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Does SCO own read-copy-update?Does SCO own read-copy-update?Posted Jun 13, 2003 14:40 UTC (Fri) by StevenCole (guest, #3068)Parent article: Does SCO own read-copy-update? Read-copy-update technology is covered by US Patent 5,442,758 "Apparatus and method for achieving reduced overhead mutual exclusion and maintaining coherency in a multiprocessor system utilizing execution history and thread monitoring".
This patent lists the Evidently, on 08/15/1999, that patent expired due to non-payment of a maintenance fee, but on 05/31/2000 a petition to accept late payment of the fee was filed, and on 06/14/2000 that petition was granted. For additional information on this patent, go to the USPTO Patent Full-Text and Image Database. Select Patent Number in Field 1 and enter 5442758 in Term 1. If SCO's code is using RCU, they may be infringing on that patent.
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Does SCO own read-copy-update? Posted Jun 13, 2003 15:08 UTC (Fri) by freeio (guest, #9622) [Link] Sequent is now part of IBM, is it not? One has to assume that the Monterey agreements included cross-licensing of patents between SCO and IBM, and so SCO is probably covered in its use of the technique described in the patent.But then again, since IBM is supporting Linux, there is no problem with Linux using the technique (as opposed to the actual code) either. If IBM contibuted code that used the technique (under GPL) then the technique is OK for that use even if the exact implementation were not. Marty
Does SCO own read-copy-update? Posted Jun 13, 2003 15:25 UTC (Fri) by shahms (subscriber, #8877) [Link] Of course, even if the Monterey agreements included cross-licensing agreements suing for breach of contract certainly puts them in a dubious position wrt those other agreements. Assuming the Linux RCU code in question was copied from SCO, doesn't the existance of this patent mean that, either way, SCO loses? (I'd pretty much assumed that anyway, even if SCO wins the lawsuit it means they exist as a viable entity for what, another two years?)If SCO wins the lawsuit on copyright infringement, the RCU code has to be removed from Linux, whoo, it can be rewritten (the GPL doesn't prevent patented algorithms from being used, it just states that the GPL implementation of that algorithm must be "freely redistributable"). But SCO is SOL, given that I don't think IBM is going to say "we just lost a lawsuit to you, so we're feeling inclined to just let you use an algorithm we have a patent on without paying for it" more likely they'll say: "you're free to use the GPL implementation, but if you do, you'd better GPL UnixWare or we'll sue *you* for copyright and patent infringement"
IBM owns Sequent (and the patent), employs one of two inventors Posted Jun 13, 2003 15:43 UTC (Fri) by emk (subscriber, #1128) [Link] IBM apparently bought Sequent for $810 million dollars. Therefore, if Sequent is the assignee for the RCU patent, IBM owns the patent. IBM also employed McKenny, one of the two inventors of RCU. Since RCU was published and patented, SCO can hardly claim RCU is a trade secret. And since IBM appears to control the RCU patent, SCO doesn't have any obvious way to claim patent infringement. This leaves charges of copyright infringement. For IBM to have infringed on SCO copyrights, SCO would need to have implemented a technique patented by Sequent, and given the code to Sequent. This is possible, but hard to believe. It's certainly more plausible that Sequent wrote the RCU code themselves and later contributed it to Project Monterey, from where it migrated into SCO's code base. But there's no way to tell. It's also possible that every Project Monterey participant signed a contract with SCO, handing over control of any patents and copyrights for work they developed independently. But again, this is hard to believe. In any event, the original RCU diffs added only 1,811 lines to the kernel, including copyright notices and documentation. A top-notch C hacker working in user space can average 250 lines/day on tricky algorithms (I've seen it done), so we're looking at a few engineer-months, maximum. This first concrete allegation of wrongdoing looks pretty marginal. I was expecting something less ambiguous; perhaps a few hundred lines of random subroutines from the SVR4 code, contributed by somebody who didn't understand the responsibilities of a SVR4 license. If SCO wants to claim they own the RCU code, they'd better be prepared to show they actually wrote it, and didn't just misplace the copyright notices when borrowing some of Sequent's code.
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