From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265605AbUAMTs5 (ORCPT ); Tue, 13 Jan 2004 14:48:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265611AbUAMTs5 (ORCPT ); Tue, 13 Jan 2004 14:48:57 -0500 Received: from x35.xmailserver.org ([69.30.125.51]:25799 "EHLO x35.xmailserver.org") by vger.kernel.org with ESMTP id S265605AbUAMTsz (ORCPT ); Tue, 13 Jan 2004 14:48:55 -0500 X-AuthUser: davidel@xmailserver.org Date: Tue, 13 Jan 2004 11:48:58 -0800 (PST) From: Davide Libenzi X-X-Sender: davide@bigblue.dev.mdolabs.com To: Roger Larsson cc: Takashi Iwai , Daniel Phillips , Steven Newbury , Linux Kernel Mailing List Subject: Re: SCHED_SOFTRR patch (memory lock?) In-Reply-To: <200308072005.07017.roger.larsson@skelleftea.mail.telia.com> Message-ID: 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 On Thu, 7 Aug 2003, Roger Larsson wrote: > On Thursday 07 August 2003 18.31, Takashi Iwai wrote: > > At Thu, 7 Aug 2003 16:59:03 +0100, > > > > Daniel Phillips wrote: > > > > 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. > > > > > > According to me, this should not happen, since your cpu usage is well > > > below what is supposed to be the cutoff for the realtime slice. I've > > > only seen one report like yours, where SOFTRR isn't working as intended. > > > On the other hand, I've missed a lot of lkml traffice lately, so there > > > could be more. > > > > looking at the source code of xmms and found that xmms OSS output > > plugin behaves differently if the process is SCHED_RR. > > when xmms is started with SCHED_RR, it won't create an (another) audio > > thread. perhaps this explains also the difference found in some > > cases. > > > > well, i'm not 100% sure about this theory, now needs to practice :) > > please try to turn off the check of SCHED_RR in > > xmms/Output/OSS/audio.c, something like: > > > > realtime = xmms_check_realtime_priority(); > > > > replaced with > > > > realtime = 0; > > Another possibility - will XMMS lock its memory from swapping when running as > root? (Or are there any special allocation/IO rule for root?) Gee, it was 100F last time I saw this thread :-) Yes, xmms behave in two completely different ways depending on the fact that it is or it is not running RR. With RR it writes directly to the dsp, while w/out it creates a thread that handles an output buffer. Then thread then does write to the dsp when the buffer has something to be written. - Davide