Re: [PATCH 2/5] softlockup: make detector be aware of task switch of processes hogging cpu

From: Don Zickus
Date: Mon Aug 18 2014 - 16:38:23 EST


On Mon, Aug 18, 2014 at 09:02:00PM +0200, Ingo Molnar wrote:
>
> * Don Zickus <dzickus@xxxxxxxxxx> wrote:
>
> > > > > So I agree with the motivation of this improvement, but
> > > > > is this implementation namespace-safe?
> > > >
> > > > What namespace are you worried about colliding with? I
> > > > thought softlockup_ would provide the safety?? Maybe I
> > > > am missing something obvious. :-(
> > >
> > > I meant PID namespaces - a PID in itself isn't guaranteed
> > > to be unique across the system.
> >
> > Ah, I don't think we thought about that. Is there a better
> > way to do this? Is there a domain id or something that can
> > be OR'd with the pid?
>
> What is always unique is the task pointer itself. We use pids
> when we interface with user-space - but we don't really do that
> here, right?

No, I don't believe so. Ok, so saving 'current' and comparing that should
be enough, correct?

Cheers,
Don
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