Re: [PATCH RFC] NMI Re-introduce un[set]_nmi_callback

[Don Zickus <dzickus@redhat.com>]

On Thu, Sep 04, 2008 at 05:21:34PM -0400, Vivek Goyal wrote:
> On Thu, Sep 04, 2008 at 09:05:37PM +0000, Mingarelli, Thomas wrote:
> > Ok regarding question #1. The die_notifier works as you mentioned; however, the fact that the watchdog timer ticks also come through as NMIs is a hinderance. Now, when the watchdog timer is configured through the LOCAL_APIC the issue isn't so bad. I think the hpwdt driver handles the NMI coming in because there isn't a flood of timer ticks coming through as in the IOAPIC case.
> 
> Ok, so how does replacing the nmi callback help here? You driver handler
> be still called upon timer ticks. So you will be called on watchdog tick
> whether you are on die chain or you replace nmi handler with nmi callback.
> So watchdog ticks can't be a reason for not being on die chain.

Prarit's patch disabled the timer upon registering a callback to prevent
this case.  The thought was if you have your own handler you could provide
your own watchdog.

Cheers,
Don