From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758776Ab0IHNXj (ORCPT ); Wed, 8 Sep 2010 09:23:39 -0400 Received: from mail-wy0-f174.google.com ([74.125.82.174]:39998 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755591Ab0IHNXi (ORCPT ); Wed, 8 Sep 2010 09:23:38 -0400 From: fabio de francesco Organization: metanix.org To: LKML Subject: Re: linux/kernel/sched.c: context_switch(). Date: Wed, 8 Sep 2010 15:23:40 +0200 User-Agent: KMail/1.13.5 (Linux/2.6.35-tuxonice-r1-100826; KDE/4.4.5; x86_64; ; ) References: <201009081508.30490.fabio@metanix.org> In-Reply-To: MIME-Version: 1.0 Message-Id: <201009081523.41718.fabio@metanix.org> Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 08 September 2010 15:10:49 you wrote: > Long day? Do you mean likely(!mm) actually means unlikely(0)? No, no. I am sorry for my poor English. I mean:"likely(!mm)" is like "likely(0)". > On 8 September 2010 20:08, fabio de francesco wrote: > > There must be something I am missing in sched.c at context_switch() > > function definition. > > > > There I can read the following code: > > > > static inline void > > context_switch(struct rq *rq, struct task_struct *prev, > > struct task_struct *next) > > { > > ... > > struct mm_struct *mm; > > mm = next->mm; > > if (likely(!mm)) { > > next->active_mm = oldmm; > > atomic_inc(&oldmm->mm_count); > > enter_lazy_tlb(oldmm, next); > > } else > > switch_mm(oldmm, mm, next); > > ... > > } > > > > May someone please explain why the mm pointer is likely supposed to be > > NULL? > > > > Thanks in advance. > > > > fabio > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" > > in the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/