From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755297Ab2HVCIA (ORCPT ); Tue, 21 Aug 2012 22:08:00 -0400 Received: from e23smtp08.au.ibm.com ([202.81.31.141]:56223 "EHLO e23smtp08.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754998Ab2HVCH4 (ORCPT ); Tue, 21 Aug 2012 22:07:56 -0400 Message-ID: <50343EF1.5060008@linux.vnet.ibm.com> Date: Wed, 22 Aug 2012 10:07:45 +0800 From: Michael Wang User-Agent: Mozilla/5.0 (X11; Linux i686; rv:14.0) Gecko/20120714 Thunderbird/14.0 MIME-Version: 1.0 To: Fengguang Wu CC: Thomas Gleixner , Yinghai Lu , Suresh Siddha , LKML Subject: Re: BUG: scheduling while atomic, under native_smp_prepare_cpus() References: <20120817134944.GA539@localhost> <50320163.5080703@linux.vnet.ibm.com> <20120820092744.GA3668@localhost> <5032067E.20505@linux.vnet.ibm.com> <20120821165006.GA24559@localhost> In-Reply-To: <20120821165006.GA24559@localhost> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit x-cbid: 12082202-5140-0000-0000-000001F1F620 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/22/2012 12:50 AM, Fengguang Wu wrote: > On Mon, Aug 20, 2012 at 05:42:22PM +0800, Michael Wang wrote: >> On 08/20/2012 05:27 PM, Fengguang Wu wrote: >>> Hi Michael, >>> >>> On Mon, Aug 20, 2012 at 05:20:35PM +0800, Michael Wang wrote: >>>> On 08/17/2012 09:49 PM, Fengguang Wu wrote: >>>> >>>> Hi, FengGuang >>>> >>>> native_smp_prepare_cpus has already disabled the preempt before >>>> reach __irq_alloc_descs(), and sleep in mutex_lock() cause the bug. >>>> >>>> May be the follow patch could help to solve the issue(actually I >>>> think the true problem should be in _cond_resched...). >>> >>> Is this a debug patch? Since what it does is to conditionally disable >>> the warning. >> >> No, I use this as a solution, it should work as the bug reported in boot >> process before init_post called. >> >> We have some reference from __might_sleep which also avoid the check if >> system has not fully booted, so I think this way is acceptable, but I'm >> not the one to make decision... > > Fair enough. > >>> >>>> I can't do test by my self since I can't reproduce the issue on my >>>> machine, the kernel_init thread never got a need sched flag set at >>>> that moment in my case... >>> >>> I'll try it and report back :) >> >> Appreciate :) > > It works! :) > > Tested-by: Fengguang Wu Thanks for your testing, I will send out the patch later with your Tested-by :) Regards, Michael Wang > > Thanks, > Fengguang > -- > 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/ >