RE: [Xen-devel] Timer going backwards and Unable to handle kernel NULLpointer

["Ian Pratt" <Ian.Pratt@xxxxxxxxxxxx>]

> I've got a Thunder K8SRE with two dual core Opteron processors and
> eight 1 GB SDRAM sticks in it.
> Booting in to SMP mode resulted in this:
> 
> May 16 00:43:37 weebl kernel: Timer ISR/3: Time went backwards:
> delta=-12967620 delta_cpu=217015619 shadow=46263756493 off=423276508
> processed=46700000000 cpu_processed=46470016761
> May 16 00:43:37 weebl kernel:  0: 46680000000
> May 16 00:43:37 weebl kernel:  1: 46700016761
> May 16 00:43:37 weebl kernel:  2: 45670016761
> May 16 00:43:37 weebl kernel:  3: 46470016761

The only time I've seen this is on a system that was overheating and
bouncing in and out of thermal throttling. Any chance that could be
happening here?

> May 16 06:28:35 weebl kernel: Call Trace:
> <ffffffff8011a275>{mm_unpin+427}
> <ffffffff8011a4a4>{_arch_exit_mmap+476}
> May 16 06:28:35 weebl kernel:
> <ffffffff8014fedd>{generic_file_aio_read+52}
> <ffffffff801724a6>{do_sync_read+199}
> May 16 06:28:35 weebl kernel:        <ffffffff801612d2>{exit_mmap+34}
> <ffffffff80128e05>{mmput+40}
> May 16 06:28:35 weebl kernel:

That's a nasty crash. There were some cleanups in this area in Xen 3.1,
but I don't think it was to address a specific crash like this. Might be
worth trying 3.1 on the machine.


Best,
Ian



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel