Re: BUG: soft lockup - CPU#0 stuck for 61s!

["Andres Lagar-Cavilla" <andres@lagarcavilla.org>]

> On Thu, 2012-03-29 at 16:43 +0100, Andres Lagar-Cavilla wrote:
>> Ian,
>>
>> I came across the subject line on a 96GB server with over 85 VMs
>> running.
>> Completely frozen and unresponsive, qemu-dm processes hung on event
>> channels. I'm using the XenServer 6.0 dom0 kernel on top of the
>> xen-unstable tip hypervisor.
>>
>> I believe you solved the issue backporting some event channel patches to
>> the 2.6.32 kernel, as described in this thread
>> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=638172
>>
>> I am missing a bit of context in order to retrieve the patches and apply
>> them to my setup. What trees are involved here?
>
> This was a backport to a 2.6.32 pvops kernel. The Debian Squeeze kernel
> is a snapshot from Jeremy's xen.git at some point in the past.
> drivers/xen/events.c is pretty different to the classic-Xen kernels like
> XenServers.
>
>>  I'm looking in particular
>> for "multiple fixes to PIRQ event channel handling" and friends, but I
>> don't have commit identifiers, nor a tree URL (neither I am too sure
>> what
>> changesets from which upstream tree do the backports aggregate).
>
> I think the pirq stuff was because the aforementioned snapshot happened
> to be taken in the middle of a transition in how pirqs were handled, so
> I was back porting the remainder.
>
> Anyway, if you want them you  can find them in the Debian source
> package, they are listed in debian/patches/series/40-extra, the paths
> there are relative to debian/patches.
>
> Also, I think (but I'm not 100% sure any more) that these patches
> correspond to this branch in my xenbits tree:
>
>   git://xenbits.xen.org/people/ianc/linux-2.6.git debian/squeeze/evtchn
>
Thanks very much, this will get me going
Andres

> Ian
>
>