Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262354AbVAOXCY (ORCPT ); Sat, 15 Jan 2005 18:02:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262355AbVAOXCY (ORCPT ); Sat, 15 Jan 2005 18:02:24 -0500 Received: from mail.joq.us ([67.65.12.105]:43906 "EHLO sulphur.joq.us") by vger.kernel.org with ESMTP id S262354AbVAOXCU (ORCPT ); Sat, 15 Jan 2005 18:02:20 -0500 To: Ingo Molnar Cc: Chris Wright , Matt Mackall , Paul Davis , Christoph Hellwig , Andrew Morton , Lee Revell , arjanv@redhat.com, alan@lxorguk.ukuu.org.uk, linux-kernel@vger.kernel.org Subject: Re: [PATCH] [request for inclusion] Realtime LSM References: <20050110212019.GG2995@waste.org> <200501111305.j0BD58U2000483@localhost.localdomain> <20050111191701.GT2940@waste.org> <20050111125008.K10567@build.pdx.osdl.net> <20050111205809.GB21308@elte.hu> <20050111131400.L10567@build.pdx.osdl.net> <20050111212719.GA23477@elte.hu> <87fz15j325.fsf@sulphur.joq.us> <20050115134922.GA10114@elte.hu> From: "Jack O'Quin" Date: Sat, 15 Jan 2005 17:02:41 -0600 In-Reply-To: <20050115134922.GA10114@elte.hu> (Ingo Molnar's message of "Sat, 15 Jan 2005 14:49:22 +0100") Message-ID: <874qhiwb1q.fsf@sulphur.joq.us> User-Agent: Gnus/5.1006 (Gnus v5.10.6) XEmacs/21.4 (Corporate Culture, linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1447 Lines: 35 Ingo Molnar writes: > * Jack O'Quin wrote: > >> OK, I reran with just 5 processes reniced from -10 to -5. On my >> system they were: events, khelper, kblockd, aio and reiserfs. In >> addition, I reniced loop0 from -20 to -5. > >> One major problem: this `nice --20' hack affects every thread, not >> just the critical realtime ones. That's not what we want. Audio >> applications make very conscious choices which threads run with high >> priority and which do not. > > how much did this problem affect your test? Could the source of the 500 > msec delays be the non-highprio components of the test that somehow > became nice --20? Some interference is definitely possible. But, the test does not involve any graphical interface, so I'd expect that to be small. Looking at jack_test3_client.cpp, the main thread just does a sleep() while the process cycle is running. Still, it's hard to be sure. Probably, the best way to tell would be patching JACK so it uses nice(-20) instead of pthread_setschedparam() for the realtime threads. As a hack, that looks easy. I'll build a working directory with just that change, so we can experiment with it better. -- joq - 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/