From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx194.postini.com [74.125.245.194]) by kanga.kvack.org (Postfix) with SMTP id A30046B0062 for ; Thu, 15 Nov 2012 21:50:56 -0500 (EST) Received: from /spool/local by e23smtp07.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 16 Nov 2012 12:46:47 +1000 Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay04.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id qAG2eM0j65863888 for ; Fri, 16 Nov 2012 13:40:23 +1100 Received: from d23av02.au.ibm.com (loopback [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id qAG2okAi009490 for ; Fri, 16 Nov 2012 13:50:46 +1100 Message-ID: <50A5AA03.2000707@linux.vnet.ibm.com> Date: Fri, 16 Nov 2012 10:50:43 +0800 From: Michael Wang MIME-Version: 1.0 Subject: Re: [3.6.6] panic on reboot / khungtaskd blocked? (WARNING: at arch/x86/kernel/smp.c:123 native_smp_send_reschedule) References: <56378024.A3Kec8xZj0@pawels> <2413953.H7iie8v1th@pawels> <50A302C9.2060800@linux.vnet.ibm.com> <1984533.1jAeFKDqSR@localhost> <50A44854.6040905@linux.vnet.ibm.com> <20121115094046.GD1394@quack.suse.cz> In-Reply-To: <20121115094046.GD1394@quack.suse.cz> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Jan Kara Cc: =?UTF-8?B?UGF3ZcWCIFNpa29yYQ==?= , linux-kernel@vger.kernel.org, stable@vger.kernel.org, torvalds@linux-foundation.org, arekm@pld-linux.org, baggins@pld-linux.org, Alexander Viro , Fengguang Wu , Johannes Weiner , linux-mm@kvack.org On 11/15/2012 05:40 PM, Jan Kara wrote: > On Thu 15-11-12 09:41:40, Michael Wang wrote: >> On 11/15/2012 05:10 AM, PaweA? Sikora wrote: >>> On Wednesday 14 of November 2012 10:32:41 Michael Wang wrote: >>>> On 11/13/2012 05:40 PM, PaweA? Sikora wrote: >>>>> On Monday 12 of November 2012 13:33:39 PaweA? Sikora wrote: >>>>>> On Monday 12 of November 2012 11:22:47 PaweA? Sikora wrote: >>>>>>> On Monday 12 of November 2012 15:40:31 Michael Wang wrote: >>>>>>>> On 11/12/2012 03:16 PM, PaweA? Sikora wrote: >>>>>>>>> On Monday 12 of November 2012 11:04:12 Michael Wang wrote: >>>>>>>>>> On 11/09/2012 09:48 PM, PaweA? Sikora wrote: >>>>>>>>>>> Hi, >>>>>>>>>>> >>>>>>>>>>> during playing with new ups i've caught an nice oops on reboot: >>>>>>>>>>> >>>>>>>>>>> http://imgbin.org/index.php?page=image&id=10253 >>>>>>>>>>> >>>>>>>>>>> probably the upstream is also affected. >>>>>>>>>> >>>>>>>>>> Hi, PaweA? >>>>>>>>>> >>>>>>>>>> Are you using a clean 3.6.6 without any modify? >>>>>>>>> >>>>>>>>> yes, pure 3.6.6 form git tree with modular config. >>>>>>>>> >>>>>>>>>> Looks like some threads has set itself to be UNINTERRUPTIBLE with out >>>>>>>>>> any design on switch itself back later(or the time is too long), are you >>>>>>>>>> accidentally using some bad designed module? >>>>>>>>> >>>>>>>>> hmm, hard to say. mostly all modules are loaded automatically by kernel. >>>>>>>> >>>>>>>> Could you please provide the whole dmesg in text? your picture lost the >>>>>>>> print info of the hung task. >>>>>>> >>>>>>> i've grabbed the console via rs232 but there's no more info (see attached txt). >>>>>> >>>>>> hmm, i have one observation. >>>>>> >>>>>> during rc.shutdown there're messages on console like this: Cannot stat file /proc/$pid/fd/1: Connection timed out >>>>>> afaics this file descriptor points to vnc log file on a remote machine, e.g.: >>>>>> >>>>>> # ps aux|grep xfwm4 >>>>>> eda 1748 0.0 0.0 320220 11224 ? S 13:08 0:00 xfwm4 >>>>>> >>>>>> # readlink -m /proc/1748/fd/1 >>>>>> /remote/dragon/ahome/eda/.vnc/odra:11.log >>>>>> >>>>>> # mount|grep ahome >>>>>> dragon:/home/users/ on /remote/dragon/ahome type nfs (rw,relatime,vers=3,rsize=262144,wsize=262144,namlen=255,soft,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=10.0.2.121,mountvers=3,mountport=45251,mountproto=udp,local_lock=none,addr=10.0.2.121) >>>>>> >>>>>> >>>>>> so, probably during `killall5 -TERM/-KILL` on shutdown stage something sometimes go wrong >>>>>> and these processes (xfce4/vncserver) survive the signal and hang on the nfs i/o. >>>>>> >>>>> >>>>> ok, now i have full sysrq+w backtraces from shutdown process. i hope i'll help you. >>>> >>>> This can only tell us what's the task in UNINTERRUPTABLE state, but with >>>> out time info, we can't find out which one is the hung task... >> >> So it's blocked on __lock_page() for too long? >> Add more experts in mm aspect to cc. > It's really NFS related. E.g. in trace > https://lkml.org/lkml/2012/11/14/657 we are waiting on PageWriteback bit > in fact - i.e. we have submitted data to the NFS server and are waiting for > its response that the data was written. Do you mean, NFS lock some page, then wait on a respond which not come in? Regards, Michael Wang > > Honza > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org