How to reproduce: Re: Only 70% of theoretical peak performance on FreeBSD 8/amd64, Corei7 920

[Adam Vande More]

On Wed, Apr 14, 2010 at 11:51 AM, Andriy Gapon <avg at freebsd.org> wrote:

> on 14/04/2010 19:45 Adam Vande More said the following:
> >
> > also if I run cpuset on the dgemm then the utilization is basically at
> > the theoretical max for one core so at least that part is working.
>
> You can also try procstat -t <pid> to find out thread IDs and cpuset -t to
> pin the
> threads to the cores.
>

it gets to around 90% doing that.

time : 103.617271 or 27.140992
Mflops : 47172.925449
n: 4100
time : 113.910669 or 30.520677
Mflops : 45174.496186
n: 4200
time : 121.880695 or 32.068070
Mflops : 46217.711013
n: 4300

tried a couple of different thread orders but didn't seem to make a
difference.

galacticdominator% procstat -t 1922
  PID    TID COMM             TDNAME           CPU  PRI STATE   WCHAN
 1922 100092 dgemm            initial thread     0  190 run     -
 1922 100268 dgemm            -                  1  190 run     -
 1922 100270 dgemm            -                  1  191 run     -
 1922 100272 dgemm            -                  3  190 run     -
 1922 100273 dgemm            -                  2  191 run     -
 1922 100274 dgemm            -                  2  191 run     -
 1922 100282 dgemm            -                  0  190 run     -
 1922 100283 dgemm            -                  3  190 run     -

galacticdominator% cpuset -t 100092 -l 0
galacticdominator% cpuset -t 100268 -l 1
galacticdominator% cpuset -t 100270 -l 2
galacticdominator% cpuset -t 100272 -l 3
galacticdominator% cpuset -t 100273 -l 0
galacticdominator% cpuset -t 100274 -l 1
galacticdominator% cpuset -t 100282 -l 2
galacticdominator% cpuset -t 100283 -l 3


galacticdominator% cpuset -t 100092 -l 0
galacticdominator% cpuset -t 100268 -l 0
galacticdominator% cpuset -t 100270 -l 1
galacticdominator% cpuset -t 100272 -l 1
galacticdominator% cpuset -t 100273 -l 2
galacticdominator% cpuset -t 100274 -l 2
galacticdominator% cpuset -t 100282 -l 3
galacticdominator% cpuset -t 100283 -l 3


This is from the second set:

time : 150.348850 or 40.488350
Mflops : 45022.951141
n: 4600
time : 161.968982 or 43.589618
Mflops : 44669.884500
n: 4700

Since this is a full fledged desktop environment, 90% utilization seems
pretty good.  I'm no expert Andriy, but it seems like if gotoblas
implemented some of the FreeBSD optimizations then we'd be in the same
ballpark.


-- 
Adam Vande More