From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261885AbVANEEn (ORCPT ); Thu, 13 Jan 2005 23:04:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261873AbVANEEn (ORCPT ); Thu, 13 Jan 2005 23:04:43 -0500 Received: from smtp105.mail.sc5.yahoo.com ([66.163.169.225]:46224 "HELO smtp105.mail.sc5.yahoo.com") by vger.kernel.org with SMTP id S261885AbVANEEi (ORCPT ); Thu, 13 Jan 2005 23:04:38 -0500 Subject: Re: [PATCH] [request for inclusion] Realtime LSM From: Nick Piggin To: Con Kolivas Cc: Paul Davis , Andrew Morton , lkml@s2y4n2c.de, rlrevell@joe-job.com, arjanv@redhat.com, joq@io.com, chrisw@osdl.org, mpm@selenic.com, hch@infradead.org, mingo@elte.hu, alan@lxorguk.ukuu.org.uk, linux-kernel@vger.kernel.org In-Reply-To: <41E73E98.8070603@kolivas.org> References: <200501140330.j0E3UCiG027037@localhost.localdomain> <41E73E98.8070603@kolivas.org> Content-Type: text/plain Date: Fri, 14 Jan 2005 15:04:11 +1100 Message-Id: <1105675451.5402.73.camel@npiggin-nld.site> Mime-Version: 1.0 X-Mailer: Evolution 2.0.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2005-01-14 at 14:38 +1100, Con Kolivas wrote: > Paul Davis wrote: > > its a fine answer, but its the answer to a slightly different > > question. if anyone (maybe us audio freaks, maybe someone else) comes > > up with a reason to want "The Real SCHED_FIFO", the original question > > will have gone unanswered. > > Ah then you missed something. You can set the max cpu of SCHED_ISO to > 100% and then you have it. > Is that a good solution? I'm not sure if it is wise to try to masquerade SCHED_ISO as an unprivileged RT class. I mean what happens if two users are trying to run independent SCHED_ISO systems? Both will probably break, right? And how can you provide _any_ guarantees in an arbitrary environment without this becoming a privileged operation? I can't quite get my head around that at the moment... I guess if you have SCHED_ISO start out with 0 guarantees, and have root dole some out, then it may be workable. But then that is just another specialised ad hoc sort of hack wouldn't it? (not talking about SCHED_ISO itself, but the granting of the privilege to use it).