Measuring impact on interactive tasks

It crossed my mind while load testing some scheduler tunable settings that completely subjective monitoring of X jerkiness perhaps wasn't the most scientific way of measuring the interactive impact of the tunables. I'm no Evil Scientist, but I whipped up a perl script that I think accomplishes something close to capturing those statistics. It captures 1000 samples of what should be a precise .2 second delay (on an idle system it is, with a tiny bit of noise).

Here's the script, along with some output produced while the system was under considerable load (around 13). Would something like this be worth developing further to help rigorously measure the interactive impact of the tunables? Or is there a flaw in the approach? (Jokes about Perl are considered below the belt...)
---scott

# !/usr/bin/perl

use strict;
use warnings;

use Time::HiRes qw/sleep time/;

my %pause = ();

for (my $x = 0; $x < 1000; $x++) {
my $start = time();
sleep(.2);
my $stop = time();
my $elapsed = $stop - $start;

$pause{sprintf('%01.3f', $elapsed)}++;
}

foreach (sort(keys(%pause))) {
print "$_: $pause{$_}\n";
}

exit 0;

Sample output

time ./int_resp_timer.pl

0.192:  1
0.199:  1
0.200:  10
0.201:  201
0.202:  53
0.203:  25
0.204:  22
0.205:  21
0.206:  34
0.207:  29
0.208:  29
0.209:  100
0.210:  250
0.211:  120
0.212:  35
0.213:  16
0.214:  17
0.215:  14
0.216:  9
0.217:  1
0.218:  3
0.219:  3
0.220:  1
0.222:  1
0.233:  1
0.303:  1
0.304:  1
0.385:  1

real    3m28.568s
user    0m0.329s
sys     0m1.260s

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/