Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S272587AbTHEJEw (ORCPT ); Tue, 5 Aug 2003 05:04:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S272588AbTHEJEw (ORCPT ); Tue, 5 Aug 2003 05:04:52 -0400 Received: from pop.gmx.net ([213.165.64.20]:748 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S272587AbTHEJEv (ORCPT ); Tue, 5 Aug 2003 05:04:51 -0400 Message-Id: <5.2.1.1.2.20030805104620.01974e28@pop.gmx.net> X-Mailer: QUALCOMM Windows Eudora Version 5.2.1 Date: Tue, 05 Aug 2003 11:09:02 +0200 To: Con Kolivas From: Mike Galbraith Subject: Re: [PATCH] O13int for interactivity Cc: Oliver Neukum , Andrew Morton , piggin@cyberone.com.au, linux-kernel@vger.kernel.org, mingo@elte.hu, felipe_alfaro@linuxmail.org In-Reply-To: <200308051843.54357.kernel@kolivas.org> References: <5.2.1.1.2.20030805102719.01a06d48@pop.gmx.net> <200308051012.12951.oliver@neukum.org> <5.2.1.1.2.20030805102719.01a06d48@pop.gmx.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1410 Lines: 32 At 06:43 PM 8/5/2003 +1000, Con Kolivas wrote: >On Tue, 5 Aug 2003 18:27, Mike Galbraith wrote: > > At 06:20 PM 8/5/2003 +1000, Con Kolivas wrote: > > >Every experiment I've tried at putting tasks at the start of the queue > > >instead > > >of the end has resulted in some form of starvation so should not be > > > possible for any user task and I've abandoned it. > > > > (ditto:) > >Superuser access real time tasks may be worth reconsidering though... If they were guaranteed ultra-light, maybe, but userland is just not trustworthy. Better imho would be something like Davide's SOFT_RR with an additional automatic priority adjust per cpu usage or something (cpu usage being a [very] little bit of a latency hint, and a great 'hurt me' hint). Best would be an API that allowed userland applications to describe their latency requirements explicitly, with the scheduler watching users of this API like a hawk, ever ready to sanction abusers. Anything I think about in this area gets uncomfortably close to hard rt though, and all of the wisdom I've heard on LKLM over the years wrt separation of problem spaces comes flooding back. -Mike - 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/