lkml.org 
[lkml]   [2011]   [Aug]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [V3][PATCH 0/6] x86, nmi: new NMI handling routines
On Fri, Aug 26, 2011 at 11:44:57AM +0200, Peter Zijlstra wrote:
> On Thu, 2011-08-25 at 12:45 -0400, Don Zickus wrote:
> > I spent some time hacking and came up with this patch. I tested it on my
> > core2quad machine trying to enable all the NMI handler I could, mainly
> > perf and kgdb (and oprofile too when perf was disabled). Everything seems
> > to work correctly. If people are ok with this approach, I'll try and test
> > this on more machines.
>
> Right, code looks OK, the only worry that remains is overhead, always
> running all handlers must cost..

Yeah nothing is free. My only counter argument is I removed the case
statements in the handlers, so it speeds things up a tiny bit. Also most
machines only seem to have perf and the arch_backtrace handler registered,
with modern intel boxes probably registering the ghes handler too.

There really isn't much there, at least currently. I would break up the
handler more if I knew a quicker way to distinguish between something like
a self-IPI NMI vs. an on-chip NMI like perf. Then again those NMIs
probably aren't latched differently unlike the external one sitting in the
IOAPIC(??).

Cheers,
Don


\
 
 \ /
  Last update: 2011-08-26 16:43    [W:0.224 / U:0.032 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site