> I'm personally not a big fan of TSO or TOE. They both add a lot of > complexity > to the network stack, and have other downsides. The *best* way to solve > these problems is to engineer technologies to use larger packet sizes. Even > at 9k (or better yet 16k) the advantages of these offload schemes is > vanishingly small. (Though if a TOE can do zero-copy receive, this is a win > over what currently exists, but I think there are other ways to do that as > well.) The Linux kernel may not be able to do too much to encourage > deployment of larger MTUs, but NIC vendors probably can.
Hmm - but is a 9k or 16k packet on the wire not equivalent to a micro burst? (actually it is not that micro compared to 1.5k packets). At least against burstiness they don't help and make things even worse because the bursts cannot be split up anymore. Actually I think there is still much potential to lower the CPU overhead of individual packets (e.g. by optimizing the cache latencies of fetching headers and writing TX rings and using per CPU MSIs aggressively for TX completion interrupts). So it might be possible to do much better even with small packets. Even for TX. For RX there is even more relatively low hanging fruit given some NIC support (however it will need some limited amount of state in the NIC) -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
