That sounds pretty reasonable; it might be interesting if it also touched
quite a bit of memory each iteration too.
Andrew
--On Thursday, December 26, 2002 19:39:09 -0600 scott thomason
<scott@thomasons.org> wrote:
> 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
>
> -
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