From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750780AbWGQN7v (ORCPT ); Mon, 17 Jul 2006 09:59:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750781AbWGQN7v (ORCPT ); Mon, 17 Jul 2006 09:59:51 -0400 Received: from ms-smtp-02.nyroc.rr.com ([24.24.2.56]:31187 "EHLO ms-smtp-02.nyroc.rr.com") by vger.kernel.org with ESMTP id S1750780AbWGQN7u (ORCPT ); Mon, 17 Jul 2006 09:59:50 -0400 Subject: Re: Where is RLIMIT_RT_CPU? From: Steven Rostedt To: Jean-Marc Valin Cc: Esben Nielsen , Lee Revell , Arjan van de Ven , linux-kernel@vger.kernel.org, Ingo Molnar In-Reply-To: <1153137181.24228.16.camel@idefix.homelinux.org> References: <1152663825.27958.5.camel@localhost> <1152809039.8237.48.camel@mindpipe> <1152869952.6374.8.camel@idefix.homelinux.org> <1152919240.6374.38.camel@idefix.homelinux.org> <1152971896.16617.4.camel@mindpipe> <1152973159.6374.59.camel@idefix.homelinux.org> <1152974578.3114.24.camel@laptopd505.fenrus.org> <1152975857.6374.65.camel@idefix.homelinux.org> <1152978284.16617.7.camel@mindpipe> <1153009392.6374.77.camel@idefix.homelinux.org> <1153044864.6374.135.camel@idefix.homelinux.org> <1153137181.24228.16.camel@idefix.homelinux.org> Content-Type: text/plain Date: Mon, 17 Jul 2006 09:59:13 -0400 Message-Id: <1153144753.652.12.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.6.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2006-07-17 at 21:53 +1000, Jean-Marc Valin wrote: > > Why not? It could be nice as well if someone wants to implement that. > I'd already be quite happy to just have basic control on the CPU time. > Have you thought about using something like Xen? Have a virtual machine that you can even give root access to users, and still have control of the actual physical machine. > As I mentioned earlier, it's not about total lock-up, but having things > run relatively smoothly and (if possible?) even fairly. One issue I think you might have is what exactly is a CPU limit? If the system is idle, and you have an app that goes into a busy loop, do you kill it after it hits the limit, even if it isn't RT? Or do you just force it to schedule? Or do you consider idle a special case? Do you want just the apps to be limited, or all the apps that belong to a specific user. >>From this thread, it seems your goal is to have a single console that users can log into and run a RT thread for audio but still not be able to lock up the entire system. Right? So having an RT limit for this use might actually be beneficial. But this is a very rare case, and if you are the only one needing this type of feature, then it will likely not make it into the kernel. But it if turns out that lots of people like this feature, and want it, then it might have a chance, if there is no other way to accomplish it. Currently, it looks like you can use either Xen or just stick to one of the patches you mentioned earlier. -- Steve