Re: sched_domains and Stream benchmark

[Darren Hart <dvhltc@us.ibm.com>]

On Tue, 2004-04-20 at 11:58, Andi Kleen wrote:
> Darren Hart <dvhltc@us.ibm.com> writes:
> 
> > Andi,
> >
> > You have mentioned the stream benchmark when reporting on the
> > performance of the Opteron NUMA sched-domains scheduler.  I am trying to
> > reproduce your results and am struggling with the benchmark.  Can you
> > rpovide the details of the tests you ran.  Namely your compiler
> > settings, compile command line, and your value of N.  Also I didn't see
> > how to specify the number of threads to run, how did you specify that? 
> > I have a 4 way 1.4 GHz 1MB cache opteron machine with 7 GB of RAM.
> 
> I didn't actually compile them myself; someone sent me executables
> compiled with the PGI compiler.  Maybe your compiler has a different
> runtime and behaves differently? 
> 
> You can find them and my test script that tests everything in 
> ftp://ftp.suse.com/pub/people/ak/bench/stream.tar.gz

Thanks Andi,

I noticed your binary ran with N=2000000 which is only sufficient for a
2 proc 1 MB cache opteron box according to the documentation on the
stream faq.  I also noticed wide variation in results (25% or so) when
running with 4 threads on a 4 proc opteron on linux-2.6.5-mm5.  Can you
provide me with the specs of the system you ran your tests on?

Thanks,

Darren