From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755969AbYCIRMW (ORCPT ); Sun, 9 Mar 2008 13:12:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752914AbYCIRJZ (ORCPT ); Sun, 9 Mar 2008 13:09:25 -0400 Received: from viefep25-int.chello.at ([62.179.121.45]:25079 "EHLO viefep25-int.chello.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752341AbYCIRJU (ORCPT ); Sun, 9 Mar 2008 13:09:20 -0400 X-SourceIP: 80.56.237.116 Message-Id: <20080309170929.883491000@chello.nl> References: <20080309170850.256853000@chello.nl> User-Agent: quilt/0.45-1 Date: Sun, 09 Mar 2008 18:09:07 +0100 From: Peter Zijlstra To: LKML , Ingo Molnar Cc: Dmitry Adamushko , Mike Galbraith , Dhaval Giani , Srivatsa Vaddagiri , Peter Zijlstra Subject: [RFC/PATCH 17/17] sched: fair: optimize the elegebility test Content-Disposition: inline; filename=sched-fair-avg_runtime-opt.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Suggested by Dmitry Adamushko; trade a div for a mult. Signed-off-by: Peter Zijlstra --- kernel/sched_fair.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) Index: linux-2.6-2/kernel/sched_fair.c =================================================================== --- linux-2.6-2.orig/kernel/sched_fair.c +++ linux-2.6-2/kernel/sched_fair.c @@ -339,6 +339,12 @@ s64 avg_vruntime(struct cfs_root_rq *cfs } static inline +int avg_vruntime_cmp(struct cfs_root_rq *cfs_r_rq, s64 vruntime) +{ + return (vruntime * cfs_r_rq->nr_queued) <= cfs_r_rq->avg_vruntime; +} + +static inline s64 entity_deadline_key(struct cfs_root_rq *cfs_r_rq, struct sched_entity *se) { return se->vruntime + se->vperiod - cfs_r_rq->min_vruntime; @@ -430,11 +436,10 @@ static struct sched_entity *__pick_next_ */ static struct sched_entity *__pick_next_entity(struct cfs_root_rq *cfs_r_rq) { - struct sched_entity *next_deadline; - s64 avg = avg_vruntime(cfs_r_rq); + struct sched_entity *next_deadline = __pick_next_deadline(cfs_r_rq); + s64 vruntime = entity_timeline_key(cfs_r_rq, next_deadline); - next_deadline = __pick_next_deadline(cfs_r_rq); - if (entity_timeline_key(cfs_r_rq, next_deadline) <= avg) + if (avg_vruntime_cmp(cfs_r_rq, vruntime)) return next_deadline; return __pick_next_timeline(cfs_r_rq); --