Messages in this thread | | | Date | Fri, 03 Jan 2003 01:33:55 -0800 | From | Andrew Morton <> | Subject | Re: [BENCHMARK] Lmbench 2.5.54-mm2 (impressive improvements) |
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Aniruddha M Marathe wrote: > > Here is a comparison of results of 2.5.54 with mm2 and 2.5.54.
I'm sorry, but all you are doing with these tests is discrediting lmbench, AIM9, tiobench and unixbench. There really is nothing in these patches which can account for the changes which you are observing.
Possibly, it is all caused by cache colouring effects - the physical addresses at which critical kernel and userspace text and data happen to end up.
I'd suggest that you look for more complex tests. There's a decent list at http://lbs.sourceforge.net/, but even those are rather microscopic.
If you have time, things like the osdl dbt1 test, http://osdb.sourceforge.net/ and the commercial benchmarks would be more interesting.
Or cook up some of your own: it's not hard. Just think of some time-consuming operation which we perform on a daily basis and measure it. Script the startup and shutdown of X11 applications. rsync. sendmail. cvs.
Mixed workloads are interesting and real world: run tiobench or dbench or qsbench or whatever while trying to do something else, see how long "something else" takes.
It is these sorts of things which will find areas of weakness which can be addressed in this phase of kernel development.
The teeny little microbenchmarks are telling us that the rmap overhead hurts, that the uninlining of copy_*_user may have been a bad idea, that the addition of AIO has cost a little and that the complexity which yielded large improvements in readv(), writev() and SMP throughput were not free. All of this is already known. - 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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