From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030234AbWGMQnv (ORCPT ); Thu, 13 Jul 2006 12:43:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030236AbWGMQnv (ORCPT ); Thu, 13 Jul 2006 12:43:51 -0400 Received: from mustang.oldcity.dca.net ([216.158.38.3]:6036 "HELO mustang.oldcity.dca.net") by vger.kernel.org with SMTP id S1030234AbWGMQnu (ORCPT ); Thu, 13 Jul 2006 12:43:50 -0400 Subject: Re: Where is RLIMIT_RT_CPU? From: Lee Revell To: Jean-Marc Valin Cc: linux-kernel@vger.kernel.org, Ingo Molnar In-Reply-To: <1152663825.27958.5.camel@localhost> References: <1152663825.27958.5.camel@localhost> Content-Type: text/plain Date: Thu, 13 Jul 2006 12:43:59 -0400 Message-Id: <1152809039.8237.48.camel@mindpipe> Mime-Version: 1.0 X-Mailer: Evolution 2.6.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2006-07-12 at 10:23 +1000, Jean-Marc Valin wrote: > Hi, > > I saw many references to RLIMIT_RT_CPU (e.g. in > http://lwn.net/Articles/120797/ ) as a way of limiting the amount of CPU > an unprivileged task can use at real-time priority. My understand was > that the feature had been merged into 2.6.12 as part of Ingo's rt-limit > patches. Unfortunately, I can't find any reference to that on my system > (latest Ubuntu), so I'm wondering where it's gone. Has it been removed, > renamed, ...? Considering that Ubuntu Dapper currently allows any user > to make unlimited use of realtime scheduling, this feature would be > really useful to prevent user apps from accidently crashing the system. It was not merged. This problem should be addressed by a userspace RT watchdog. Ubuntu should not have shipped their system with unlimited non-root realtime enabled and no watchdog. Lee