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Subject: Re: [PATCH] x86: fix duplicate calls of the nmi handler
From: Huang Ying <ying.huang@intel.com>
To: Peter Zijlstra <peterz@infradead.org>
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Date: Fri, 17 Sep 2010 16:47:27 +0800
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On Fri, 2010-09-17 at 15:52 +0800, Peter Zijlstra wrote:
> On Fri, 2010-09-17 at 08:13 +0800, Huang Ying wrote:
> 
> > Please take a look at my recent patch that rewrites the NMI handler.
> 
> (Link would have been useful)

http://lkml.org/lkml/2010/9/9/575

> > 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.
> 
> OK, and you can discriminate between these two by means of that reason
> port? Still I think NMI_IPI is a terrible name for that.

In my patches, DIE_NMI_IPI go firstly, then DIE_NMI follows. NMI reason
is not used for that.

I don't know the history of naming too. But I think the name may come
from apic->send_IPI(mask, NMI_VECTOR). Which is used by crash_kexec,

crash_kexec
  machine_crash_shutdown
    kdump_nmi_shootdown_cpus
      nmi_shootdown_cpus
        smp_send_nmi_allbutself

Best Regards,
Huang Ying