From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264627AbUGMIaU (ORCPT ); Tue, 13 Jul 2004 04:30:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264635AbUGMIaT (ORCPT ); Tue, 13 Jul 2004 04:30:19 -0400 Received: from cantor.suse.de ([195.135.220.2]:61324 "EHLO Cantor.suse.de") by vger.kernel.org with ESMTP id S264627AbUGMIaP (ORCPT ); Tue, 13 Jul 2004 04:30:15 -0400 Date: Tue, 13 Jul 2004 10:30:13 +0200 Message-ID: From: Takashi Iwai To: Andrew Morton Cc: Paul Davis , albert@users.sourceforge.net, linux-kernel@vger.kernel.org, florin@sgi.com, linux-audio-dev@music.columbia.edu Subject: Re: desktop and multimedia as an afterthought? In-Reply-To: <20040712172458.2659db52.akpm@osdl.org> References: <1089665153.1231.88.camel@cube> <200407122354.i6CNsNqS003382@localhost.localdomain> <20040712172458.2659db52.akpm@osdl.org> User-Agent: Wanderlust/2.10.1 (Watching The Wheels) SEMI/1.14.5 (Awara-Onsen) FLIM/1.14.5 (Demachiyanagi) APEL/10.6 MULE XEmacs/21.4 (patch 15) (Security Through Obscurity) (i386-suse-linux) MIME-Version: 1.0 (generated by SEMI 1.14.5 - "Awara-Onsen") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org At Mon, 12 Jul 2004 17:24:58 -0700, Andrew Morton wrote: > > I am deeply skeptical about claims that CPU scheduler changes make any > difference. A scheduler change shouldn't improve responsiveness of > !SCHED_OTHER tasks at all, so perhaps there are application priority > inversion problems, or applications aren't setting SCHED_FIFO/RR correctly. > I do not know. Regarding the JACK problem, it seems that the incompatibility with NPTL (SCHED_INHERIT is default) did wrong. Taking a look through the thread, I feel that very different topics are argued in the single "desktop" problem, namely, the interactivity and the latency. The latter, the problem of real-time audio (e.g. JACK), must be irrelevant with the CPU scheduler. It can be fixed by detecting the too long critical sections, but the fix won't always improve the interactivity. OTOH, the interactivity can be, and should be improved somehow with tuning of CPU scheduler. However, even about this word, we discuss totally different meanings. For example, the GUI response and the fluent audio/video playback. The improvement of the former doesn't imply the improvement of the latter (often contradictorily)... -- Takashi Iwai ALSA Developer - www.alsa-project.org