From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266585AbTGFBOw (ORCPT ); Sat, 5 Jul 2003 21:14:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266586AbTGFBOw (ORCPT ); Sat, 5 Jul 2003 21:14:52 -0400 Received: from mail.jlokier.co.uk ([81.29.64.88]:37515 "EHLO mail.jlokier.co.uk") by vger.kernel.org with ESMTP id S266585AbTGFBOv (ORCPT ); Sat, 5 Jul 2003 21:14:51 -0400 Date: Sun, 6 Jul 2003 02:28:57 +0100 From: Jamie Lokier To: Daniel Phillips Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: 2.5.74-mm1 Message-ID: <20030706012857.GA29544@mail.jlokier.co.uk> References: <20030703023714.55d13934.akpm@osdl.org> <200307052309.12680.phillips@arcor.de> <20030705214413.GA28824@mail.jlokier.co.uk> <200307060010.26002.phillips@arcor.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200307060010.26002.phillips@arcor.de> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Daniel Phillips wrote: > What are you going to do if you have one > application you want to take priority, re-nice the other 50? Is that effective? It might be just the trick. > > Something I've often thought would fix this is to allow normal users > > to set negative priority which is limited to using X% of the CPU - > > i.e. those tasks would have their priority raised if they spent more > > than a small proportion of their time using the CPU. > > That's essentially SCHED_RR. As I mentioned above, it's not clear > to me why SCHED_RR requires superuser privilege, since the amount of > CPU you can burn that way is bounded. Well, the total of all > SCHED_RR processes would need to be bounded as well, which is > straightforward. Your last point is most important. At the moment, a SCHED_RR process with a bug will basically lock up the machine, which is totally inappropriate for a user app. -- Jamie