From: "J. Bruce Fields" <bfields@fieldses.org>
To: Tim Gardner <tim.gardner@canonical.com>
Cc: Neil Brown <neilb@suse.de>,
linux-nfs@vger.kernel.org,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Trond.Myklebust@netapp.com
Subject: Re: nfsd deadlock, 2.6.36-rc3
Date: Wed, 8 Sep 2010 13:50:32 -0400 [thread overview]
Message-ID: <20100908175032.GA816@fieldses.org> (raw)
In-Reply-To: <4C87BF63.3070808@canonical.com>
On Wed, Sep 08, 2010 at 10:52:51AM -0600, Tim Gardner wrote:
> The solution appears to be to twiddle with
> /proc/sys/vm/min_free_kbytes and /proc/sys/vm/drop_caches, though
> I'm not sure this addresses the root cause. Perhaps low memory
> really is the root cause.
>
> At any rate, their solution was to set min_free_kbytes to 4GB, and
> to 'echo 1 > /proc/sys/vm/drop_caches' whenever free memory fell
> below 8GB. Not particularly elegant, but it appears to have stopped
> their server from wedging.
That does sound like a workaround rather than a fix. Were there any
diagnostics left in the logs after the lockups? Could you get sysrq-t
dumps and figure out what was waiting on what? If the system was too
wedged for any of that to work, would any fo the watchdog deubgging
options help?
--b.
next prev parent reply other threads:[~2010-09-08 17:51 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-01 15:39 nfsd deadlock, 2.6.36-rc3 Tim Gardner
2010-09-01 16:54 ` J. Bruce Fields
2010-09-01 20:55 ` Neil Brown
2010-09-01 21:05 ` J. Bruce Fields
2010-09-01 21:11 ` Tim Gardner
2010-09-01 21:13 ` J. Bruce Fields
2010-09-02 15:13 ` Tim Gardner
2010-09-08 16:52 ` Tim Gardner
2010-09-08 17:50 ` J. Bruce Fields [this message]
2010-09-03 19:12 ` Maciej Rutecki
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