From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030495AbXD1BnW (ORCPT ); Fri, 27 Apr 2007 21:43:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030869AbXD1BnW (ORCPT ); Fri, 27 Apr 2007 21:43:22 -0400 Received: from smtp1.linux-foundation.org ([65.172.181.25]:56488 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030495AbXD1BnV (ORCPT ); Fri, 27 Apr 2007 21:43:21 -0400 Date: Fri, 27 Apr 2007 18:42:58 -0700 From: Andrew Morton To: ego@in.ibm.com Cc: Oleg Nesterov , "Rafael J. Wysocki" , "Eric W. Biederman" , LKML Subject: Re: 2.6.21-rc7-mm1: BUG_ON in kthread_bind during _cpu_down Message-Id: <20070427184258.62794053.akpm@linux-foundation.org> In-Reply-To: <20070426125838.GC12892@in.ibm.com> References: <200704260110.22224.rjw@sisk.pl> <20070425165410.b73443b4.akpm@linux-foundation.org> <20070426100922.GB12892@in.ibm.com> <20070426101547.GA97@tv-sign.ru> <20070426125838.GC12892@in.ibm.com> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.6; i686-pc-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 On Thu, 26 Apr 2007 18:28:38 +0530 Gautham R Shenoy wrote: > I just checked with Vatsa if there was any subtle reason why they > had put in the kthread_bind() in cpu.c. Vatsa cannot seem to recollect > any and I can't see any. So let us just remove the kthread_bind. > > Signed-off-by: Gautham R Shenoy > --- > kernel/cpu.c | 4 ---- > 1 files changed, 4 deletions(-) > > Index: linux-2.6.21-rc7/kernel/cpu.c > =================================================================== > --- linux-2.6.21-rc7.orig/kernel/cpu.c > +++ linux-2.6.21-rc7/kernel/cpu.c > @@ -176,10 +176,6 @@ static int _cpu_down(unsigned int cpu, i > /* This actually kills the CPU. */ > __cpu_die(cpu); > > - /* Move it here so it can run. */ > - kthread_bind(p, get_cpu()); > - put_cpu(); > - > /* CPU is completely dead: tell everyone. Too late to complain. */ > if (raw_notifier_call_chain(&cpu_chain, CPU_DEAD | mod, > hcpu) == NOTIFY_BAD) So I cooked up a changelog and queued up the diff. But I have an uneasy feeling that things are getting a bit close to guesswork here. We have a huge amount of change pending in the kthread/workqueue/freezer area, partly because I decided not to merge most of the workqueue changes into 2.6.21. It'd be good if people could take some time to sit down and re-review the code which we presently have. I plan on sending it all off for 2.6.22 and there might be some glitches but it seems to have a good track record so far.