Re: nmi watchdog failure on dual Athlon box

From: Maciej W. Rozycki
Date: Tue Sep 28 2004 - 12:11:31 EST


On Tue, 28 Sep 2004, Joerg Sommrey wrote:

> just tried Ingo's "lockupcli" nmi watchdog test - it fails to unlock the
> box.
>
> boot-parm:
> ...nmi_watchdog=2...

The local APIC NMI watchdog has limited capabilities. It may fail to
trigger for certain lockups because there is no available event that would
happen periodically regardless of the CPU state. I can only suspect what
"lockupcli" does (where is it available from, anyway?), but if it runs
"cli; hlt", then the watchdog *will* fail.

> nmi_watchdog=1 has never worked for me (except 2.6.3-mm4).

Too bad. The I/O APIC watchdog triggers regardless of the CPU state and
works as long as the chipset is operational.

Maciej
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