From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261240AbULAN1r (ORCPT ); Wed, 1 Dec 2004 08:27:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261242AbULAN1r (ORCPT ); Wed, 1 Dec 2004 08:27:47 -0500 Received: from mx1.elte.hu ([157.181.1.137]:62861 "EHLO mx1.elte.hu") by vger.kernel.org with ESMTP id S261240AbULAN1p (ORCPT ); Wed, 1 Dec 2004 08:27:45 -0500 Date: Wed, 1 Dec 2004 14:27:10 +0100 From: Ingo Molnar To: Wen-chien Jesse Sung Cc: linux-kernel@vger.kernel.org Subject: [patch] Real-Time Preemption, -RT-2.6.10-rc2-mm3-V0.7.31-17 Message-ID: <20041201132710.GA8328@elte.hu> References: <41AD9A33.3070205@cola.voip.idv.tw> <20041201113746.GA21640@elte.hu> <20041201115221.GA22697@elte.hu> <41ADBE1C.9010807@cola.voip.idv.tw> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <41ADBE1C.9010807@cola.voip.idv.tw> 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 * Wen-chien Jesse Sung wrote: > I redo the test with a vanilla 2.6.10-rc2-mm3-V0.7.31-16 again, and it > still hangs at hwclock. Here's the complete config file. ok, could you try the -17 kernel i've just uploaded to the usual place: http://redhat.com/~mingo/realtime-preempt/ does this fix the lockup? i believe the lockup is an interesting side-effect of threading IRQ#0: any code within the kernel that loops on jiffies will produce a lockup, because it starves the timer IRQ thread. The RTC driver had two such places, but i also found one in the IRQ-autodetect code. We want to eliminate such code anyway, and a lockup is certainly an effective way to detect it ;) to debug such lockups in the future you can do: echo 1 > /proc/sys/kernel/debug_direct_keyboard /sbin/hwclock ... and use the sysrq keys to get a stack dump of the lockup. NOTE: dont use the keyboard in this mode for too long, it can lock up. Ingo