Re: nmi_watchdog suspicious

Maciej W. Rozycki
2008-06-18T16:09:37Z

On Tue, 17 Jun 2008, Cyrill Gorcunov wrote:

> Thanks a lot Maciej for comments! I've marked them. I'm not sure but it seems
> I wrote a bit unclear /my english bad indeed/ ;) I mean - this say 'slipping'
> (ie useless code executions) _was_ before the patch applied. Now it doesn't
> slip on this since we do mention explicitly in which case there should be
> alert counters reset. Other then that - will try to handle your notes. Thanks!

It will happen regardless if touch_nmi_watchdog() is called before the
NMI watchdog has been set up in setup_nmi() or lapic_watchdog_init(). It
may also happen during that window if an NMI is signalled without any NMI
status bits set in the Port B register at 0x61 -- in theory that should
not happen except for a broken configuration, but reality out there seems
to be quite creative about breakage.

Maciej