Re: benh performance problem

On Thu, 2004-02-05 at 21:09, Mikolaj Krzewicki wrote:

the benchmark i used shows a speedup back to the values i'm used to.
The benchmark itself is an octave script the execution time of which i
tested with different kernels under similar circumstances, so here are
the details:

2.6.1-benh1, HZ=1000: timing=36.5s
2.6.1-benh1, HZ=100 : timing=32s

this is with X running and a lot more processes(not running).
the weird thing is it executes slightly faster (on average) with
pbbuttonsd off.
The machine is g3 500 ibook, the octave script is:

   tic;
     a = abs(randn(1500, 1500)/10);
     b = a';
     c= a*b;
     a = reshape(b, 750, 3000);
     b = a';
   timing=toc;

so lots of system calls and cache flushing is in order.

Mikolaj.

Well, I don't knwo what the above means, I don't talk that language
anyway :)

The fact that pbbuttons makes a difference makes me think the
interrupt handling is taking way too much time on your setup,
and pbbuttons is loading the machine with PMU interrupts...

Not sure if I can fix any of this at this point without doing a
major rewrite of the exception handling code, I suspect those
CPUs don't like running in real mode and our exception handling
happens mostly in that mode in ppc32...

Ben.


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