Messages in this thread | | | Date | Tue, 16 Dec 2003 11:44:25 -0500 (EST) | From | "Richard B. Johnson" <> | Subject | Re: Catching NForce2 lockup with NMI watchdog |
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On Tue, 16 Dec 2003, Maciej W. Rozycki wrote:
> On Tue, 16 Dec 2003, Richard B. Johnson wrote: > > > Masking OFF the timer channel 0 in the interrupt controller > > is probably the easiest thing to do. The port is read-write, > > and the OCW default to having it accessible. > > Note we are writing about configurations involving an I/O APIC, so things > are not that easy -- the 8254 timer IRQ may be wired in different ways. > > -- > + Maciej W. Rozycki, Technical University of Gdansk, Poland + > +--------------------------------------------------------------+ > + e-mail: macro@ds2.pg.gda.pl, PGP key available +
Well if I was trying to isolate a problem, I would make it that easy. You boot the machine in its simplist configuration and work "up" from there.
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.
Any any event, the caller needs to know that if there is any code executing anywhere that does the equivalent of
for(;;) ;
...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.
Cheers, Dick Johnson Penguin : Linux version 2.4.22 on an i686 machine (797.90 BogoMips). Note 96.31% of all statistics are fiction.
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