Date: Mon, 14 Feb 2011 22:25:28 +0100
From: Jan Kara <jack@suse.cz>
To: Jesper Krogh <jesper@krogh.cc>
Cc: Jan Kara <jack@suse.cz>, linux-kernel@vger.kernel.org,
        Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Subject: Re: sync hangs - 2.6.35.10
Message-ID: <20110214212528.GG3018@quack.suse.cz>
References: <4D47A99A.6050204@krogh.cc>
 <20110201121457.GA2059@quack.suse.cz>
 <4D59999E.9040302@krogh.cc>
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On Mon 14-02-11 22:07:42, Jesper Krogh wrote:
> On 2011-02-01 13:14, Jan Kara wrote:
> >   Definitely. There have been several patches fixing livelock issues
> >in this area under various conditions. Considering your use case, you
> >might be hit by problems being fixed by commits:
> >6585027a5e8cb490e3a761b2f3f3c3acf722aff2
> >aa373cf550994623efb5d49a4d8775bafd10bbc1
> >b9543dac5bbc4aef0a598965b6b34f6259ab9a9b
> >(went into 2.6.38-rc1)
> I couldn't get above to apply on a 2.6.35.10 kernel, but applied to
> a 2.6.37 the problem seems solved. Have they been queued up for stable?
  I don't think so but it's a good idea. Will send them there.

> >possibly also older
> >7624ee72aa09334af072853457a5d46d9901c3f8
> >(in 2.6.36-rc1)
> This one alone applied to 2.6.35 didn't solve it.
> 
> jk@clyde:~$ time sync
> 
> real    19m2.650s
> user    0m0.000s
> sys    0m0.030s
> 
> Without notable disk-activity while waiting. (<5MB/s measured using dstat)
> This sample was "decent" I've seen sync times over 2 horus on this system
> with 128GB of memory.. again without any notable disk-activity while
> waiting.
  Hmm, then I suspect you hit the case fixed by commit
b9543dac5bbc4aef0a598965b6b34f6259ab9a9b. Anyway, glad to hear you don't
see the problems anymore. Thanks for letting me know your results :).

								Honza
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR