Re: Catching NForce2 lockup with NMI watchdog

From: Maciej W. Rozycki
Date: Tue Dec 16 2003 - 11:52:02 EST


On Tue, 16 Dec 2003, Richard B. Johnson wrote:

> Although I haven't looked at recent source-code, with APIC, the
> problem is even simpler. If you booted with APIC, just set
> the global "using_apic_timer" to zero and, voila`, timer-ticks
> stop.

Except we are writing of the 8254 timer, not the local APIC one...

> ...the machine will lock-up forever because without that timer,
> there will be no preemption. Once a CPU-hog gets the CPU, only
> and interrupt can get it away.

And the 8254 timer isn't used for preemption when local APICs are used,
so disabling it won't break the whole system, only the timekeeping.

--
+ Maciej W. Rozycki, Technical University of Gdansk, Poland +
+--------------------------------------------------------------+
+ e-mail: macro@xxxxxxxxxxxxx, PGP key available +
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