess.cpp

Tue, 10 Aug 2010 14:53:35 -0700

author

ysr

date

Tue, 10 Aug 2010 14:53:35 -0700

changeset 2066

a6bff45449bc

parent 1907

c18cbe5936b8

child 2314

f95d63e2154a

permissions

-rw-r--r--

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

duke@435	1	/*
ysr@2066	2	* Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
duke@435	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435	4	*
duke@435	5	* This code is free software; you can redistribute it and/or modify it
duke@435	6	* under the terms of the GNU General Public License version 2 only, as
duke@435	7	* published by the Free Software Foundation.
duke@435	8	*
duke@435	9	* This code is distributed in the hope that it will be useful, but WITHOUT
duke@435	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435	12	* version 2 for more details (a copy is included in the LICENSE file that
duke@435	13	* accompanied this code).
duke@435	14	*
duke@435	15	* You should have received a copy of the GNU General Public License version
duke@435	16	* 2 along with this work; if not, write to the Free Software Foundation,
duke@435	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435	18	*
trims@1907	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907	20	* or visit www.oracle.com if you need additional information or have any
trims@1907	21	* questions.
duke@435	22	*
duke@435	23	*/
duke@435	24
duke@435	25	# include "incls/_precompiled.incl"
duke@435	26	# include "incls/_orderAccess.cpp.incl"
duke@435	27
never@1106	28	void OrderAccess::StubRoutines_fence() {
never@1106	29	// Use a stub if it exists. It may not exist during bootstrap so do
never@1106	30	// nothing in that case but assert if no fence code exists after threads have been created
never@1106	31	void (*func)() = CAST_TO_FN_PTR(void (*)(), StubRoutines::fence_entry());
never@1106	32
never@1106	33	if (func != NULL) {
never@1106	34	(*func)();
never@1106	35	return;
never@1106	36	}
never@1106	37	assert(Threads::number_of_threads() == 0, "for bootstrap only");
never@1106	38	}