DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=gmail.com; s=gamma;
        h=date:from:to:cc:subject:message-id:references:mime-version
         :content-type:content-disposition:in-reply-to:user-agent;
        b=d5U+5UFVGVhUpJCHFTtgfyxNNw5w7p8MhSukM9UEsIyz5jEa6SujlJNuDsDFcpg0dM
         NszuX3tbhVztda3n/7kqsEIjYj6C6fxdMSo/OmHoxm/AvxV/15JZq8MuD9r69AcvzbGS
         xs2wbNmZPdjLFIx6reYyH/aMExeBj9RrAKqXk=
Date: Fri, 22 Jan 2010 22:53:04 +0100
From: Jarek Poplawski <jarkao2@gmail.com>
To: Michael Breuer <mbreuer@majjas.com>
Cc: David Miller <davem@davemloft.net>,
       Stephen Hemminger <shemminger@linux-foundation.org>,
       akpm@linux-foundation.org, flyboy@gmail.com,
       linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
       Michael Chan <mchan@broadcom.com>, Don Fry <pcnet32@verizon.net>,
       Francois Romieu <romieu@fr.zoreil.com>,
       Matt Carlson <mcarlson@broadcom.com>
Subject: Re: Hang: 2.6.32.4 sky2/DMAR (was [PATCH] sky2: Fix WARNING: at
 lib/dma-debug.c:902 check_sync)
Message-ID: <20100122215304.GA3105@del.dom.local>
References: <20100120094103.GA6225@ff.dom.local>
 <4B58B217.8030001@majjas.com>
 <20100121204133.GB3085@del.dom.local>
 <4B59E7EB.3050605@majjas.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <4B59E7EB.3050605@majjas.com>
User-Agent: Mutt/1.5.20 (2009-06-14)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1725
Lines: 40

On Fri, Jan 22, 2010 at 01:01:15PM -0500, Michael Breuer wrote:
> Kernel 2.6.32.4 (git) with the following patches applied:
> 
> af_packet.c (tpacket_snd version 3)
> sky2.c pskb_may_pull
> sky2 fix WARNING at lib/dma-debug.c check_sync

I guess, you meant the "sky2.c receive_copy" patch which you tested
earlier, or at least you managed to crash DMAR with that patch
before crashing it with Stephen's "lib/dma-debug.c check_sync" patch,
right?

> Running with CONFIG_DMAR=n, system is stable.
> Running with the exact same source but CONFIG_DMAR=y I get the
> WARNING (see below) after about 36 hours of uptime (has varied from
> about 24 to about 48):
> Smolt profile: http://smolt.fedoraproject.org/show?uuid=pub_bb05c701-1e47-4b3c-9fab-54f520f39d79+
> I'm also attaching dmesg.old (dmesg from the crash).
> 
> Subsequent to this the system watchdog reboots the system (it's hung).
> 
> Of interest: each and every time this has happened the system was
> under heavy RX load (win7 backup to a cifs share hosted on this
> server). Also, there is always a dhcp exchange of some sort
> preceding the event.
> 
> It is possible that the event is re creatable without DMAR enabled,
> but I have been unsuccessful in doing so.

It would be nice to check now if it's re-creatable without the dhcp
exchange yet, or at least dhcp through the switch and the router,
because I suspect there might be something more than a simple drop
on the switch that affects sky2 stability.

Jarek P.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/