On Sat, 2006-07-01 at 16:26 +0200, Andi Kleen wrote: > On Saturday 01 July 2006 01:01, Tom Tucker wrote: > > On Fri, 2006-06-30 at 14:16 -0700, David Miller wrote: > > > > > The TOE folks have tried to submit their hooks and drivers > > > on several occaisions, and we've rejected it every time. > > > > iWARP != TOE > > Perhaps a good start of that discussion David asked for would > be if you could give us an overview of the differences > and how you avoid the TOE problems.
Interesting thread, I hope someone replies to Andi's request. I've actually no real idea what RDMA, IWARP & TOE are, so I may be barking up completely the wrong tree here. If so, apologies. But it sounds like we're talking about technologies that offload some part of the network/transport layer processing to the interface device? And the primary objection to that is that it may bypass some of the cool features of the Linux stack? Stuff like iptables and ... what exactly? Presumably the reason why such offloading would be a Good Thing are to do with very high speed network processing, 10G ethernet and the like. Which sounds to me very like the way dedicated networking kit would do that. So if you have a device that needs to be a very high performance router, you dedicate it to that function and don't try to do clever per-packet or -flow processing at the same time. In the Cisco world, there's a network design approach where you consider your equipment in three 'layers', I think they call them the core, distribution and access layers, or something like that. The idea is that the core layer handles the real high speed stuff, you don't do anything much except routing/switching in there. The other layers aggregate flows for the core, if you need extra processing (firewalls etc) you do it somewhere in there. So, for example, the packet capture functions (sort of like tcpdump) don't work if fast switching is in use, which it would be in the core. Users accept these tradeoffs, because if you design it right you can do the extra processing on some other device in the outer layers. So perhaps there's a good argument to make that a Linux system with the right hardware could be considered a core device. Likely any place you have such a system it would be dedicated to just moving data as well as possible, and let other systems do the other stuff. You wouldn't want your server farm systems to also be your firewalls. Bottom line - these technologies seem to me to have a place in a well designed network. Just my 2c... - Andy > > -Andi > - > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to [EMAIL PROTECTED] > More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
