Re: [patch] enabling APIC and NMI watchdog on UP systems

From: Keith Owens (kaos@ocs.com.au)
Date: Thu Sep 28 2000 - 19:35:49 EST


On Fri, 29 Sep 2000 01:13:06 +0200 (CEST),
Ingo Molnar <mingo@elte.hu> wrote:
>On Fri, 29 Sep 2000, Keith Owens wrote:
>> Using performance counter 1 for NMI conflicts with using the
>> performance counters for tuning. IMHO it is better to default to NMI
>> off for UP so we do not disturb people who are doing performance
>> monitoring. [...]
>
>the number of people experiencing hard lockups, and the importance of
>debugging these (annoying) lockups IMO far outweighs the potential
>inconvenience caused by having to disable the NMI oopser for performance
>tuning.

I did not want to disturb anybody who was already using the performance
counters for tuning so I made NMI for UP optional. You prefer to make
NMI for UP mandatory, change the existing behaviour and force people
who use performance counters to turn off EVNTSEL1 themselves. And they
must remember to reprogram EVNTSEL1 to reactivate NMI after they have
finished tuning.

This is a philosophical difference, not a technical one, we will just
have to agree to disagree. Either way it will be nice to get NMI for
UP into the standard kernel.

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



This archive was generated by hypermail 2b29 : Sat Sep 30 2000 - 21:00:23 EST