Re: kernel performance update - 2.6.14-rc3

[Nick Piggin]

Arjan van de Ven wrote:
> > dbench is catching some attention.  We just ran it with default
> > parameter.  I don't think default parameter is the right one to use
> > on some of our configurations.  For example, it shows +100% improvement
>
>
> never ever consider dbench a serious benchmark; the thing is you can
> make dbench a lot better very easy; just make the kernel run one thread
> at a time until completion. dbench really gives very variable results,
> but it is not really possible to say if +100% or -100% is an improvement
> or a degredation for real life. So please just don't run it, or at least
> don't interpret the results in a "higher is better" way.

As a disk IO performance benchmark you are absolutely right.

Some people like using it to test VM scalability and throughput
if it is being used on tmpfs. In that case the results are
generally more stable.

--
SUSE Labs, Novell Inc.

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