From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756588AbYHQWPp (ORCPT ); Sun, 17 Aug 2008 18:15:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752411AbYHQWPh (ORCPT ); Sun, 17 Aug 2008 18:15:37 -0400 Received: from ms01.sssup.it ([193.205.80.99]:40625 "EHLO sssup.it" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751855AbYHQWPg (ORCPT ); Sun, 17 Aug 2008 18:15:36 -0400 Subject: Re: SCHED_FIFO and SCHED_RR broken by cfs From: Dario Faggioli To: Stefani Seibold Cc: Peter Zijlstra , linux-kernel@vger.kernel.org, mingo@redhat.com In-Reply-To: <1218922190.3747.6.camel@matrix> References: <1218880552.11912.9.camel@matrix> <1218898413.10800.252.camel@twins> <1218922190.3747.6.camel@matrix> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-7JOx75FXGPoxnNgO/obs" Date: Mon, 18 Aug 2008 00:15:26 +0200 Message-Id: <1219011326.25992.19.camel@Palanthas> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-7JOx75FXGPoxnNgO/obs Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Sat, 2008-08-16 at 23:29 +0200, Stefani Seibold wrote: > After disabling kernel support for "Group CPU scheduler" and applying > 'echo -1 > /proc/sys/kernel/sched_rt_runtime_us' the behaviour is as > expected. >=20 > chrt -f 99 ./a.out >=20 > average:13 usec > min. jitter:0 usec > max. jitter:29 usec >=20 > chrt -o 0 ./a.out=20 > average:153 usec > min. jitter:0 usec > max. jitter:37035 usec >=20 > So the problem is located first in the new sched_rt_runtime_us default > value and second in the "Group CPU scheduler". Well, if you have group scheduling configured I think you should do both # echo -1 > /proc/sys/kernel/sched_rt_runtime_us # echo -1 > /dev/cgroup/cpu.rt_runtime_us if /dev/cgroup is the mount point of the cgroup file system. In situations like the one you are describing, this worked for me... Hope that it also helps you! :-) Regards, Dario --=20 <> (Raistlin Majere, DragonLance Chronicles -Dragons of Spring Drawning-) ---------------------------------------------------------------------- Dario Faggioli GNU/Linux Registered User: #340657 Web: http://www.linux.it/~raistlin Blog: http://blog.linux.it/raistlin SIP Account: dario.faggioli@sipproxy.wengo.fr or raistlin@ekiga.net Jabber Account: dario.faggioli@jabber.org/WengoPhone GnuPG Key ID: 4DC83AC4 GnuPG Key Fingerprint: 2A78 AD5D B9CF A082 0836 08AD 9385 DA04 4DC8 3AC4 --=-7JOx75FXGPoxnNgO/obs Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQBIqKL+k4XaBE3IOsQRAkj8AKCVioKlm8iWuoZOxSRe3toJS2tdjgCePHAG +R0rI7q84cV6pPpN5TyVnCE= =Cndj -----END PGP SIGNATURE----- --=-7JOx75FXGPoxnNgO/obs--