Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265420AbTFSEYR (ORCPT ); Thu, 19 Jun 2003 00:24:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265421AbTFSEYR (ORCPT ); Thu, 19 Jun 2003 00:24:17 -0400 Received: from fmr01.intel.com ([192.55.52.18]:14070 "EHLO hermes.fm.intel.com") by vger.kernel.org with ESMTP id S265420AbTFSEYQ convert rfc822-to-8bit (ORCPT ); Thu, 19 Jun 2003 00:24:16 -0400 Message-ID: From: "Perez-Gonzalez, Inaky" To: "'Joe Korty'" Cc: "'linux-kernel@vger.kernel.org'" Subject: RE: O(1) scheduler seems to lock up on sched_FIFO and sched_RR ta sks Date: Wed, 18 Jun 2003 21:38:12 -0700 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2653.19) Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1339 Lines: 28 > From: 'joe.korty@ccur.com' [mailto:joe.korty@ccur.com] > > 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. Agreed - see my answers to George Anzinger and Robert Love; I wasn't precise enough on meaning "yeah, you should be able to reprioritize it at will". My point is that user programs have a limit that they cannot use, while kernel threads can use the user's priority space and their highest priority space. I?aky P?rez-Gonz?lez -- Not speaking for Intel -- all opinions are my own (and my fault) - 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/