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 02:40:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 20 Sep 2001 02:40:44 -0400 Received: from paloma17.e0k.nbg-hannover.de ([62.159.219.17]:40105 "HELO paloma17.e0k.nbg-hannover.de") by vger.kernel.org with SMTP id ; Thu, 20 Sep 2001 02:40:38 -0400 Content-Type: text/plain; charset=US-ASCII From: Dieter =?iso-8859-1?q?N=FCtzel?= Organization: DN To: Robert Love , Roger Larsson Subject: Re: Feedback on preemptible kernel patch Date: Thu, 20 Sep 2001 08:40:56 +0200 X-Mailer: KMail [version 1.3.1] Cc: Linux Kernel List In-Reply-To: <200109140302.f8E32LG13400@zero.tech9.net> <200109181822.f8IIMv618968@mailg.telia.com> <1000855890.19833.51.camel@phantasy> In-Reply-To: <1000855890.19833.51.camel@phantasy> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Message-Id: <20010920064042Z274341-760+14433@vger.kernel.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Am Mittwoch, 19. September 2001 01:31 schrieb Robert Love: > 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. Nearly zero :-) > 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. System didn't go into swap during whole test, sorry. > Its so hard to tell swap/VM issues now with all the VM work, sadly...:) I point to the second;-) -Dieter