pari as smp benchmark

[Igor Schein <igor@txc.com>]

Hi,

timing of the following command can be used as a decent benchmark of a
system:

echo ';'|gp -qf -p `echo 2^31-1 | bc`

Using this command, I discovered that SMP performance on Linux sucks.
On a dual CPU 1GHz PIII PC running redhat SMP kernel, the execution
time is twice slower if I start this command simultaneously on both
CPUs.  On a 2.4Ghz Xeon PC, it's 5(!) times slower.  Needless to say,
this smp performance degradation doesn't exist on every other platform
I tried.

I would like to report this problem to linux kernel mailing list.  I
am not 100% sure though how to describe this task computationally - is
it L2 cache-intensive ( my guess ), fp-intensive, etc. ?  I've heard
stories of kernel people being difficult, so I would like to present
this problem in the most coincise fashion, so that it's not ignored.
I believe pari users will also benefit if the kernel is fixed. 

So if any is willing to describe in simple terms the nature of this
task, I'd greatly appreciate it.

Thanks

Igor