Re: [RFC][PATCH] nmi watchdog: handle NMI_IO_APIC on nmi_watchdog

From: Aristeu Rozanski
Date: Wed Oct 22 2008 - 23:36:07 EST


> > > but this stops all NMIs, not just the IO-APIC generated ones, doesnt it?
> > external NMIs would come by LINT1, no?
>
> Correct.
>
> > after reading a lot and talking with Vivek, what I understood was that 8259 is
> > also connected to LINT0, so timer interrupts would be reported both in
> > IOAPIC and on LINT0. LVT0 is being configured on setup_nmi() to generate
> > an NMI. Also, the same timer interrupt would generate an regular interrupt
> > coming from IOAPIC. Clearing the APIC_DM_NMI on LVT0 would disable the
> > NMI delivery, but not the regular interrupt.
> > or am I missing something here?
>
> You are correct. The routing of the 8254 timer interrupt may vary, but
> the NMI watchdog it drives, if supported, always uses the LINT0 input of
> all the local APICs.
thanks

> You seem to be writing in reply to a very old thread -- please make sure
> your concerns are still valid with current code. For example we have an
> implementation of __acpi_nmi_disable() now, which is exactly your proposed
> one.
didn't noticed that, sorry.

--
Aristeu

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