Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262184AbVAYWFy (ORCPT ); Tue, 25 Jan 2005 17:05:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262166AbVAYWFj (ORCPT ); Tue, 25 Jan 2005 17:05:39 -0500 Received: from fw.osdl.org ([65.172.181.6]:28830 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S262184AbVAYWDr (ORCPT ); Tue, 25 Jan 2005 17:03:47 -0500 Date: Tue, 25 Jan 2005 14:03:02 -0800 From: Chris Wright To: Ingo Molnar Cc: Chris Wright , "Jack O'Quin" , Paul Davis , Con Kolivas , linux , rlrevell@joe-job.com, CK Kernel , utz , Andrew Morton , alexn@dsv.su.se, Rui Nuno Capela , Arjan van de Ven , Nick Piggin Subject: Re: [patch, 2.6.11-rc2] sched: /proc/sys/kernel/rt_cpu_limit tunable Message-ID: <20050125140302.C24171@build.pdx.osdl.net> References: <20050122165458.GA14426@elte.hu> <87hdl940ph.fsf@sulphur.joq.us> <20050124085902.GA8059@elte.hu> <20050124125814.GA31471@elte.hu> <87k6q2umla.fsf@sulphur.joq.us> <20050125083724.GA4812@elte.hu> <87oefdfaxp.fsf@sulphur.joq.us> <20050125214900.GA9421@elte.hu> <20050125135508.A24171@build.pdx.osdl.net> <20050125215758.GA10811@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20050125215758.GA10811@elte.hu>; from mingo@elte.hu on Tue, Jan 25, 2005 at 10:57:58PM +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1475 Lines: 31 * Ingo Molnar (mingo@elte.hu) wrote: > * Chris Wright wrote: > > * Ingo Molnar (mingo@elte.hu) wrote: > > > well, there's setrlimit, so you could add a jackd client callback that > > > instructs all clients to change their RT_CPU_RATIO rlimit. In theory we > > > could try to add a new rlimit syscall that changes another task's rlimit > > > (right now the syscalls only allow the changing of the rlimit of the > > > current task) - that would enable utilities to change the rlimit of all > > > tasks in the system, achieving the equivalent of a global sysctl. > > > > We've talked about smth. similar in another thread. I'm not opposed > > to the idea. > > did that thread go into technical details? There are some rlimit users > that might not be prepared to see the rlimit change under them. The > RT_CPU_RATIO one ought to be safe, but generally i'm not so sure. Not really. I mentioned the above, as well as the security concern. Right now, at least the task_setrlimit hook would have to change to take into account the task. And I never convinced myself that async changes would be safe for each rlimit. thanks, -chris -- Linux Security Modules http://lsm.immunix.org http://lsm.bkbits.net - 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/