Re: Lockup after logging out of X

[Andi Kleen <andi@firstfloor.org>]

On Wed, May 09, 2007 at 01:14:59AM +0100, Ken Moffat wrote:
> On Wed, May 09, 2007 at 01:01:34AM +0200, Andi Kleen wrote:
> > 
> > Already known, although it is still unclear what the bug actually is.
> > Can you run with the appended patch please (from Eric Biederman) 
> > and post any backtraces the WARN_ON in there spews out? 
> > 
> > Also do you use swiotlb?
> > 
> > Thanks
> > 
> > -Andi
> > 
>  Had to turn off modules to get it to build.  It half-logged another
> oops, but no backtraces, and SysRq+r does nothing.  Nothing else
> unusual in the log.

Hmm, not good.
> 
> May  9 00:47:12 bluesbreaker gconfd (ken-2833): Resolved address
> "xml:readonly:/etc/gnome/gconf/gconf.xml.defaults" to a read-only
> configuration source at position 2
> May  9 00:52:59 bluesbreaker kernel: [  275.667737] Unable to handle
> kernel paging request at ffff81003b4ac3e8 RIP:
> May  9 00:52:59 bluesbreaker kernel: [  275.667742]
> [<ffffffff8027134a>] fasync_helper+0x52/0xf0
> May  9 00:52:59 bluesbreaker kernel: [  275.667749] PGD 8063 PUD
> 9063 PMD 800000003b4a11e3 BAD
> May  9 00:52:59 bluesbreaker kernel: [  275.667754] Oops: 0009 [1]
> PREEMPT
> May  9 00:54:26 bluesbreaker syslogd 1.4.1: restart.
> May  9 00:54:26 bluesbreaker bootlog: Starting system log daemon...
> [  OK  ]
> 
>  Apparently I do use swiotlb - I didn't know that, and can't see
> where it gets asked in menuconfig, but I can see
> CONFIG_SWIOTLB=y
> 
>  Let me know if there is anything else I can test (probably pm
> tomorrow), otherwise I'll go back to -head.

Yes testing head would be a good idea. It has a different bug fix
from Linus that is supposed to address this too. Unfortunately it is
still not known why it actually breaks; i had hoped to find that out
using the debugging patch

-Andi