Messages in this thread | | | Date | Fri, 6 Jul 2007 19:43:15 -0400 | From | Mathieu Desnoyers <> | Subject | Re: [patch 10/10] Scheduler profiling - Use immediate values |
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* 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/
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