Re: 2 CPUs and ps/top -- question

[Ossama Othman <othman@astrosun.tn.cornell.edu>]

I found an answer to my question from one of my colleagues.  This
seems like a good thing to know so I'll post it in case anyone is
interested.  Here is he how checks to see how well his SMPing is working:

(incidentally, these are benchmarks for a Debian 2.0 system running kernel
2.0.35 on a dual PII-333)

Basically, we make Perl count to one million in two seperate processes,
simultaneously.  For two processes on a two processor machine, the CPU
usage should be close to 100% for each process, assuming that the machine 
is lightly loaded, meaning that each process is running on a seperate CPU
since it isn't possible to have 200% usage on one CPU.  :)

time perl -e 'for($i=0;$i<10000000;$i++){}' &
*** Results
1.200u 11.550s 0:12.78 99.7%    0+0k 0+0io 227pf+0w

time perl -e 'for($i=0;$i<10000000;$i++){}' & \
time perl -e 'for($i=0;$i<10000000;$i++){}' &
*** Results
0.000u 12.750s 0:12.81 99.5%    0+0k 0+0io 227pf+0w
12.730u 0.070s 0:12.91 99.1%    0+0k 0+0io 227pf+0w

time perl -e 'for($i=0;$i<10000000;$i++){}' & \
time perl -e 'for($i=0;$i<10000000;$i++){}' & \
time perl -e 'for($i=0;$i<10000000;$i++){}' & \
time perl -e 'for($i=0;$i<10000000;$i++){}' &
*** Results
0.000u 12.750s 0:25.26 50.4%    0+0k 0+0io 227pf+0w
12.130u 0.640s 0:25.28 50.5%    0+0k 0+0io 227pf+0w
0.690u 12.070s 0:25.58 49.8%    0+0k 0+0io 227pf+0w
12.720u 0.080s 0:25.58 50.0%    0+0k 0+0io 227pf+0w

-Ossama


--  
Unsubscribe?  mail -s unsubscribe debian-user-request@lists.debian.org < /dev/null