Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755356AbZIULHj (ORCPT ); Mon, 21 Sep 2009 07:07:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753322AbZIULHi (ORCPT ); Mon, 21 Sep 2009 07:07:38 -0400 Received: from mail.gmx.net ([213.165.64.20]:54983 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1755068AbZIULHg (ORCPT ); Mon, 21 Sep 2009 07:07:36 -0400 X-Authenticated: #25574588 X-Provags-ID: V01U2FsdGVkX18f4SkXbM8fxfQddb9Viec3WFeaTtbFWlMk6f3ml8 /c8zYD2v+GfjWe Date: Mon, 21 Sep 2009 23:25:53 +1200 From: Johannes Buchner To: linux-kernel@vger.kernel.org Subject: Influence of optimization level, preemption and scheduler on boot time Message-Id: <20090921232553.c97560c7.buchner.johannes@gmx.at> X-Mailer: Sylpheed 2.6.0 (GTK+ 2.16.6; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: multipart/signed; protocol="application/pgp-signature"; micalg="PGP-SHA1"; boundary="Signature=_Mon__21_Sep_2009_23_25_53_+1200_+oElbJ3WDygdTJ5Y" X-Y-GMX-Trusted: 0 X-FuHaFi: 0.64 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1591 Lines: 49 --Signature=_Mon__21_Sep_2009_23_25_53_+1200_+oElbJ3WDygdTJ5Y Content-Type: text/plain; charset=ISO-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi all. I measured the kernel (and system) boot times while varying the parameters: - Optimization level: -Os, -O2 and also -O3 - Preemptive model - Scheduler: CFQ, Anticipatory, Deadline, Noop My conclusion was that the optimization level and the preemptive model had no significant influence on speed. CFQ let my system boot several seconds faster than the other schedulers. Graphs can be found at: http://johannes.jakeapp.com/blog/?p=3D913 This conclusion may not be true for all situations, but I found it interesting that the optimization level is so irrelevant. Cheers, Johannes (I am not subscribed to the list.) --=20 Emails k=F6nnen ge=E4ndert, gef=E4lscht und eingesehen werden. Signiere oder versch=FCssele deine Mails mit GPG. http://web.student.tuwien.ac.at/~e0625457/pgp.html --Signature=_Mon__21_Sep_2009_23_25_53_+1200_+oElbJ3WDygdTJ5Y Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.11 (GNU/Linux) iEYEARECAAYFAkq3YsgACgkQ7X1+MfqVcr3/AACfWAelEgeezRgEr+RcFK/j5LVG rmUAnjOhpx9RL8scOrfa0BBb71OlAgNs =EGW8 -----END PGP SIGNATURE----- --Signature=_Mon__21_Sep_2009_23_25_53_+1200_+oElbJ3WDygdTJ5Y-- -- 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/