On 29/11/18 - 14:59:36, Eric Dumazet wrote: > On Thu, Nov 29, 2018 at 2:47 PM Christoph Paasch <cpaa...@apple.com> wrote: > > > Indeed, the UDP-stack is not fully 4-tuple ready. > > > > > > What are your thoughts on getting it there? > > This would request an additional lookup, and heavy duty servers using > non connected sockets > would pay the price for an extra lookup for each incoming packets.
Indeed. But I'm sure we can do it such that those servers don't pay a cost. E.g., with a jump-label that would only be set when one does a "wait-for-connect" and only these sockets end up in that 4-tuple hash-table. > DNS servers and QUIC servers would not like that, since they have better use > of a single (unconnected) UDP socket per cpu/thread. I'm actually wondering, how are you doing Quic connection migration when having a single unconnected UDP socket per CPU? That would involve quite some cross-CPU communication, no? Except if something else is steering the different UDP-flows that belong to the same Quic connection to the right CPU... Christoph > > > > > > Should be doable by simply using a similar approach as TCP, no? Any caveats > > you see with that? > > > > Then, when one sets the "wait-for-connect"-flag we would add the socket to > > the hash-table only at connect()-time also addressing the cache-line miss > > you mentioned above. > > Sure.
