Re: [PATCH -v3] perf, x86: try to handle unknown nmis with running perfctrs

Robert Richter
2010-08-25T10:23:04Z

On 24.08.10 16:27:18, Don Zickus wrote:
> On Tue, Aug 24, 2010 at 11:52:40PM +0400, Cyrill Gorcunov wrote:
> > > I use 2.6.34 atm. Letme try 2.6.36 (which might require some time to recompile).
> > >
> > > -- Cyrill
> >
> > Don, for me it fails with somehow unrelated page handling fault - in
> > reiserfs_evict_inode O_o Fails in __get_cpu_var I suspect might means
> > a problem either in per-cpu allocator itself or we screw pointer somehow.
> > Weird.
>
> I just found out (with the help of the crash utility and Dave A.) that
> Robert's percpu struct nmi clashes with the exception entry point .nmi.
> I only see this problem in 2.6.36, so I am not sure what changed with
> regards to compiler flags to confuse variables with text segments.

I was testing the patches also with CONFIG_LOCKUP_DETECTOR=y without
crashes.

>
> But renaming the percpu struct nmi to nmidon fixed the problem for me (I
> am open to other suggestions :-) ).

Also I was looking at the differences between .35 and tip/perf/urgent
and could not find a namespace collision.

Hmm...

-Robert

--
Advanced Micro Devices, Inc.
Operating System Research Center