Re: [PATCH] watchdog: hpwdt: Remove spinlock acquire and BIOS calls from NMI context

Jerry Hoemann
2018-02-15T17:44:53Z

On Thu, Feb 15, 2018 at 12:17:04AM +0100, Ingo Molnar wrote:
>
> * Jerry Hoemann <jerry.hoemann@hpe.com> wrote:
>
> >
> > Ingo,
> >
> > I have a patch set under review that brings hpwdt into compliance
> > with the watchdog core.
> >
> > One of the changes removes the callback into firmware in hpwdt_pretimeout
> > and its associated spinlock.
> >
> > https://lkml.org/lkml/2018/2/12/30
>
> drivers/watchdog/hpwdt.c | 490 +----------------------------------------------
> 1 file changed, 8 insertions(+), 482 deletions(-)
>
> Very nice, and this should solve all the NMI handling complications!
>
> > I will add you to the CC list of the next version of the set.
>
> Thanks!
>
> Ingo

Ingo,

Is your desire to remove of the firmware callback/spinlock in hpwdt_pretimeout
related to David Woodhouse patch set:

https://lkml.org/lkml/2018/2/14/305 ?

Which I think are to mitigate performance issues resulting from the
changes to address the specter/meltdown?

Any there other changes to hpwdt needed related to this work?

Thanks

Jerry

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Jerry Hoemann Software Engineer Hewlett Packard Enterprise
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