From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752889Ab2AaIsp (ORCPT ); Tue, 31 Jan 2012 03:48:45 -0500 Received: from e28smtp09.in.ibm.com ([122.248.162.9]:51479 "EHLO e28smtp09.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752015Ab2AaIsn (ORCPT ); Tue, 31 Jan 2012 03:48:43 -0500 Date: Tue, 31 Jan 2012 14:18:30 +0530 From: Kamalesh Babulal To: Rakib Mullick Cc: mingo@elte.hu, a.p.zijlstra@chello.nl, linux-kernel@vger.kernel.org Subject: Re: [PATCH] sched: At sched_fork use __set_task_cpu(). Message-ID: <20120131084830.GA22077@linux.vnet.ibm.com> Reply-To: Kamalesh Babulal References: <1327854877.8504.3.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <1327854877.8504.3.camel@localhost.localdomain> User-Agent: Mutt/1.5.21 (2010-09-15) x-cbid: 12013108-2674-0000-0000-0000032D1E2E Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Rakib Mullick [2012-01-29 22:34:37]: > We don't use select_task_rq() from sched_fork() anymore and no chance of task gets migrated at > this point. Therefore, we can avoid task migration related checking/accounting, so use > __set_task_cpu() instead of set_task_cpu(). > > Signed-off-by: Rakib Mullick Reviewed-by: Kamalesh Babulal > --- > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index df00cb0..a38026e 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -1755,7 +1755,7 @@ void sched_fork(struct task_struct *p) > * Silence PROVE_RCU. > */ > raw_spin_lock_irqsave(&p->pi_lock, flags); > - set_task_cpu(p, cpu); > + __set_task_cpu(p, cpu); > raw_spin_unlock_irqrestore(&p->pi_lock, flags); > > #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) > > > --