Re: Re: [Xen-users] Xen 4.1.1 crash when manipulating cpupools.

[George Dunlap <george.dunlap@citrix.com>]

On Mon, 2011-11-14 at 09:20 +0000, Juergen Gross wrote:
> On 11/11/2011 10:18 PM, andrewpitman@comcast.net wrote: 
> > Juergen,
> > 
> > It doesn't look like this has been fixed.  I managed to get my 4.1.2
> > server to crash when setting the weight of Domain-0 (running in
> > Pool-0 using credit2) and again when moving some cpus into a new
> > cpupool which was set up to use the credit2 scheduler.
> > 
> 
> Yeah, I could reproduce your problems on my machine.
> 
> George, I see two problems in credit2:
> 
> - when setting the weight of dom0, vcpu_schedule_lock_irq(current)
> will be
>   taken in sched_adjust() of schedule.c and again in csched_dom_cntl()
> of
>   sched_credit2.c resulting in a deadlock.

Yes, this one was recently brought to my attention.  Unfortunately I'm
not sure when I'm going to be able to get to it.  

My big problem is actually testing; I don't have a good way to test
xen-unstable effectively right now.  Juergen, if I were to send you a
prototype patch, could you test it and fix it up if it doesn't work
exactly right?


> 
> - removing a cpu from a cpupool seems not to work for credit2. I
> removed all
>   but cpu 0 from Pool-0 and the dom0 vcpus were all active on cpus
> 1-3. It
>   took some time until they moved to cpu 0 (verified via 'r' hotkey on
> the
>   xen console).
> 
> I tested on xen-4.1-testing cs 23182.
> 
> 
> Juergen
> -- 
> Juergen Gross                 Principal Developer Operating Systems
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