From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756054AbZHYTSn (ORCPT ); Tue, 25 Aug 2009 15:18:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755940AbZHYTSm (ORCPT ); Tue, 25 Aug 2009 15:18:42 -0400 Received: from smtp4.ultrahosting.com ([74.213.175.253]:39429 "EHLO smtp.ultrahosting.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755927AbZHYTSl (ORCPT ); Tue, 25 Aug 2009 15:18:41 -0400 Date: Tue, 25 Aug 2009 15:18:13 -0400 (EDT) From: Christoph Lameter X-X-Sender: cl@gentwo.org To: Peter Zijlstra cc: Mike Galbraith , raz ben yehuda , riel@redhat.com, mingo@elte.hu, andrew motron , wiseman@macs.biu.ac.il, lkml , linux-rt-users@vger.kernel.org Subject: Re: RFC: THE OFFLINE SCHEDULER In-Reply-To: <1251227322.7538.1172.camel@twins> Message-ID: References: <1250983671.5688.21.camel@raz> <1251004897.7043.70.camel@marge.simson.net> <1251018551.3810.35.camel@raz> <1251012621.14003.71.camel@marge.simson.net> <1251025557.3810.65.camel@raz> <1251021133.14003.172.camel@marge.simson.net> <1251222993.7023.53.camel@marge.simson.net> <1251227322.7538.1172.camel@twins> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 25 Aug 2009, Peter Zijlstra wrote: > On Tue, 2009-08-25 at 14:03 -0400, Christoph Lameter wrote: > > On Tue, 25 Aug 2009, Mike Galbraith wrote: > > > > > I asked the questions I did out of pure curiosity, and that curiosity > > > has been satisfied. It's not that I find it useless or whatnot (or that > > > my opinion matters to anyone but me;). I personally find the concept of > > > injecting an RTOS into a general purpose OS with no isolation to be > > > alien. Intriguing, but very very alien. > > > > Well lets work on the isolation piece then. We could run a regular process > > on the RT cpu and switch back when OS services are needed? > > Christoph, stop being silly, this offline scheduler thing won't happen, > full stop. Well there are the low latency requirements still. Those need to be addressed in some form. Some of these ideas here are a starting point. > Its not a maintainable solution, it doesn't integrate with existing > kernel infrastructure, and its plain ugly. > > If you want something work within Linux, don't build kernels in kernels > or other such ugly hacks. Ok so how would you go about avoiding the OS noise which motivated the patches for the Offline scheduler?