Re: A costing analysis tool

On Fri, Oct 14, 2005 at 03:34:43PM -0500, Kevin Grittner wrote:
> of the two times as a reliability factor.  Unfortunately, that
> means doubling the number of cache flushes, which is likely
> to be the most time-consuming part of running the tests.  On
> the bright side, we would capture the top level runtimes you
> want.

Actually, if you shut down the database and run this bit of code with a
high enough number you should have a nicely cleaned cache.

int main(int argc, char *argv[]) {   if (!calloc(atoi(argv[1]), 1024*1024)) { printf("Error allocating memory.\n"); }
}

Running that on a dual Opteron (842's, I think) gives:
decibel@fritz.1[16:35]~:10>time ./a.out 3300
3.142u 8.940s 0:40.62 29.7%     5+4302498k 0+0io 2pf+0w

That was on http://stats.distributed.net and resulted in about 100MB
being paged to disk. With 3000 it only took 20 seconds, but might not
have cleared 100% of memory.
-- 
Jim C. Nasby, Sr. Engineering Consultant      jnasby@pervasive.com
Pervasive Software      http://pervasive.com    work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf       cell: 512-569-9461