From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750848Ab1AVFEl (ORCPT ); Sat, 22 Jan 2011 00:04:41 -0500 Received: from smtp-out.google.com ([74.125.121.67]:45521 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750720Ab1AVFEj (ORCPT ); Sat, 22 Jan 2011 00:04:39 -0500 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=message-id:user-agent:date:from:to:cc:subject:references: content-disposition:x-system-of-record; b=oBSP8E0T0tBfUx9YOhZEeQJj9u20iUz9bwZSlaKTJDd6mGD5njnBi0SSCkS6BnVpo ls4GCetQZ8YEqP0Qi8JQw== Message-Id: <20110122044851.825284940@google.com> User-Agent: quilt/0.48-1 Date: Fri, 21 Jan 2011 20:45:00 -0800 From: Paul Turner To: linux-kernel@vger.kernel.org Cc: Peter Zijlstra , Ingo Molnar , Mike Galbraith , Dan Carpenter Subject: [patch 2/5] sched: (cleanup) remove redundant cfs_rq checks References: <20110122044458.058531078@google.com> Content-Disposition: inline; filename=sched-remove_cfs_rq_checks.patch X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since updates are against an entity's queuing cfs_rq it's not possible to enter update_cfs_{shares,load} with a NULL cfs_rq. (Indeed, update_cfs_load would crash prior to the check if we did anyway since we load is examined during the initializers). Also, in the update_cfs_load case there's no point in maintaining averages for rq->cfs_rq since we don't perform shares distribution at that level -- NULL check is replaced accordingly. Thanks to Dan Carpenter for pointing out the deference before NULL check. Signed-off-by: Paul Turner --- kernel/sched_fair.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) Index: tip3/kernel/sched_fair.c =================================================================== --- tip3.orig/kernel/sched_fair.c +++ tip3/kernel/sched_fair.c @@ -721,7 +721,7 @@ static void update_cfs_load(struct cfs_r u64 now, delta; unsigned long load = cfs_rq->load.weight; - if (!cfs_rq) + if (cfs_rq->tg == &root_task_group) return; now = rq_of(cfs_rq)->clock; @@ -784,9 +784,6 @@ static void update_cfs_shares(struct cfs struct sched_entity *se; long load_weight, load, shares; - if (!cfs_rq) - return; - tg = cfs_rq->tg; se = tg->se[cpu_of(rq_of(cfs_rq))]; if (!se)