From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422943AbXCGS2e (ORCPT ); Wed, 7 Mar 2007 13:28:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422972AbXCGS2e (ORCPT ); Wed, 7 Mar 2007 13:28:34 -0500 Received: from rgminet01.oracle.com ([148.87.113.118]:51216 "EHLO rgminet01.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422975AbXCGS2b (ORCPT ); Wed, 7 Mar 2007 13:28:31 -0500 Date: Wed, 7 Mar 2007 10:25:22 -0800 From: Randy Dunlap To: cpw@sgi.com (Cliff Wickman) Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/1] hotplug cpu: migrate a task within its cpuset Message-Id: <20070307102522.98b40c81.randy.dunlap@oracle.com> In-Reply-To: <45EECB2C.mailxEK515UYJW@eag09.americas.sgi.com> References: <45EECB2C.mailxEK515UYJW@eag09.americas.sgi.com> Organization: Oracle Linux Eng. X-Mailer: Sylpheed 2.3.1 (GTK+ 2.8.10; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAQAAAAI= X-Brightmail-Tracker: AAAAAQAAAAI= X-Whitelist: TRUE X-Whitelist: TRUE Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 07 Mar 2007 08:24:44 -0600 Cliff Wickman wrote: > > From: Cliff Wickman > > When a cpu is disabled, move_task_off_dead_cpu() is called for tasks > that have been running on that cpu. > > Currently, such a task is migrated: > 1) to any cpu on the same node as the disabled cpu, which is both online > and among that task's cpus_allowed > 2) to any cpu which is both online and among that task's cpus_allowed > > But the task's cpus_allowed may have been a single cpu. > > This patch would insert a preference to migrate such a task to a cpu within > its cpuset (and set its cpus_allowed to its cpuset). > > With this patch, migrate the task to: > 1) to any cpu on the same node as the disabled cpu, which is both online > and among that task's cpus_allowed > 2) to any online cpu within the task's cpuset > 3) to any cpu which is both online and among that task's cpus_allowed > > > Diffed against 2.6.16.37 Wow. Why? or did you want this applied only to the 2.6.16.* stable kernel? |--- linux.orig/kernel/sched.c |+++ linux/kernel/sched.c -------------------------- Patching file kernel/sched.c using Plan A... Hunk #1 succeeded at 5032 with fuzz 2 (offset 430 lines). Hmm... Ignoring the trailing garbage. done I'm surprised that none of Documentation/SubmittingPatches or The Perfect Patch (http://www.zip.com.au/~akpm/linux/patches/stuff/tpp.txt) or Jeff Garzik's patch-format page (http://linux.yyz.us/patch-format.html) (AFAICT) mention that patches should be made against "current" or "recent" or "head of tree" or some such words. I'll "fix" Doc/SubmittingPatches... and/or Doc/SubmitChecklist. > Signed-off-by: Cliff Wickman > > --- > kernel/sched.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > Index: linux/kernel/sched.c > =================================================================== > --- linux.orig/kernel/sched.c > +++ linux/kernel/sched.c > @@ -4602,6 +4602,12 @@ static void move_task_off_dead_cpu(int d > if (dest_cpu == NR_CPUS) > dest_cpu = any_online_cpu(tsk->cpus_allowed); > > + /* try to stay on the same cpuset */ > + if (dest_cpu == NR_CPUS) { > + tsk->cpus_allowed = cpuset_cpus_allowed(tsk); > + dest_cpu = any_online_cpu(tsk->cpus_allowed); > + } > + > /* No more Mr. Nice Guy. */ > if (dest_cpu == NR_CPUS) { > cpus_setall(tsk->cpus_allowed); > - > 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/ > --- ~Randy *** Remember to use Documentation/SubmitChecklist when testing your code ***