From: Ravikiran G T. <ki...@in...> - 2001-12-06 14:05:51
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On Thu, Dec 06, 2001 at 01:07:37PM +0000, Arjan van de Ven wrote: > > > > > > > > How many and which counters were converted for the test you refer to? > > > > > > > Well, I wrote a simple kernel module which just increments a shared global > > counter a million times per processor in parallel, and compared it with > > the statctr which would be incremented a million times per processor in > > parallel.. > > Would you care to point out a statistic in the kernel that is > incremented > more than 10.000 times/second ? (I'm giving you a a factor of 100 of > playroom > here) [One that isn't per-cpu yet of course] Well, as I mentioned in my earlier post, we have performed "micro benchmarking", which does not reflect the actual run time kernel conditions. I guess u gotta take these results with a pinch of salt. But, you cannot deny that there r gonna be a lot of cacheline invalidations, if you use a global counter. Using per-cpu versions is definitely going to improve kernel performance. Kiran -- Ravikiran G Thirumalai <ki...@in...> Linux Technology Center, IBM Software Labs, Bangalore. |