This is pretty interesting to me for IP-over-InfiniBand, for a couple of reasons. First of all, I can push multiple send requests to the underlying adapter in one go, which saves taking and dropping the same lock and also probably allows fewer MMIO writes for doorbells.
However the second reason this is useful is actually more interesting. Right now we request a send completion interrupt for every packet we send because most current IB adapters don't really have very good interrupt mitigation features. If we don't signal a send completion for every packet, then we might run into a situation where we don't get a completion for the last packet that gets sent and end up stalling the interface because the stack never gives us another packet to send. However, if I have a whole queue of packets passed to my xmit routine, then I only have to request a completion for the last packet in the list, which could potentially cut down on interrupts and completion processing a lot. - R. - 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
