Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261239AbUKWNpm (ORCPT ); Tue, 23 Nov 2004 08:45:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261238AbUKWNo2 (ORCPT ); Tue, 23 Nov 2004 08:44:28 -0500 Received: from mx2.elte.hu ([157.181.151.9]:50617 "EHLO mx2.elte.hu") by vger.kernel.org with ESMTP id S261239AbUKWNnz (ORCPT ); Tue, 23 Nov 2004 08:43:55 -0500 Date: Tue, 23 Nov 2004 15:46:22 +0100 From: Ingo Molnar To: Rui Nuno Capela Cc: Florian Schmidt , linux-kernel@vger.kernel.org, Lee Revell , mark_h_johnson@raytheon.com, "K.R. Foley" , Bill Huey , Adam Heath , Thomas Gleixner , Michal Schmidt , Fernando Pablo Lopez-Lezcano , Karsten Wiese , Gunther Persoons , emann@mrv.com, Shane Shrybman , Amit Shah , Esben Nielsen Subject: Re: [patch] Real-Time Preemption, -RT-2.6.10-rc2-mm2-V0.7.30-2 Message-ID: <20041123144622.GA20085@elte.hu> References: <20041118164612.GA17040@elte.hu> <20041122005411.GA19363@elte.hu> <20041122020741.5d69f8bf@mango.fruits.de> <20041122094602.GA6817@elte.hu> <56781.195.245.190.93.1101119801.squirrel@195.245.190.93> <20041122132459.GB19577@elte.hu> <20041122142744.0a29aceb@mango.fruits.de> <65529.195.245.190.94.1101133129.squirrel@195.245.190.94> <20041122154516.GC2036@elte.hu> <9182.195.245.190.93.1101142412.squirrel@195.245.190.93> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9182.195.245.190.93.1101142412.squirrel@195.245.190.93> 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: 1600 Lines: 48 * Rui Nuno Capela wrote: > OK. I tried 14 instances of jack_test. I even modded Florian's > original source code, to let each client instance have 4 ins and 4 > outs, and to make things a litle bit heavier, all 4 inputs are mixed > into each of the 4 outputs. i tried your new test-client, and i've got a generic question: should a jack client be able to generate an xrun via, other than via overloading jackd? E.g. i'm wondering about the following behavior: if start up jackd in the usual way: jackd -R -P20 -dalsa -dhw:0 -r44100 -p64 -n2 -S -P and then i start a single test-client (jack_test.cpp): # ./jack_test seconds to run: 60 client_new: jack_test-4215 port_register set_process_callback activate running and then if i now Ctrl-Z the Jack client, i get an immediate xrun message from jackd: **** alsa_pcm: xrun of at least 2.119 msecs and when i 'fg' the client again then jackd sees a big delay: **** alsa_pcm: xrun of at least 742.064 msecs corresponding the amount of time i waited between the Ctrl-Z and the 'fg'. since the client runs as SCHED_OTHER, doesnt this mean that simple delays between SCHED_OTHER tasks could cause xruns in jackd too? A SCHED_OTHER task can be delayed indefinitely at any stage. So shouldnt the test-clients have RT priority as well, to guarantee xrun-less jackd? 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/