From mboxrd@z Thu Jan 1 00:00:00 1970 From: Esben Nielsen Subject: Re: Which version of preempt_realtime to use? Date: Thu, 22 Jan 2009 08:40:29 +0100 Message-ID: <1232610029.26807.8.camel@localhost.localdomain> References: <1232366467.31686.10.camel@localhost.localdomain> <49748567.30201@osadl.org> <4974E686.60105@hedrich-winders.com> Reply-To: esn@terma.com Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Carsten Emde , linux-rt-users@vger.kernel.org To: mell@hedrich-winders.com Return-path: Received: from asgaard.lystrup.terma.com ([193.163.1.112]:52213 "EHLO asgaard.terma.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753929AbZAVHoJ convert rfc822-to-8bit (ORCPT ); Thu, 22 Jan 2009 02:44:09 -0500 In-Reply-To: <4974E686.60105@hedrich-winders.com> Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Mon, 2009-01-19 at 21:45 +0100, J=C3=BCrgen Mell wrote: > > > > Esben, > > > > =20 > >> I am going to suggest that we use preempt_realtime for a _real_ pr= oject > >> (i.e. costumers will depend on it). We will run on standeard x86 (= maybe > >> x86_64) hardware and will only need serial interfaces for realtime > >> purposes. Security is not an issue. Which version of preempt_realt= ime > >> should I pick? > >> =20 > > The latest and greatest *and* most stable version is 2.6.24.7-rt26.= As > > far as I know (but maybe others know better), there are no unresolv= ed > > issues with this "Latest Stable". The kernel release 2.6.24 may not > > contain sufficient architecture support for PPC and ARM, but the la= rge > > majority of x86 based processors and chipsets is well supported. > > > > Please report, if anything does not work as expected. > > =20 > The only thing which is missing for me from the 2.6.24.7-rt series is > the patch > "x86-fpu-fix-config_preempt-y-corruption-of-application-s-fpu-stack.p= atch" > , GIT commit > 870568b39064cab2dd971fe57969916036982862 from mainline 2.6.25. This > might cause trouble with applications which are using floating point > arithmetics. Otherwise I am using the 2.6.24.7-rt series on a machine > control for a 16 axes machine and it is working mostly well. There ar= e > only some points where I get big delays (up to some milliseconds) wit= h > my timer routine, where normally delays are below 50 microseconds. Up= to > now I could not find the application ( X ??) which is causing this. >=20 > Bye, > J=C3=BCrgen >=20 Which GIT-tree are you refering to? Is there at all an up-to-date GIT repository with preempt realtime? Esben -- To unsubscribe from this list: send the line "unsubscribe linux-rt-user= s" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html