Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265399AbTFSEVj (ORCPT ); Thu, 19 Jun 2003 00:21:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265420AbTFSEVb (ORCPT ); Thu, 19 Jun 2003 00:21:31 -0400 Received: from users.ccur.com ([208.248.32.211]:37706 "HELO rudolph.ccur.com") by vger.kernel.org with SMTP id S265399AbTFSEV3 (ORCPT ); Thu, 19 Jun 2003 00:21:29 -0400 Date: Thu, 19 Jun 2003 00:34:41 -0400 From: "'joe.korty@ccur.com'" To: "Perez-Gonzalez, Inaky" Cc: "'Andrew Morton'" , "'george anzinger'" , "'linux-kernel@vger.kernel.org'" , "'mingo@elte.hu'" Subject: Re: O(1) scheduler seems to lock up on sched_FIFO and sched_RR ta sks Message-ID: <20030619043441.GA1304@rudolph.ccur.com> Reply-To: Joe Korty References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1230 Lines: 25 On Wed, Jun 18, 2003 at 06:44:42PM -0700, Perez-Gonzalez, Inaky wrote: > > Now that we are at that, it might be wise to add a higher-than-anything > priority that the kernel code can use (what would be 100 for user space, > but off-limits), so even FIFO 99 code in user space cannot block out > the migration thread, keventd and friends. I would prefer users have the ability to put one or two truly critical RT tasks above keventd & family. Such tasks would have to follow certain rules .. run & sleep quick .. limited or no device IO .. most communication to other tasks through shared memory .. possibly others. There are those willing to follow whatever rules necessary & split up their application into tasks any which way in order to get high responsiveness to a critical but small part of their application. If you follow the rules, you should be allowed to put a carefully crafted task above the system daemons (with the possible exception of the migration daemon). Joe - 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/