Re: [patch 10/10] Scheduler profiling - Use immediate values

From: Adrian Bunk
Date: Fri Jul 06 2007 - 19:28:34 EST


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.

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

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