Date: Sat, 24 Aug 2013 23:51:45 -0700 From: Michael Tratz <michael@esosoft.com> To: Rick Macklem <rmacklem@uoguelph.ca> Cc: freebsd-stable@freebsd.org Subject: Re: NFS deadlock on 9.2-Beta1 Message-ID: <40674FAC-33E6-4994-819E-6B8318B9DDB3@esosoft.com> In-Reply-To: <461392652.9990692.1376602743970.JavaMail.root@uoguelph.ca> References: <461392652.9990692.1376602743970.JavaMail.root@uoguelph.ca>
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On Aug 15, 2013, at 2:39 PM, Rick Macklem <rmacklem@uoguelph.ca> wrote: > Michael Tratz wrote: >> >> On Jul 27, 2013, at 11:25 PM, Konstantin Belousov >> <kostikbel@gmail.com> wrote: >> >>> On Sat, Jul 27, 2013 at 03:13:05PM -0700, Michael Tratz wrote: >>>> Let's assume the pid which started the deadlock is 14001 (it will >>>> be a different pid when we get the results, because the machine >>>> has been restarted) >>>> >>>> I type: >>>> >>>> show proc 14001 >>>> >>>> I get the thread numbers from that output and type: >>>> >>>> show thread xxxxx >>>> >>>> for each one. >>>> >>>> And a trace for each thread with the command? >>>> >>>> tr xxxx >>>> >>>> Anything else I should try to get or do? Or is that not the data >>>> at all you are looking for? >>>> >>> Yes, everything else which is listed in the 'debugging deadlocks' >>> page >>> must be provided, otherwise the deadlock cannot be tracked. >>> >>> The investigator should be able to see the whole deadlock chain >>> (loop) >>> to make any useful advance. >> >> Ok, I have made some excellent progress in debugging the NFS >> deadlock. >> >> Rick! You are genius. :-) You found the right commit r250907 (dated >> May 22) is the definitely the problem. >> >> Here is how I did the testing: One machine received a kernel before >> r250907, the second machine received a kernel after r250907. Sure >> enough within a few hours the machine with r250907 went into the >> usual deadlock state. The machine without that commit kept on >> working fine. Then I went back to the latest revision (r253726), but >> leaving r250907 out. The machines have been running happy and rock >> solid without any deadlocks. I have expanded the testing to 3 >> machines now and no reports of any issues. >> >> I guess now Konstantin has to figure out why that commit is causing >> the deadlock. Lovely! :-) I will get that information as soon as >> possible. I'm a little behind with normal work load, but I expect to >> have the data by Tuesday evening or Wednesday. >> > Have you been able to pass the debugging info on to Kostik? > > It would be really nice to get this fixed for FreeBSD9.2. > > Thanks for your help with this, rick Sorry Rick, I wasn't able to get you guys that info quickly enough. I thought I would have enough time, before my own wedding and honeymoon came along, but everything went a little crazy and stressful. I didn't think it would be this nuts. :-) I'm caught up with everything and from what I can see from the discussions is that we know now what the problem is. I can report that the machines which I have had without r250907 have been running without any problems for 27+ days. If you need me to test any new patches, please let me know. If I should test with the partial merge of r253927 I'll be happy to do so. Thanks, Michaelhelp
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