Re: [PATCH -tip] perf, x86: fix unknown NMIs on a Pentium4 box

From: Cyrill Gorcunov
Date: Thu Apr 14 2011 - 16:19:02 EST

On 04/15/2011 12:05 AM, Cyrill Gorcunov wrote:
>> I don't think this patch will work. It would make sense if the unmasking
>> happened _after_ the "if (!handled)" path, but that is not the path Ingo
>> wanted for v1.
> This thing happened if inflight nmi reaches the system and note that inflight
> NMI comes from perf and masks lvt entry, it has nothing to do with "handled" but
> rather the _fact_ that NMI reached apic via LVTPC and as result -- masked it.
> Don, I might be missin something, brain is slowly going to sleep :)

Seems I'm wrong in this assumption, otherwise when this mechanism was
introduced for first time every in-flight nmi catched would block further
perf activity.

>> Cheers,
>> Don

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