From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754083AbYLPHsf (ORCPT ); Tue, 16 Dec 2008 02:48:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754359AbYLPHrx (ORCPT ); Tue, 16 Dec 2008 02:47:53 -0500 Received: from casper.infradead.org ([85.118.1.10]:46933 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754096AbYLPHrw (ORCPT ); Tue, 16 Dec 2008 02:47:52 -0500 Message-Id: <20081216074636.090411199@chello.nl> References: <20081216074529.570706654@chello.nl> User-Agent: quilt/0.46-1 Date: Tue, 16 Dec 2008 08:45:31 +0100 From: Peter Zijlstra To: mingo@elte.hu, efault@gmx.de Cc: linux-kernel@vger.kernel.org, Peter Zijlstra Subject: [PATCH 2/3] sched: optimize update_curr() Content-Disposition: inline; filename=sched-opt-update_curr_fair.patch X-Bad-Reply: References but no 'Re:' in Subject. Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Skip the hard work when there is none. Signed-off-by: Peter Zijlstra Acked-by: Mike Galbraith --- kernel/sched_fair.c | 2 ++ 1 file changed, 2 insertions(+) Index: linux-2.6/kernel/sched_fair.c =================================================================== --- linux-2.6.orig/kernel/sched_fair.c +++ linux-2.6/kernel/sched_fair.c @@ -492,6 +492,8 @@ static void update_curr(struct cfs_rq *c * overflow on 32 bits): */ delta_exec = (unsigned long)(now - curr->exec_start); + if (!delta_exec) + return; __update_curr(cfs_rq, curr, delta_exec); curr->exec_start = now; --