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From: Dave Hansen <dave@linux.vnet.ibm.com>
To: CAI Qian <caiqian@redhat.com>
Cc: linux-mm <linux-mm@kvack.org>,
	linux-kernel@vger.kernel.org, aarcange <aarcange@redhat.com>
Subject: Re: kswapd hung tasks in 2.6.38-rc1
Date: Mon, 31 Jan 2011 14:40:16 -0800	[thread overview]
Message-ID: <1296513616.7797.4929.camel@nimitz> (raw)
In-Reply-To: <1296507528.7797.4609.camel@nimitz>

On Mon, 2011-01-31 at 12:58 -0800, Dave Hansen wrote:
> On Thu, 2011-01-20 at 03:55 -0500, CAI Qian wrote:
> > When running LTP oom01 [1] testing, the allocation process stopped
> > processing right after starting to swap.
> 
> I'm seeing the same stuff, but on -rc2.  I thought it was
> transparent-hugepage-related, but I don't see much of a trace of it in
> the stack dumps.
> 
> http://sr71.net/~dave/ibm/config-v2.6.38-rc2
> 
> It happened to me as well around the time that things started to hit
> swap.

Still not a very good data point, but I ran a heavy swap load for an
hour or so without reproducing this.  But, it happened again after I
enabled transparent huge pages.  I managed to get a sysrq-t dump out of
it:

	http://sr71.net/~dave/ibm/2.6.38-rc2-hang-0.txt

khugepaged is one of the three running tasks.  Note, I set both its
sleep timeouts to zero to stress it out a bit.

I'll keep trying to reproduce without THP.

-- Dave


WARNING: multiple messages have this Message-ID (diff)
From: Dave Hansen <dave@linux.vnet.ibm.com>
To: CAI Qian <caiqian@redhat.com>
Cc: linux-mm <linux-mm@kvack.org>,
	linux-kernel@vger.kernel.org, aarcange <aarcange@redhat.com>
Subject: Re: kswapd hung tasks in 2.6.38-rc1
Date: Mon, 31 Jan 2011 14:40:16 -0800	[thread overview]
Message-ID: <1296513616.7797.4929.camel@nimitz> (raw)
In-Reply-To: <1296507528.7797.4609.camel@nimitz>

On Mon, 2011-01-31 at 12:58 -0800, Dave Hansen wrote:
> On Thu, 2011-01-20 at 03:55 -0500, CAI Qian wrote:
> > When running LTP oom01 [1] testing, the allocation process stopped
> > processing right after starting to swap.
> 
> I'm seeing the same stuff, but on -rc2.  I thought it was
> transparent-hugepage-related, but I don't see much of a trace of it in
> the stack dumps.
> 
> http://sr71.net/~dave/ibm/config-v2.6.38-rc2
> 
> It happened to me as well around the time that things started to hit
> swap.

Still not a very good data point, but I ran a heavy swap load for an
hour or so without reproducing this.  But, it happened again after I
enabled transparent huge pages.  I managed to get a sysrq-t dump out of
it:

	http://sr71.net/~dave/ibm/2.6.38-rc2-hang-0.txt

khugepaged is one of the three running tasks.  Note, I set both its
sleep timeouts to zero to stress it out a bit.

I'll keep trying to reproduce without THP.

-- Dave

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  reply	other threads:[~2011-01-31 22:40 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <2056664954.83361.1295513496286.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com>
2011-01-20  8:55 ` kswapd hung tasks in 2.6.38-rc1 CAI Qian
2011-01-20  8:55   ` CAI Qian
2011-01-31 20:58   ` Dave Hansen
2011-01-31 20:58     ` Dave Hansen
2011-01-31 22:40     ` Dave Hansen [this message]
2011-01-31 22:40       ` Dave Hansen
2011-01-31 23:13       ` Andrea Arcangeli
2011-01-31 23:13         ` Andrea Arcangeli
2011-01-31 23:20         ` Dave Hansen
2011-01-31 23:20           ` Dave Hansen
2011-02-01  1:43         ` Dave Hansen
2011-02-01  1:43           ` Dave Hansen
2011-02-01 17:17         ` Dave Hansen
2011-02-01 17:17           ` Dave Hansen

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