Re: soft lockup detector & virtualisation

[john stultz]

On Thu, Feb 16, 2012 at 3:15 PM, Dave Jones <davej@xxxxxxxxxx> wrote:
> Lately I've noticed quite a few soft lockup bugs being reported.
> In many of them, they're coming from inside virtual guests.
>
> Is the softlockup detector fundamentally broken in this situation ?
>
> If the host doesn't schedule the guest for whatever reason,
> or the user suspends the VM and resumes it later ?
>
> Here's the most recent example:
> https://bugzilla.redhat.com/attachment.cgi?id=563767
>
> In many of these, the code where it's "stuck" isn't anything
> special, which is why I think the guest just hasn't had a
> timeslice in 185 seconds.
>
> Is there some way we can perhaps detect we're running virtualised,
> and disable the detector automatically ?

I think Eric's work (See "Add check for suspended vm in softlockup
detector" sent out today) tries to address this issue.

thanks
-john
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