From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 26 Apr 2002 08:59:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 26 Apr 2002 08:58:58 -0400 Received: from gwsmtp.thomson-csf.com ([195.101.39.226]:3335 "EHLO gwsmtp.thomson-csf.com") by vger.kernel.org with ESMTP id convert rfc822-to-8bit; Fri, 26 Apr 2002 08:58:31 -0400 Message-ID: <3CC58155000078A8@bgxplex3.bgx.airsys.thomson-csf.com> (added by postmaster@bgxplex3.bgx.airsys.thomson-csf.com) Content-Type: text/plain; charset=US-ASCII From: Nicolas Bonnefon Organization: Thales Air Defence To: Eldor =?iso-8859-1?q?R=F8dseth?= (ETO) , "'linux-kernel@vger.kernel.org'" Subject: Re: SCHED_FIFO and SCHED_RR in 2.4.7-10custom kernel Date: Fri, 26 Apr 2002 14:52:24 +0200 X-Mailer: KMail [version 1.3.1] In-Reply-To: MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > My application uses the possibility to change scheduling mechanism. When > changing from SCHED_OTHER to SCHED_FIFO or SCHED_RR, my application causes > the whole Linux PC to "hang". Prior to launching my own application, I > launch a "superbash" application with higher priority than my own > application. But I am not able to switch to the window where this > "superbash" application is running to kill my own application. The PC > simply does not respond to any input from the keyboard. Have you tried without running X ? A SCHED_FIFO or SCHED_RR task has ALWAYS priority over any SCHED_OTHER task, so if your application sits in an infinite loop without blocking, the window manager cannot preempt it and you simply cannot switch x-term. I think you should carefully debug your app in SCHED_OTHER mode first, and then switch to some real-time policy. > > I have used this mechanism before, and I am quite confident that this > worked under kernel 2.4.2. Are you aware of anything that could explain > this behaviour? It would be surprising, but if you were sure of that, it would deserve some deeper investigations ! Regards -- Nicolas Bonnefon Radar Development/Digital Processing Engineer Thales Air Defence - 7-9 rue des Mathurins 92223 Bagneux - France