Mailinglist Archive: opensuse-kernel (32 mails)

[Richard Ems <richard.ems@xxxxxxxxxxxxxxxxx>]

On 02/15/2011 11:29 AM, Dave Howorth wrote:
> Jan Kara wrote:
> > > time perl -e 'use threads; $T=12 ; foreach (1..$T) { $thr[$i++] =
> > > threads->create(sub { printf "I am thread %s\n", threads->tid(); foreach
> > > (1..9e6) { push(@a, sqrt(1234)/sin(1234)) } ; printf "thread %s
> > > finished.\n", threads->tid(); }); } foreach (0..$T-1) { $thr[$_]->join(); }'
>
> what ugly perl :)

I started noticing this problem not with perl but with our CFD
application compiled from C and FORTRAN. There I saw big performance
differences between 2.6.34 and 2.6.37 on openSUSE 11.3. I saw the
differences running on parallel and also in serial.

Then I tried to find an example of this slowdown for others to test
themselves on their machines, that's why I came out with this *simple*
perl test, but I suppose any other language would do it.

I could try a FORTRAN test and share my results.

My last test some days ago was to update one of the openSUSE 11.3 nodes
we have running to openSUSE 11.4 RC 1, and I saw no difference there on
the perl test, so this looks promising again.

I will have to run our own CFD application again on openSUSE 11.4 RC 1
and compare again.

Richard

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Richard Ems       mail: Richard.Ems@xxxxxxxxxxxxxxxxx

Cape Horn Engineering S.L.
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