lkml.org 
[lkml]   [2007]   [Jul]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [patch 10/10] Scheduler profiling - Use immediate values
* Adrian Bunk (bunk@stusta.de) wrote:
> On Fri, Jul 06, 2007 at 06:14:10PM -0400, Chuck Ebbert wrote:
> > On 07/06/2007 07:44 AM, Andi Kleen wrote:
> > > I think the optimization is a good idea, although i dislike it
> > > that it is complicated for the dynamic markers. If it was just
> > > static it would be much simpler.
> >
> > Another thing to consider is that there might be hundreds of these
> > probes/tracepoints active in an instrumented kernel. The overhead
> > adds up fast, so the gain may be worth all the pain.
>
> Only if you want to squeeze the last bit of performance out of
> _debugging_ functionality.
>
> You avoid all the pain if you simply don't use debugging functionality
> on production systems.
>

Adrian,

Please have a look at my markers posts, especially:

http://www.ussg.iu.edu/hypermail/linux/kernel/0707.0/0669.html

And also look into OLS 2007 proceedings for Martin Bligh's paper on
Debugging Google sized clusters. It basically makes the case for adding
functionnality to debug _user space_ problems on production systems that
can be turned on dynamically.

Mathieu

> cu
> Adrian
>
> --
>
> "Is there not promise of rain?" Ling Tan asked suddenly out
> of the darkness. There had been need of rain for many days.
> "Only a promise," Lao Er said.
> Pearl S. Buck - Dragon Seed
>

--
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-07-07 01:45    [W:0.125 / U:0.016 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site