Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262275AbUKDQ4Q (ORCPT ); Thu, 4 Nov 2004 11:56:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262293AbUKDQ4Q (ORCPT ); Thu, 4 Nov 2004 11:56:16 -0500 Received: from bos-gate1.raytheon.com ([199.46.198.230]:52526 "EHLO bos-gate1.raytheon.com") by vger.kernel.org with ESMTP id S262275AbUKDQ4N (ORCPT ); Thu, 4 Nov 2004 11:56:13 -0500 Subject: Re: [patch] Real-Time Preemption, -RT-2.6.10-rc1-mm2-V0.7.1 To: Ingo Molnar Cc: Karsten Wiese , Bill Huey , Adam Heath , "K.R. Foley" , linux-kernel@vger.kernel.org, Florian Schmidt , Fernando Pablo Lopez-Lezcano , Lee Revell , Rui Nuno Capela , Thomas Gleixner , Michal Schmidt X-Mailer: Lotus Notes Release 5.0.8 June 18, 2001 Message-ID: From: Mark_H_Johnson@raytheon.com Date: Thu, 4 Nov 2004 10:53:58 -0600 X-MIMETrack: Serialize by Router on RTSHOU-DS01/RTS/Raytheon/US(Release 6.5.2|June 01, 2004) at 11/04/2004 10:54:09 AM MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII X-SPAM: 0.00 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1447 Lines: 30 >> I can set those as well but then I'd probably have to follow with >> the X server and everything else in the chain. The starvation problem >> ripples across the system. > >X should be scheduled on the other CPU just fine. Only per-CPU kernel >threads (which are affine to their particular CPU) are affected by this >problem - ordinary tasks not. I.e. the system threads that have /0 and >/1 in their name. In theory you should not even need to chrt the hardirq >threads, those should schedule fine too. Perhaps "should be fine" but the test I just ran indicates otherwise. The kernel is -V0.7.7 plus the patch you just sent me. All IRQ and /# tasks were set to RT priority 99. Started the X test and the display locked up almost immediately while ping responses continued to flow on a regular basis. After several seconds I could see the display update / move the mouse & then the display locked up again. It went back and forth a couple cycles and did not get unstuck until the RT audio application quit (over 250000 samples). I will let it run to see if I can reproduce the deadlock or if the symptoms change with one of the other tests. --Mark H Johnson - 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/