Re: [PATCH 2/4] watchdog: introduce arch_touch_nmi_watchdog()

From: Don Zickus
Date: Fri May 26 2017 - 10:05:40 EST


On Fri, May 26, 2017 at 10:31:03AM +1000, Nicholas Piggin wrote:
> On Thu, 25 May 2017 09:55:59 -0400
> Don Zickus <dzickus@xxxxxxxxxx> wrote:
>
> > On Thu, May 25, 2017 at 06:28:54PM +1000, Nicholas Piggin wrote:
> > > For architectures that define HAVE_NMI_WATCHDOG, instead of having
> > > them provide the complete touch_nmi_watchdog() function, just have
> > > them provide arch_touch_nmi_watchdog().
> > >
> > > This gives the generic code more flexibility in implementing this
> > > function, and arch implementations don't miss out on touching the
> > > softlockup watchdog or other generic details.
> >
> > The idea makes sense. I don't think you can have hld_touch_nmi_watchdog
> > defined with arch_touch_nmi_watchdog, so I am wondering if it makes sense to
> > combine them somehow. Though renaming hld_touch_nmi_watchdog to
> > arch_touch_nmi_watchdog sounds odd, I think it mimics the idea.
>
> Yeah I agree it's not quite right, and I think using
> arch_touch_nmi_watchdog would be fine for the hld, which makes sense
> if you think of it as a utility or library function for architectures
> that want a hardlockup watchdog and can use perf for it.

Yeah, if you wouldn't mind trying that. Over the last year it seems there
is a push to make the hld more of a separate thing if folks want to use
perf. I have been trying to tweak it so it can be used in-place of the arch
solution or just use the arch solution. And still retain the same function
calls.

Cheers,
Don

>
> I can change that if you prefer. BTW the 0day picked up another
> Kconfig compile bug, so I'll respin the series and include any changes
> you like.
>
> Thanks,
> Nick