Date: Wed, 15 Mar 2006 10:45:01 +0000 (GMT) From: Robert Watson <rwatson@FreeBSD.org> To: net@FreeBSD.org Subject: netatm: plan for removal unless an active maintainer is found (fwd) Message-ID: <20060315104419.F5861@fledge.watson.org>
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FYI: An e-mail thread relating to the following is taking place on the arch@ mailing list. Please follow up to that list with any comments/discussion. Robert N M Watson ---------- Forwarded message ---------- Date: Wed, 15 Mar 2006 01:00:57 +0000 (GMT) From: Robert Watson <rwatson@FreeBSD.org> To: arch@FreeBSD.org Subject: netatm: plan for removal unless an active maintainer is found For some time now, the FreeBSD Project has been carrying around at least three ATM stacks: - netatm - HARP, the Host ATM Research Platform - netnatm - A fairly minimal socket<->virtual circuit ATM wrapper for ATM device drivers - ngatm - NetGraph ATM framework For a variety of reasons, it would be desirable to do a bit of pruning of ATM stacks. In my previous conversations with Harti and Bruce, the conclusion has generally been that ngatm and netnatm provide almost all functionality provided by netatm and more, but in modern, and actively maintained, frameworks. The main motivator for pruning has to do with the SMP network stack work: we're reaching the point, discussed on a number of occasions previously on this mailing list, where jettisoning unmaintained network stack components that are unable to run MPSAFE, is highly desirable. This would allow us to remove compatibility shims that are increasingly burdonsome in terms of performance and complexity. Another aspect of this has to do with upcoming changes to the socket and pcb code, which will require maintainers of protocols to do a small but non-trivial amount of work to update protocols to fit the new socket behavior. Right now, almost all other sections of the network stack have active maintainers who are able to do this work, both development and testing, except for the netatm code. We've reached the point where continuing to carry around a third ATM stack is a significant impediment to continued work on network stack performance and reliability work. This should not be a surprise to anyone who reads this mailing list regularly, since I sent out e-mail on this very topic on July 18, 2005, warning that netatm (and several other components) were at risk as unmaintained but substantial network stack components. The proposal is as follows: In order to begin to merge revised socket/pcb code, required to fix a number of current races manifesting in the TCP code under load, and required for breaking out the tcbinfo lock which is a significant bottleneck in high performance TCP and multi-processor TCP scalability, I will disconnect netatm and dependent components from the build on April 1, 2006. At that point, I will merge updated socket and pcb reference counting. If a maintainer has not been found who can update and adequately test the netatm code for the new socket/pcb interfaces by June 30, 2006, the netatm code will be deleted from CVS HEAD (although remain available in Attic should someone turn up later). I'm happy to provide some first cut patches for any maintainer that arrives that do implement the changes, but I am unable to test them, and suspect they will be significant deficient for this reason, so will not commit them myself. This will leave us with at least two quite functional ATM implementations. Please let me know if netatm is critical to your work and you will be able to work with me to get netatm into shape. For someone already familiar with the netatm implementation and set up to perform ATM network testing, this should be straight forward and I'm happy to help in any way I can. If you are available to act in this role, my recommendation would be that we meet at BSDCan in Ottawa this May to discuss long term maintenance directions, and so that we can work out a plan for handling SMP behavior for netatm, as well as its integration with the socket code. Robert N M Watson _______________________________________________ freebsd-arch@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-arch To unsubscribe, send any mail to "freebsd-arch-unsubscribe@freebsd.org"
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