Date: Thu, 28 Feb 2013 12:29:16 -0500
From: "J. Bruce Fields" <bfields@fieldses.org>
To: Iordan Iordanov <iordan@cdf.toronto.edu>
Cc: linux-nfs@vger.kernel.org
Subject: Re: NFS v3 hangs with kernel version v3.2.0, 32-bit
Message-ID: <20130228172916.GA29852@fieldses.org>
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On Thu, Feb 28, 2013 at 11:24:12AM -0500, Iordan Iordanov wrote:
> Hi Bruce,
> 
> On 02/22/13 10:01, J. Bruce Fields wrote:
> >Some of that debugging is extremely verbose, yes.
> >
> >Since this list is for upstream (not ubuntu) development, most useful
> >would probably be if you could work out whether the problem is
> >reproduceable on the latest upstream kernel.
> 
> Understandable.
> 
> We've been unable to pin down what triggers this bug, so we are
> unable to reproduce it synthetically. It only appears to happen on
> shared servers with lots of NFS traffic, and in all cases it
> happened with more than a month of uptime. Also, we are unable to
> put an upstream kernel on a production machine.
> 
> These two conditions will make it exceedingly unlikely that we would
> be able to work this out with an upstream kernel.
> 
> Even if we were able to reproduce this with an upstream kernel, if
> it takes such a long time to reproduce could that have aged the
> kernel we're testing enough to invalidate our testing results?

Yes, it's certainly harder to know what to do with a fix that can't be
confirmed for months.

But there's certainly no harm in continuing to report any further
symptoms; eventually somebody may recognize the problem.

--b.