Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 26 Dec 2002 20:30:56 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 26 Dec 2002 20:30:56 -0500 Received: from dsl2-09018-wi.customer.centurytel.net ([209.206.215.38]:59553 "HELO thomasons.org") by vger.kernel.org with SMTP id convert rfc822-to-8bit; Thu, 26 Dec 2002 20:30:54 -0500 Content-Type: text/plain; charset="us-ascii" From: scott thomason Reply-To: scott@thomasons.org To: Linux Kernel Mailing List Subject: Measuring impact on interactive tasks Date: Thu, 26 Dec 2002 19:39:09 -0600 User-Agent: KMail/1.4.3 MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Message-Id: <200212261939.09792.scott@thomasons.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1779 Lines: 82 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 majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/