Re: [PATCH 1/2] x86_64 nmi_watchdog: Make check_nmi_watchdog static

[Andi Kleen]

On Tuesday 04 October 2005 17:26, Eric W. Biederman wrote:
> Andi Kleen <ak@xxxxxxx> writes:
> > On Tuesday 04 October 2005 17:11, Eric W. Biederman wrote:
> >> By using a late_initcall as i386 does we don't need to call
> >> check_nmi_watchdog manually after SMP startup, and we don't
> >> need different code paths for SMP and non SMP.
> >>
> >> This paves the way for moving apic initialization into init_IRQ,
> >> where it belongs.
> >
> > I don't like it. I want to see a clear message in the log when
> > the NMI watchdog doesn't work and with your patch that comes too late.
>
> Why is it to late?

It's after too much of the boot. e.g. consider analyzing log with a boot hang.
It's important to know if the NMI watchdog runs or not. For that it is
best when the test of it happens as early as possible.

>
> > -Andi (who has rejected similar patches before)
>
> Would it be more appropriate to make this a per cpu check?

That would be fine as long as it's as early as possible.
But I suspect you'll always need special cases for the BP
because it needs the timer running first.

-Andi
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