Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S270006AbUJNJSj (ORCPT ); Thu, 14 Oct 2004 05:18:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S270009AbUJNJSj (ORCPT ); Thu, 14 Oct 2004 05:18:39 -0400 Received: from mx2.elte.hu ([157.181.151.9]:41445 "EHLO mx2.elte.hu") by vger.kernel.org with ESMTP id S270006AbUJNJSa (ORCPT ); Thu, 14 Oct 2004 05:18:30 -0400 Date: Thu, 14 Oct 2004 11:19:53 +0200 From: Ingo Molnar To: Florian Schmidt Cc: linux-kernel@vger.kernel.org, Lee Revell , Rui Nuno Capela , Mark_H_Johnson@Raytheon.com, "K.R. Foley" , Daniel Walker , Bill Huey , Andrew Morton Subject: Re: [patch] Real-Time Preemption, -VP-2.6.9-rc4-mm1-U0 Message-ID: <20041014091953.GA21635@elte.hu> References: <20041011215909.GA20686@elte.hu> <20041012091501.GA18562@elte.hu> <20041012123318.GA2102@elte.hu> <20041012195424.GA3961@elte.hu> <20041013061518.GA1083@elte.hu> <20041014002433.GA19399@elte.hu> <20041014105711.654efc56@mango.fruits.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20041014105711.654efc56@mango.fruits.de> User-Agent: Mutt/1.4.1i X-ELTE-SpamVersion: MailScanner 4.31.6-itk1 (ELTE 1.2) SpamAssassin 2.63 ClamAV 0.73 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1392 Lines: 39 * Florian Schmidt wrote: > Cool :) > > Say, does it still apply that one should not use unthreaded IRQ > handlers for all IRQ's when using PREEMPT_REALTIME (Except maybe for > the keyboard)? yes - and this kernel simply does not allow the un-threading of interrupt handlers anymore, so you cannot accidentally misconfigure it. (Not even the keyboard interrupt is an exception, it would have lock-ripple-effects elsewhere.) so the preferred (and only) interface to mark interrupts 'high prio' is via process priorities. Starting from the -U1 kernel it will be possible to do this: chrt -f 60 -p `ps -C 'IRQ:1' -o pid=` chrt -f 60 -p `ps -C 'IRQ:8' -o pid=` this sets the keyboard and the RT-timer interrupt to FIFO:60. In -U0 this is not possible because 'ps -C' does not handle kernel threads with a space in their name. So there you'd need some wacky thing like: chrt -f 60 -p `ps ax -o pid= -o comm= | grep "IRQ 1$" | cut -dI -f1` chrt -f 60 -p `ps ax -o pid= -o comm= | grep "IRQ 8$" | cut -dI -f1` (someone should fix procps - or does it intentionally break with whitespace command-strings?) Ingo - 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/