Re: [RFC] x86, NMI, Treat unknown NMI as hardware error

From: Cyrill Gorcunov
Date: Sun May 15 2011 - 02:35:19 EST


On 05/15/2011 04:06 AM, huang ying wrote:
...
>>
>> yes, is not good. But at least we *must* provide a way to turn this new feature off
>> via command line I think. One of a reason for me is perf unknown nmis (at moment we seems
>> to have captured and cured all parasite NMIs sources but there is no guarantee we wont
>> meet them in future due to some code change or whatever). And bloating trap.c with
>> new if()'s is not that good I guess, that is why I asked if there a way to do all the
>> work via notifiers ;)
>
> Yes. We should consider about perf unknown NMI issues. But compared
> with pushing all magic to user, I think the better way is to have a
> better default behavior in kernel. For example, we can turn off
> unknown NMI as hwerr logic temporarily if there are more than 1 perf
> NMI events in action. Is that reasonable?

I'm personally fine even if it's enabled by default, only worried to have
an option to disable hwerr from boot line.

>
> And, I am not a big fan of notifiers, that makes code hard to be
> understood. If you have concerns about the size of traps.c, we can
> move all NMI logic to a new file.

Ying, the concern is rather related to the code scheme in general. Since
we have notifiers I think the better way to be consistent here and use
hwerr notifier too. But it's IMHO ;)

>
> Best Regards,
> Huang Ying

--
Cyrill
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