lkml.org 
[lkml]   [2010]   [Sep]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] x86: fix duplicate calls of the nmi handler
From
Date
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




\
 
 \ /
  Last update: 2010-09-17 02:15    [from the cache]
©2003-2011 Jasper Spaans