From: NeilBrown <neilb@suse.de>
To: Milan Broz <mbroz@redhat.com>
Cc: linux-raid@vger.kernel.org
Subject: Re: md raid5 fsync deadlock
Date: Thu, 1 Mar 2012 12:53:25 +1100 [thread overview]
Message-ID: <20120301125325.2b17e5f8@notabene.brown> (raw)
In-Reply-To: <4F4EB53C.6060901@redhat.com>
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On Thu, 01 Mar 2012 00:31:08 +0100 Milan Broz <mbroz@redhat.com> wrote:
> Hi Neil,
>
> I am repeatedly getting deadlock with MD raid5 & running fio check.
>
> array created just this way
> # mdadm -C -l 5 -n 4 -c 64 --assume-clean /dev/md0 /dev/sd[bcde]
>
> and running this test (on quadcore CPU)
>
> # fio --name=global --rw=randwrite --size=1G --bsrange=1k-128k --filename=/dev/md0 --name=job1 --name=job2 --name=job3 --name=job4 --end_fsync=1
>
> deadlocks in final fsync()
>
> I can reproduce it on Fedora 3.2.7 kernel (and also 3.3.0-rc5),
> below is part of the sysrq trace (full sysrq in attached gz archive)
>
> I was able to simulate it even when resync is running, it stopped
> resync process as well.
>
> Please let me know if you need more information.
>
Are you certain it is a deadlock? No forward progress at all?
What is in md/stripe_cache_size? Does it change?
What happens if you double the number in stripe_cache_size? What if you
double it again?
NeilBrown
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next prev parent reply other threads:[~2012-03-01 1:53 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-29 23:31 md raid5 fsync deadlock Milan Broz
2012-03-01 1:53 ` NeilBrown [this message]
2012-03-01 8:46 ` Milan Broz
2012-03-04 9:20 ` NeilBrown
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