Re: [PATCH v2 0/6] arm64: provide pseudo NMI with GICv3

[Julien Thierry]

On 29/04/18 07:37, Joel Fernandes wrote:
> On Wed, Jan 17, 2018 at 4:10 AM, Julien Thierry <julien.thierry@xxxxxxx> wrote:
> > Hi,
> >
> > On 17/01/18 11:54, Julien Thierry wrote:
> > > This series is a continuation of the work started by Daniel [1]. The goal
> > > is to use GICv3 interrupt priorities to simulate an NMI.
> >
> >
> > I have submitted a separate series making use of this feature for the ARM
> > PMUv3 interrupt [1].
>
> I guess the hard lockup detector using NMI could be a nice next step
> to see how well it works with lock up detection. That's the main
> usecase for my interest. However, perf profiling is also a strong one.

From my understanding, Linux's hardlockup detector already uses the ARM 
PMU interrupt to check whether some task is stuck. I haven't looked at 
the details of the implementation yet, but in theory having the PMU 
interrupt as NMI should make the hard lockup detector use the NMI.

When I do the v3, I'll have a look at this to check whether the 
hardlockup detector works fine when using NMI.

Cheers,

--
Julien Thierry