[ofa-general] [RFC] handling slow listeners in rdma_cm

[Sean Hefty]

I'm looking for input on different options for handling listeners in the rdma_cm
that are slow to respond to connection requests.

Some options (in no particular order):

* Expose a call similar to ib_send_cm_mra (rdma_ack_connect?).

* Adapt an existing call for this purpose (rdma_notify? rdma_listen?).

* Have the rdma_cm always send an MRA.

* Add code to the rdma_cm to queue MRA responses, which would be sent after a
specific timeout has occurred, if the connection had not yet already be accepted
or rejected.

* Add a call to the ib_cm to send an MRA, but only if a duplicate REQ is
received before the original REQ has been processed (ib_set_cm_mra?).

* Make the CMA_CM_RESPONSE_TIMEOUT a module parameter.

Any thoughts or comments?

- Sean