From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757811Ab3BBOUy (ORCPT ); Sat, 2 Feb 2013 09:20:54 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:16662 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757613Ab3BBOT5 (ORCPT ); Sat, 2 Feb 2013 09:19:57 -0500 X-Authority-Analysis: v=2.0 cv=bJmU0YCZ c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=Ciwy3NGCPMMA:10 a=2nB7RNwxyKsA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=D8busaIx4ccA:10 a=GvQkQWPkAAAA:8 a=VwQbUJbxAAAA:8 a=pGLkceISAAAA:8 a=NufY4J3AAAAA:8 a=6kcgh8hLkRGSLAEeN_MA:9 a=QEXdDO2ut3YA:10 a=Wwjp7rKQgkIA:10 a=MSl-tDqOz04A:10 a=re9sYKne76oA:10 a=jeBq3FmKZ4MA:10 a=7sE7yg0GKJZYB-F9BzwA:9 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 74.67.115.198 Message-Id: <20130202141955.137013185@goodmis.org> User-Agent: quilt/0.60-1 Date: Sat, 02 Feb 2013 09:18:45 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Frederic Weisbecker , Christoph Lameter , Shan Wei Subject: [PATCH 03/11] tracing: Use __this_cpu_inc/dec operation instead of __get_cpu_var References: <20130202141842.189550803@goodmis.org> Content-Disposition: inline; filename=0003-tracing-Use-__this_cpu_inc-dec-operation-instead-of-.patch Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="00GvhwF7k39YY" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --00GvhwF7k39YY Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable From: Shan Wei __this_cpu_inc_return() or __this_cpu_dec generates a single instruction, which is faster than __get_cpu_var operation. Link: http://lkml.kernel.org/r/50A9C1BD.1060308@gmail.com Reviewed-by: Christoph Lameter Signed-off-by: Shan Wei Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index ca9b7df..07888e1 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1344,7 +1344,7 @@ static void __ftrace_trace_stack(struct ring_buffer *= buffer, */ preempt_disable_notrace(); =20 - use_stack =3D ++__get_cpu_var(ftrace_stack_reserve); + use_stack =3D __this_cpu_inc_return(ftrace_stack_reserve); /* * We don't need any atomic variables, just a barrier. * If an interrupt comes in, we don't care, because it would @@ -1398,7 +1398,7 @@ static void __ftrace_trace_stack(struct ring_buffer *= buffer, out: /* Again, don't let gcc optimize things here */ barrier(); - __get_cpu_var(ftrace_stack_reserve)--; + __this_cpu_dec(ftrace_stack_reserve); preempt_enable_notrace(); =20 } --=20 1.7.10.4 --00GvhwF7k39YY Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQEcBAABAgAGBQJRDSCLAAoJEOdOSU1xswtMRO8IAKtC5yylhYPtGZZyS0cCZ2oe TWL2gKs7CvsHkwZtnaxqDA46Zqtgdg8KhzqSzsoZViB6TgsU3GL4tQxZVv45RR2J OJ2G1vKX1LJeK3FGfyOfyqMhZqH3opBkw2nFyXKYkG9EnOap0PI9Ngv8lpCl2XZS QD4PdGwlv8BT7H4qo6/L4dwXIyTA4FWWb9pdjz1cN9Q8XEQwvTMf90ujHpZtIUMk LSzsbXiAKGuVuKgzPmRQDG/+EAJeJ8c/ujwDpYPGd1tv8C+UeWpRiw1T7Y5GPPdo kVbpbriHkDO9/U6D0OpM63/XQ9d+35W1znryO3132JEYP2ys96jxtOcZi5dWzrE= =3kBs -----END PGP SIGNATURE----- --00GvhwF7k39YY--