From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 18 Sep 2001 19:30:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 18 Sep 2001 19:30:14 -0400 Received: from maynard.mail.mindspring.net ([207.69.200.243]:61465 "EHLO maynard.mail.mindspring.net") by vger.kernel.org with ESMTP id ; Tue, 18 Sep 2001 19:30:05 -0400 Subject: Re: Feedback on preemptible kernel patch From: Robert Love To: Roger Larsson Cc: Dieter =?ISO-8859-1?Q?N=FCtzel?= , Linux Kernel List In-Reply-To: <200109181822.f8IIMv618968@mailg.telia.com> In-Reply-To: <200109140302.f8E32LG13400@zero.tech9.net> <1000530869.32365.21.camel@phantasy> <20010918040550Z273827-761+10122@vger.kernel.org> <200109181822.f8IIMv618968@mailg.telia.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit X-Mailer: Evolution/0.13.99+cvs.2001.09.18.07.08 (Preview Release) Date: 18 Sep 2001 19:31:28 -0400 Message-Id: <1000855890.19833.51.camel@phantasy> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2001-09-18 at 14:18, Roger Larsson wrote: > Do you run with the playback process reniced -N? > It should really run with a low SCHED_FIFO or SCHED_RT policy. > But renicing it with a negative value gives some of the benefits... > (but you need to run as root) > In addition to this the program might need to lock its pages down - the > only thing I can think of that could cause several seconds delay would > be if it has been swapped out... Certainly giving it a higher priority should improve results (especially with preemption), but the application should receive a fair amount of process attention as it is, as it is TASK_RUNNABLE at all times and the disk I/O should be routinely preempted. I am interested how much renicing it helps, though. Now, if it has to swap pages, that is a very good point. I tend to blame this, or perhaps something with a long held lock (the audio driver?) for the blips. Its so hard to tell swap/VM issues now with all the VM work, sadly...:) -- Robert M. Love rml at ufl.edu rml at tech9.net