From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S271045AbTG1U2X (ORCPT ); Mon, 28 Jul 2003 16:28:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S271033AbTG1U2W (ORCPT ); Mon, 28 Jul 2003 16:28:22 -0400 Received: from web60001.mail.yahoo.com ([216.109.116.224]:17811 "HELO web60001.mail.yahoo.com") by vger.kernel.org with SMTP id S271045AbTG1U1w (ORCPT ); Mon, 28 Jul 2003 16:27:52 -0400 Message-ID: <20030728202750.73149.qmail@web60001.mail.yahoo.com> Date: Mon, 28 Jul 2003 21:27:50 +0100 (BST) From: =?iso-8859-1?q?Steven=20Newbury?= Subject: SCHED_SOFTRR patch To: davidel@xmailserver.org Cc: linux-kernel@vger.kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org I personally see your SCHED_SOFTRR as the correct solution for multimedia applications. But as it is currently tuned I have been unable to get it to work adequately with a relatively undemanding program, XMMS. I say undemanding because XMMS only uses about 2-4% CPU time on my test machine (P3/933MHz) when playing mp3's. While testing SCHED_SOFTRR with XMMS I had to modify XMMS slightly since it usually checks for uid 0 before enabling SCHED_RR. Under 2.6.0-test1 based kernels I have experienced quite a lote of drop-outs with XMMS playing mp3's with a moderate load, however, when run as root (with SCHED_RR) I encountered no drop-outs at all. When using SOFTRR under I had very choppy playback when the machine was under load. It was a constant jittering more than intermittent drop-outs. I have been using a 2.6.0-test2-O10int based kernel in my latest tests. With 2.6.0-test2-O10int it is very hard to get drop-outs unless I run it with SCHED_SOFTRR! The jitteriness is gone but a moderate load causes dropouts, much like non SCHED_RR on 2.6.0-test1 based kernels. SCHED_RR still runs perfectly though. It could be that SCHED_SOFTRR is being too "tight" with the CPU time it is giving the Real-Time thread. I have tried various values for the SCHED_TS_KSOFTRR, MIN_SRT_TIMESLICE, MAX_SRT_TIMESLICE constants, but have been as yet unable to find values that produce a good result. The lattest.c program does show that SOFT_RR is working as does top which shows RT priority for XMMS. ===== Steve __________________________________________________ Yahoo! Plus - For a better Internet experience http://uk.promotions.yahoo.com/yplus/yoffer.html