From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 25 May 2002 05:05:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 25 May 2002 05:05:45 -0400 Received: from mailout10.sul.t-online.com ([194.25.134.21]:32488 "EHLO mailout10.sul.t-online.com") by vger.kernel.org with ESMTP id ; Sat, 25 May 2002 05:05:44 -0400 Subject: RTAI/RtLinux From: Erwin Rol To: linux-kernel@vger.kernel.org Cc: RTAI users Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-AZQ/RHaCt8Lrh1ESRgWI" X-Mailer: Ximian Evolution 1.0.5 Date: 25 May 2002 11:05:32 +0200 Message-Id: <1022317532.15111.155.camel@rawpower> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --=-AZQ/RHaCt8Lrh1ESRgWI Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Normally I am not subscribed to the kernel list, but after a msg from Karim that there was a "fight" going on about RTAI I read the archives and decided that it was important enough to join the discussion. Both Linus and Larry seem to be not very interested in hard-realtime Linux additions, this is OK. I mean everybody has his interests and with so many Linux users and developers you can't all focus on the same thing. But we (RTAI developers, which include Karim and myself) have decided to focus on hard-realtime extensions to Linux. And it is than always very motivating to hear nobody gives a f*ck about your work or problems, because "hey, you don't have a business model that makes sense anyway" For example, first there is said that there is no userspace hard-realtime, than Karim corrects that, than there is said that a userspace program that uses mlockall is actually a module: with other words be quiet and go sit in the corner. This seems the same as what happened with FSMLabs, first they explain why userspace hard-realtime is crap, and now they have implemented it them self and explain how good it is.=20 We have had several discussions with FSMLabs about userspace hard-realtime and asked for comments on for example the following situation. - When i write a RTAI module, that changes the sched_setparam in such a way that SCHED_FIFO and SCHED_RR are now hardrealtime. Than a binary program that runs on a computer with the RTAI kernel-module loaded violates the patent, and on a computer that doesn't have it loaded it doesn't violate the patent.=20 - needless to say we never even got a reply on questions like these. When you have to believe FSMLabbs, you are not allowed to use non-GPL software on a system that has a RTAI module loaded, according to Eben Mo There was also asked about the possibility (and even some person on the RTAI list started such a project) to have a *BSD version of RTAI, well the answer is simply NO. since *BSD will not accept GPL kernel code, and the RTLinux patent doesn't allow no GPL implementations there will be no free *BSD with this type of hard-realtime. Of course you can buy the FSMLab version, but than you can just as well buy a true RTOS, like VxWorks. Also apparently there is the idea that all RTAI developers want to become rich by getting the patent out of the way and sell RTAI. I know you all know this is simply not true, like most Linux hacker we spend a large part of our free time to give the real-time community a usable piece of software where they normally have to pay for.=20 So please don't stamp us as some money sucking bastards that shouldn't be allowed to use Linux in the first place. I just hope the linux developers are smart enough to not accept the RTLinux into the main kernel, cause someday someone might come up with the idea to write something that allows to have userspace programs to be hard-realtime, and than you have to stop allowing non GPL userspace programs, like for example GLIB( which is LGPL).=20 - Erwin Rol , RTAI Developer --=-AZQ/RHaCt8Lrh1ESRgWI Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQA871PcILu3T9PlUj8RAsRqAJ0XH2NVLCQQt5kiC2D+KI6K1lDRQACgxpra BhKPbehgD71MDQatyGhZQJg= =wQtg -----END PGP SIGNATURE----- --=-AZQ/RHaCt8Lrh1ESRgWI--