From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-1?Q?J=FCrgen_Mell?= Subject: Re: Which version of preempt_realtime to use? Date: Mon, 19 Jan 2009 21:45:58 +0100 Message-ID: <4974E686.60105@hedrich-winders.com> References: <1232366467.31686.10.camel@localhost.localdomain> <49748567.30201@osadl.org> Reply-To: mell@hedrich-winders.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: esn@terma.com, linux-rt-users@vger.kernel.org To: Carsten Emde Return-path: Received: from dispoweb.ifw.uni-hannover.de ([130.75.23.4]:36262 "EHLO ketschua.hedrich-winders.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753272AbZASU4S (ORCPT ); Mon, 19 Jan 2009 15:56:18 -0500 In-Reply-To: <49748567.30201@osadl.org> Sender: linux-rt-users-owner@vger.kernel.org List-ID: > > Esben, > > =20 >> I am going to suggest that we use preempt_realtime for a _real_ proj= ect >> (i.e. costumers will depend on it). We will run on standeard x86 (ma= ybe >> x86_64) hardware and will only need serial interfaces for realtime >> purposes. Security is not an issue. Which version of preempt_realtim= e >> should I pick? >> =20 > The latest and greatest *and* most stable version is 2.6.24.7-rt26. A= s > far as I know (but maybe others know better), there are no unresolved > issues with this "Latest Stable". The kernel release 2.6.24 may not > contain sufficient architecture support for PPC and ARM, but the larg= e > 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.pat= ch" , 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 are only some points where I get big delays (up to some milliseconds) with my timer routine, where normally delays are below 50 microseconds. Up t= o now I could not find the application ( X ??) which is causing this. Bye, J=FCrgen --=20 J=FCrgen Mell (Software-Entwicklung) mell@hedrich.com Tel.: +49-511-762-18226 http://www.hedrich.com =46AX : +49-511-762-18225 Mobil: +49-160-7428156 -----------------------------------------------------------------------= --------- HEDRICH winding systems GmbH An der Universit=E4t 2 (im PZH) D-30823 Garbsen (GERMANY) -----------------------------------------------------------------------= --------- Gesch=E4ftsf=FChrer: Karsten Adam, Markus Gerth, Friedrich Frech Handelsregister: Wetzlar, HRB 4768 Steuernr.: 020/235/20110 USt-IdNr.: DE 258258279 -----------------------------------------------------------------------= ---------=20 -- 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