From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263234AbUKBNDK (ORCPT ); Tue, 2 Nov 2004 08:03:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261861AbUKBNDJ (ORCPT ); Tue, 2 Nov 2004 08:03:09 -0500 Received: from mail17.syd.optusnet.com.au ([211.29.132.198]:2969 "EHLO mail17.syd.optusnet.com.au") by vger.kernel.org with ESMTP id S263618AbUKBNCa (ORCPT ); Tue, 2 Nov 2004 08:02:30 -0500 Message-ID: <4187854C.6000803@kolivas.org> Date: Wed, 03 Nov 2004 00:02:04 +1100 From: Con Kolivas User-Agent: Mozilla Thunderbird 0.8 (X11/20040913) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Ingo Molnar Cc: linux kernel mailing list , Andrew Morton Subject: Re: [PATCH] optional non-interactive mode for cpu scheduler References: <41871BA7.6070300@kolivas.org> <20041102125218.GH15290@elte.hu> In-Reply-To: <20041102125218.GH15290@elte.hu> X-Enigmail-Version: 0.86.1.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig938555BCFD0B673CC092E197" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig938555BCFD0B673CC092E197 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Ingo Molnar wrote: > * Con Kolivas wrote: > > >>optional non-interactive mode for cpu scheduler > > > i think the following scheme would work better: > > - introduce a new SCHED_CPUBOUND policy > - return ->static_prio + 5 for such tasks > - keep their timeslice based off ->static_prio > > the point is this: such tasks would thus be automatically and > perpetually considered 'CPU hogs'. Applications cannot abuse this > mechanism because they get the maximum 'penalty'. > > and as a bonus, no magic sysctl and inherently more flexibility. > > (note that this scheme has advantages above nice +5 because nice +5 > still has the interactivity stuff on which can create priority > fluctuations and may thus affect workloads.) > > if you agree with this scheme, would you be interested in implementing > this? The better cpu proportion guarantee without low latency of such a policy would be desirable to video encoding in the background while capturing in the foreground as one immediately recognisable purpose, and there are likely numerous others, so I agree it's a good idea. However the non-interactive mode addresses a number of different needs that seem to have come up. Specifically: I have had users report great success with such a mode on my own scheduler in multiple X session setups where very choppy behaviour occurs in mainline. Many high performance computing people do not wish interactivity code modifying their choice of latency/distribution - admittedly this is a soft one. What are your thoughts on this? Con --------------enig938555BCFD0B673CC092E197 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.6 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFBh4VMZUg7+tp6mRURAsw9AKCPj1uJs2swoHO/8e264ZqOMEjLuwCcCzok Wmy51ANe2qGFNbQPZofimww= =x4a8 -----END PGP SIGNATURE----- --------------enig938555BCFD0B673CC092E197--