Il 11/04/2013 16:37, Michael S. Tsirkin ha scritto: > > pg1 -> pin -> req -> res -> rdma -> done > pg2 -> pin -> req -> res -> rdma -> done > pg3 -> pin -> req -> res -> rdma -> done > pg4 -> pin -> req -> res -> rdma -> done > pg4 -> pin -> req -> res -> rdma -> done > > It's like a assembly line see? So while software does the registration > roundtrip dance, hardware is processing rdma requests for previous > chunks.
Does this only affects the implementation, or also the wire protocol? Does the destination have to be aware that the source is doing pipelining? Paolo > > .... > > When do you have to stall? when you run out of rx buffer credits so you > can not start a new req. Your protocol has 2 outstanding buffers, > so you can only have one req in the air. Do more and > you will not need to stall - possibly at all. > > One other minor point is that your protocol requires extra explicit > ready commands. You can pass the number of rx buffers as extra payload > in the traffic you are sending anyway, and reduce that overhead.
