Re: [PATCH/RFC] stop_machine: make stop_machine_run more virtualization friendly

From: Christian Borntraeger
Date: Thu May 08 2008 - 10:41:47 EST


Am Donnerstag, 8. Mai 2008 schrieb Jeremy Fitzhardinge:
> Christian Borntraeger wrote:
> > On kvm I have seen some rare hangs in stop_machine when I used more guest
> > cpus than hosts cpus. e.g. 32 guest cpus on 1 host cpu triggered the
> > hang quite often. I could also reproduce the problem on a 4 way z/VM host
with
> > a 64 way guest.
> >
>
> I think that's one of those "don't do that then" cases ;)

I really like 64 guest cpus as a good testcase for all kind of things.

>
> I think x86 (at least) is now using ticket locks, which is fair. Which
> kernel are you seeing this problem on?

Sorry, forgot to mention. Its kvm.git from 2 days ago on s390.

--
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/