Re: [patch] serial console vs NMI watchdog

From: Keith Owens (kaos@ocs.com.au)
Date: Sun Mar 11 2001 - 02:52:02 EST


On Sun, 11 Mar 2001 08:44:24 +0100 (CET),
Ingo Molnar <mingo@elte.hu> wrote:
>Andrew,
>
>your patch looks too complex, and doesnt cover the case of the serial
>driver deadlocking. Why not add a "touch_nmi_watchdog_counter()" function
>that just changes last_irq_sums instead of adding locking? This way
>deadlocks will be caught in the serial code too. (because touch_nmi() will
>only "postpone" the NMI watchdog lockup event, not disable it.)

kdb has to completely disable the nmi counter while it is in control.
All interrupts are disabled, all but one cpus are spinning, the control
cpu does busy wait while it polls the input devices. With that model
there is no alternative to a complete disable.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Thu Mar 15 2001 - 21:00:12 EST