From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754668Ab0KWXwH (ORCPT ); Tue, 23 Nov 2010 18:52:07 -0500 Received: from smtp109.prem.mail.ac4.yahoo.com ([76.13.13.92]:48922 "HELO smtp109.prem.mail.ac4.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754544Ab0KWXwC (ORCPT ); Tue, 23 Nov 2010 18:52:02 -0500 X-Yahoo-SMTP: _Dag8S.swBC1p4FJKLCXbs8NQzyse1SYSgnAbY0- X-YMail-OSG: Fq8QPO8VM1mimf7aIl6COnm.MgcFHU1C3he42A6GSmGdJvT JW1EALN5ZXMWK15_vLh9Odh4L3sUb_IWgPRrImxcePLk09V4xOgkwT8k2fpE 5zSi1HTrsFdpJ831lrzYYYOCeI9R9AKkqezYI85OG66vr1Ema4NjEVHt71a3 STJfJRrDVpErza5kzmZI0gcS0si_ETLjWR98jYRCVDDKXmQ8bGzh5ptaHOAe 3Y_pAfmvMRnKuv_NJXtxTDJaCaT_VI4voxYOmzm84MHn_Q.b1ilOFZoKjXfa 3scFyAfLeP9uvpAA2WgU- X-Yahoo-Newman-Property: ymail-3 Message-Id: <20101123235159.397444837@linux.com> User-Agent: quilt/0.48-1 Date: Tue, 23 Nov 2010 17:51:45 -0600 From: Christoph Lameter To: akpm@linux-foundation.org Cc: Pekka Enberg Cc: linux-kernel@vger.kernel.org Cc: Eric Dumazet Cc: Mathieu Desnoyers Cc: Tejun Heo Subject: [thiscpuops upgrade 06/10] vmstat: Use this_cpu_inc_return for vm statistics References: <20101123235139.908255844@linux.com> Content-Disposition: inline; filename=this_cpu_add_vmstat Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org this_cpu_inc_return() saves us a memory access there. Code size does not change. Signed-off-by: Christoph Lameter --- mm/vmstat.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) Index: linux-2.6/mm/vmstat.c =================================================================== --- linux-2.6.orig/mm/vmstat.c 2010-11-23 16:35:19.000000000 -0600 +++ linux-2.6/mm/vmstat.c 2010-11-23 16:45:24.000000000 -0600 @@ -227,9 +227,7 @@ void __inc_zone_state(struct zone *zone, s8 * __percpu p = pcp->vm_stat_diff + item; int v, t; - __this_cpu_inc(*p); - - v = __this_cpu_read(*p); + v = __this_cpu_inc_return(*p); t = __this_cpu_read(pcp->stat_threshold); if (unlikely(v > t)) { int overstep = t / 2; @@ -251,9 +249,7 @@ void __dec_zone_state(struct zone *zone, s8 * __percpu p = pcp->vm_stat_diff + item; int v, t; - __this_cpu_dec(*p); - - v = __this_cpu_read(*p); + v = __this_cpu_dec_return(*p); t = __this_cpu_read(pcp->stat_threshold); if (unlikely(v < - t)) { int overstep = t / 2;