From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 26 May 2002 06:08:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 26 May 2002 06:08:22 -0400 Received: from [80.120.128.82] ([80.120.128.82]:19716 "EHLO hofr.at") by vger.kernel.org with ESMTP id ; Sun, 26 May 2002 06:08:21 -0400 From: Der Herr Hofrat Message-Id: <200205260913.g4Q9DPT20434@hofr.at> Subject: Re: patent on O_ATOMICLOOKUP [Re: [PATCH] loopable tmpfs (2.4.17)]y In-Reply-To: <20020525204542.A10392@stm.lbl.gov> from David Schleef at "May 25, 2002 08:45:42 pm" To: David Schleef Date: Sun, 26 May 2002 11:13:25 +0200 (CEST) CC: Larry McVoy , Karim Yaghmour , Larry McVoy , Wolfgang Denk , linux-kernel@vger.kernel.org X-Mailer: ELM [version 2.4ME+ PL60 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > > > > > > There was one more match that was publicly claimed as copying by > > > the maintainer of RTLinux -- a few fields in the scheduler structure. > > > The script caught those, too, once I set the threshhold down to 3 > > > lines, which also picked up hundreds of mismatches. > > > > Good luck making that stick in court. First of all, the RTAI guys have > > admitted over and over that RTAI is a fork of the RTLinux source base. > > Paolo (the maintainer) hasn't. I (the second largest contributor) > hasn't. I understand why others talk about RTAI and RTLinux forking, > since the _projects_ forked, and the _ideas_ forked, but the _code_ > was always separate. At some point, a person gives up trying to > argue the point, and just says "it forked". But when you get down > to brass tacks, there was no code fork, because there was never one > code base. > > There was some sharing of code in the beginning, typically code that > was sent to the RTLinux mailing list by third parties. In that case, > the code was copyrighted by the individual. The fact that it later > showed up in RTLinux as "copyright VJY associates" does not change > the fact that Paolo got it from the original author. > david - you know the code. rtai-24.1.6a/fifo/rtai_fifos.c:line 25-31: */ ACKNOWLEDGEMENT NOTE: besides naming conventions and the idea of a fifo handler function, the only remaining code from RTL original fifos, as written and copyrighted by Michael Barabanov, should be the function "check_blocked" (modified to suite my style). However I like to remark that I owe to that code my first understanding of Linux devices drivers (Paolo Mantegazza). /* in rtai-1.6:oldfifos/rtai_fifos.c:line 1-9: /* Modification of RTL-FIFO devices by Paolo Mantegazza */ /* The original RTL_FIFOS are developped and copyrighted by Michael */ /* Barabanov, 1997, who derived them from fs/pipe.c in Linux, which is in */ /* turn copyrighted with "Copyright (C) 1991, 1992 Linus Torvalds". */ /* This modified version is for use with the RTAI module. It works in the */ /* same way as its original counterpart, but now you can chose either a */ /* task queue for bottom halves or an immediate wake up, plus assigning a */ /* static user buffer. */ /* See functions: rtf_create_using_bh and rtf_create_using_bh_and_usr_buf. */ In my opinion it is obvious that the RT comunity that was RTLinux and RTAI for quite a while was "stealing" ideas and code from each other - and that is a very good thing to happen in GPL'ed environments, there was for a long time one mailing list and that was being shared in a productive manner by both groups. The fact that the two groups splitt up and are fighting each other is what is really hurting both sides a lot and probably also hurting Linux in the market that has interest in hard-realtime. hofrat