From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 20 Sep 2001 23:17:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 20 Sep 2001 23:17:49 -0400 Received: from tisch.mail.mindspring.net ([207.69.200.157]:47153 "EHLO tisch.mail.mindspring.net") by vger.kernel.org with ESMTP id convert rfc822-to-8bit; Thu, 20 Sep 2001 23:17:37 -0400 Subject: Re: [PATCH] Preemption Latency Measurement Tool From: Robert Love To: Dieter =?ISO-8859-1?Q?N=FCtzel?= Cc: Oliver Xymoron , Andrea Arcangeli , Roger Larsson , linux-kernel , ReiserFS List In-Reply-To: <200109202252.f8KMqLG17327@zero.tech9.net> In-Reply-To: <200109202252.f8KMqLG17327@zero.tech9.net> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT X-Evolution-Format: text/plain X-Mailer: Evolution/0.13.99+cvs.2001.09.20.15.42 (Preview Release) Date: 20 Sep 2001 23:17:28 -0400 Message-Id: <1001042255.7291.39.camel@phantasy> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2001-09-20 at 18:51, Dieter Nützel wrote: > > Does your audio source depend on any files (eg mp3s) and if so, could they > > be moved to a ramfs? Do the skips go away then? > > Good point. > > I've copied one video (MP2) and one Ogg-Vorbis file into /dev/shm. > Little bit better but hiccup still there :-( As I've been saying, the problem really shouldn't be disk I/O. I would think (and really hope) the readahead code can fit a little mp3 in memory. Even if not, its a quick read to load it. The continued blips you see are caused by something, well, continual :) > dbench 16 > Throughput 25.7613 MB/sec (NB=32.2016 MB/sec 257.613 MBit/sec) > 7.500u 29.870s 1:22.99 45.0% 0+0k 0+0io 511pf+0w > > Worst 20 latency times of 3298 measured in this period. > usec cause mask start line/file address end line/file > 11549 spin_lock 1 678/inode.c c01566d7 704/inode.c A single 11ms latency is not bad. Again, this looks OK. > ******************************************************* > > dbench 16 + renice artsd -20 works > GREAT! > > ******************************************************* Great :) > dbench 32 and above + renice artsd -20 fail > > Writing this during dbench 32 ...:-))) > > dbench 32 + renice artsd -20 > Throughput 18.5102 MB/sec (NB=23.1378 MB/sec 185.102 MBit/sec) > 15.240u 63.070s 3:49.21 34.1% 0+0k 0+0io 911pf+0w > > Worst 20 latency times of 3679 measured in this period. > usec cause mask start line/file address end line/file > 17625 spin_lock 1 678/inode.c c01566d7 704/inode.c What do you mean failed? -- Robert M. Love rml at ufl.edu rml at tech9.net