Re: Hang: 2.6.32.4 sky2/DMAR (was [PATCH] sky2: Fix WARNING: atlib/dma-debug.c:902 check_sync)

[Jarek Poplawski]

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@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/