From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750759AbWCGWKa (ORCPT ); Tue, 7 Mar 2006 17:10:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751380AbWCGWKa (ORCPT ); Tue, 7 Mar 2006 17:10:30 -0500 Received: from viper.oldcity.dca.net ([216.158.38.4]:12782 "HELO viper.oldcity.dca.net") by vger.kernel.org with SMTP id S1750759AbWCGWKa (ORCPT ); Tue, 7 Mar 2006 17:10:30 -0500 Subject: Re: [opensuse-factory] Re[2]: 2.6.16 serious consequences / GPL_EXPORT_SYMBOL / USB drivers of major vendor excluded From: Lee Revell To: Silviu Marin-Caea Cc: opensuse-factory@opensuse.org, linux-kernel@vger.kernel.org In-Reply-To: <200603070942.31774.silviu_marin-caea@fieldinsights.ro> References: <200603070942.31774.silviu_marin-caea@fieldinsights.ro> Content-Type: text/plain Date: Tue, 07 Mar 2006 17:10:21 -0500 Message-Id: <1141769422.767.99.camel@mindpipe> Mime-Version: 1.0 X-Mailer: Evolution 2.5.92 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2006-03-07 at 09:42 +0200, Silviu Marin-Caea wrote: > On Monday 06 March 2006 14:47, s.schmidt@avm.de wrote: > > > Even though people might do realtime DSP things in user space with Linux > > and soft modems might work pretty well in userspace, in the case of Fax G3 > > an extremely short latency is required. > > So basically we have to choose between: > > 1. keeping a stable open source kernel and sticking to the principles that got > Linux where it is now > > and > > 2. Fax G3 > > Umm... Extremely short, consistent latency is also required to use a Linux box as a live audio effects processor and thousands of people do that. It works extremely well, is used by numerous professionals, and no one has ever seriously proposed moving it to the kernel. The POSIX realtime APIs were designed for exactly this kind of application. If they are doing serious realtime DSP then they should get better results in userspace anyway, because they get to use the floating point unit which isn't allowed in the kernel. I suspect you last tried it in the 2.4 or early 2.6 era when patching the kernel was required to get decent latency. Lee