Messages in this thread | | | Subject | Re: [PATCH] x86: fix duplicate calls of the nmi handler | From | Huang Ying <> | Date | Fri, 17 Sep 2010 08:13:16 +0800 |
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On Fri, 2010-09-17 at 01:42 +0800, Peter Zijlstra wrote: > On Fri, 2010-09-10 at 17:56 +0200, Robert Richter wrote: > > The commit: > > > > e40b172 x86: Move notify_die from nmi.c to traps.c > > > > moved the nmi handler call to default_do_nmi(). DIE_NMI_IPI and > > DIE_NMI are called subsequently now. If the return code is > > !NOTIFY_STOP, then the handlers are called twice. This patch fixes > > this. > > What is this NMI_IPI thing, and why do we bother? > > If the hardware reason thin can discriminate between IPI and other NMIs > we should never call both chains, if it cannot, why do we have 2 chains? > > In any case, I don't think perf/oprofile/etc,. should use NMI_IPI, that > doesn't really make sense. > > Or am I totally confused about things here?
Please take a look at my recent patch that rewrites the NMI handler. Where NMI are divided into two types. CPU specific NMI are processed firstly as DIE_NMI_IPI, and non-CPU specific NMI are processed as DIE_NMI.
CPU specific NMIs include perf event, oprofile, crash, etc. They can be processed on specific CPU only.
non-CPU specific NMIs include SERR and IOCHK NMI (via checking port 0x61) and APEI GHES NMI. They can be processed on any CPU.
Best Regards, Huang Ying
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