Re: [PATCH 0/5] More NMI IPI enablement work

[Nicholas Piggin <npiggin@gmail.com>]

On Thu, 21 Sep 2017 21:10:42 +1000
Michael Ellerman <mpe@ellerman.id.au> wrote:

> Nicholas Piggin <npiggin@gmail.com> writes:
> 
> > Hi,
> >
> > Here is the NMI IPI enablement for powernv, which requires
> > supported firmware and hardware:
> >
> > https://lists.ozlabs.org/pipermail/skiboot/2017-September/009111.html
> >
> > And some preceeding patches that fix issues I ran into when
> > testing it.  
> 
> Are any of these critical such that I should pick them up for 4.14 or
> earlier?

Good point, yes. The hardlockup watchdog now does SMP cross-checking,
so it can blow up when you stay in xmon for about 10 seconds since the
new watchdog was merged. We want patches 3-4 for that.

Patch 1 is not really required, I only ran into it when I tried making
smp_send_stop use the NMI IPI, which we are not doing just yet. That
being said, the watchdog code is new, so probably doesn't hurt to put
in 4.14.

Patch 3 makes all-cpus backtraces a bit more concise. Less critical.

The system reset stuff I guess we'll want to backport for distros, so
4.14 might be reasonable not sure.

Actually patch 5 before you merge it I should remove the DD1
workaround too because we're not supporting that in OPAL anymore.

Thanks,
Nick