Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261711AbUKIWYC (ORCPT ); Tue, 9 Nov 2004 17:24:02 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261721AbUKIWYC (ORCPT ); Tue, 9 Nov 2004 17:24:02 -0500 Received: from mx1.elte.hu ([157.181.1.137]:236 "EHLO mx1.elte.hu") by vger.kernel.org with ESMTP id S261711AbUKIWXx (ORCPT ); Tue, 9 Nov 2004 17:23:53 -0500 Date: Wed, 10 Nov 2004 00:26:00 +0100 From: Ingo Molnar To: Mark_H_Johnson@raytheon.com Cc: Amit Shah , Karsten Wiese , Bill Huey , Adam Heath , emann@mrv.com, Gunther Persoons , "K.R. Foley" , linux-kernel@vger.kernel.org, Florian Schmidt , Fernando Pablo Lopez-Lezcano , Lee Revell , Rui Nuno Capela , Shane Shrybman , Thomas Gleixner , Michal Schmidt Subject: Re: [patch] Real-Time Preemption, -RT-2.6.10-rc1-mm3-V0.7.23 Message-ID: <20041109232600.GB14503@elte.hu> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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=-2.201, required 5.9, BAYES_00 -4.90, SORTED_RECIPS 2.70 X-ELTE-SpamLevel: X-ELTE-SpamScore: -2 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1768 Lines: 43 * Mark_H_Johnson@raytheon.com wrote: > >i have released the -V0.7.23 Real-Time Preemption patch, which can be > >downloaded from the usual place: > > > > http://redhat.com/~mingo/realtime-preempt/ > > A few notes on results from running with this patch (well, actually > -EA that Ingo provided separately). > > [1] Build problems, separately reported to Ingo with CONFIG_PREEMPT_RT > enabled on x86 and you have modules using kunmap_atomic. Fix by adding > kunmap_virt and kmap_to_page to the list of exports. these should be fixed in -V0.7.24 which i uploaded shortly after -V0.7.23, based on your reports. In any case, the export problems trigger with CONFIG_HIGHMEM and the affected subsystems compiled as modules. > [2] The live lock that I was having seems to have been killed based on > an hour of testing (I could usually cause it in 5 minutes or less). great! > [4] Application level latencies are OK but not great. > X test - only 90% of CPU loops are within 100 usec of nominal value. > In previous RT kernels I got > 99% with 100 usec. this might be a side-effect of the chrt-ing of events/[0|1] and/or ksoftirqd (which we did to debug the 'freeze' problems) - are those still chrt-ed? Please review and double-check all SCHED_FIFO tasks in the system and keep only those that are absolutely necessary for latencytest's operation [i.e. the soundcard IRQ and latencytest itself] - everything else should be SCHED_OTHER. Do latencies get any better if you do this? 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/