Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932587AbWBDXvp (ORCPT ); Sat, 4 Feb 2006 18:51:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1946153AbWBDXvX (ORCPT ); Sat, 4 Feb 2006 18:51:23 -0500 Received: from smtp.osdl.org ([65.172.181.4]:24988 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1030216AbWBDXvR (ORCPT ); Sat, 4 Feb 2006 18:51:17 -0500 Date: Sat, 4 Feb 2006 15:50:19 -0800 From: Andrew Morton To: Paul Jackson Cc: steiner@sgi.com, dgc@sgi.com, Simon.Derr@bull.net, ak@suse.de, linux-kernel@vger.kernel.org, pj@sgi.com, clameter@sgi.com Subject: Re: [PATCH 4/5] cpuset memory spread slab cache optimizations Message-Id: <20060204155019.47f313d7.akpm@osdl.org> In-Reply-To: <20060204071927.10021.75308.sendpatchset@jackhammer.engr.sgi.com> References: <20060204071910.10021.8437.sendpatchset@jackhammer.engr.sgi.com> <20060204071927.10021.75308.sendpatchset@jackhammer.engr.sgi.com> X-Mailer: Sylpheed version 1.0.4 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 787 Lines: 23 Paul Jackson wrote: > > +void mpol_set_task_struct_flag(struct task_struct *p) > +{ > + if (p->mempolicy) > + p->flags |= PF_MEMPOLICY; > + else > + p->flags &= ~PF_MEMPOLICY; > +} As mentioned before, if we ever modify tsk->flags, where tsk != current, we have a nasty race. So this function's interface really does invite that race and hence is not very good. As we do seem to be only calling it for current or for a newly-created task I guess the access is OK, so perhaps a weaselly comment would cover that worry. - 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/