On Sat, Jun 29, 2013 at 04:56:30PM -0700, Wedson Almeida Filho wrote:
> On Fri, Jun 28, 2013 at 7:09 AM, Borislav Petkov <b...@alien8.de> wrote:
>
> > Btw, do we have any perf data showing any improvements from this patch?
>
> I wrote a simple test the measures the time it takes to acquire and
> release an uncontended mutex (i.e., we always take the fast path)
> 100k times. I ran it a few times, the original code averages
> 2.743436ms, and the new code averages 2.101098ms, so it's about 23%
> improvement.
Microbenchmark results tend to be misleading in such situations. Rather,
it would be much closer to reality if you traced a real workload like a
simple kernel build, for example, with and without your patch.
I.e., something like
perf stat --repeat 5 ./build-kernel.sh
and take a look at what the perfcouters are saying in both cases.
> I also think the code looks cleaner this way.
No doubt.
--
Regards/Gruss,
Boris.
Sent from a fat crate under my desk. Formatting is fine.
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