Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264836AbVBDWXj (ORCPT ); Fri, 4 Feb 2005 17:23:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266756AbVBDWTM (ORCPT ); Fri, 4 Feb 2005 17:19:12 -0500 Received: from gizmo05ps.bigpond.com ([144.140.71.40]:27522 "HELO gizmo05ps.bigpond.com") by vger.kernel.org with SMTP id S266645AbVBDViu (ORCPT ); Fri, 4 Feb 2005 16:38:50 -0500 Message-ID: <4203EB61.3010603@bigpond.net.au> Date: Sat, 05 Feb 2005 08:38:41 +1100 From: Peter Williams User-Agent: Mozilla Thunderbird 0.9 (X11/20041127) X-Accept-Language: en-us, en MIME-Version: 1.0 To: "Jack O'Quin" CC: Paul Davis , "Bill Huey (hui)" , Ingo Molnar , Nick Piggin , Con Kolivas , linux , rlrevell@joe-job.com, CK Kernel , utz , Andrew Morton , alexn@dsv.su.se, Rui Nuno Capela , Chris Wright , Arjan van de Ven Subject: Re: [patch, 2.6.11-rc2] sched: RLIMIT_RT_CPU_RATIO feature References: <200502031420.j13EKwFx005545@localhost.localdomain> <42029C23.1000300@bigpond.net.au> <87u0oscm6s.fsf@sulphur.joq.us> In-Reply-To: <87u0oscm6s.fsf@sulphur.joq.us> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1947 Lines: 50 Jack O'Quin wrote: > Peter Williams writes: > > >>Paul Davis wrote: >> >>>There are several kernel-side attributes that would make JACK better >>>from my perspective: >>> * better ways to acquire and release RT scheduling >> >>I'm no expert on the topic but it would seem to me that the mechanisms >>associated with the capable() function are intended to provide a >>consistent and extensible interface to the control of privileged >>operations with possible finer grained control than "root 'yes' and >>everybody else 'no'". Maybe the way to solve this problem is to >>modify the interpretation of capable(CAP_SYS_NICE) so that it returns >>true when invoked by a task setuid to a nominated uid in addition to >>zero? > > > That is essentially what the RT-LSM does. At exec() time RT-LSM turns > on CAP_SYS_NICE for appropriate process images. > > In the current implementation this is only done per-group not > per-user. Adding UID as well as GID granularity should be easy. We > didn't do it because we didn't really need it. If there's a use for > it, I have no objection to adding it. It could even compatibly be > added later. If what you have is adequate I wouldn't suggest changing it. My use of uid in my rant was just to illustrate a general idea. > > Many distributions require users to join group `audio' anyway to gain > access to the sound card. We found it convenient to piggy-back on > that mechanism. > > I believe Paul considers this adequate for his requirements. :-) Peter -- Peter Williams pwil3058@bigpond.net.au "Learning, n. The kind of ignorance distinguishing the studious." -- Ambrose Bierce - 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/