[openib-general] [PATCH 3/5 v3] 2.6.20 rdma/cma: allow early transition to RTS to handle lost CM messages

[Or Gerlitz]

Michael S. Tsirkin wrote:
>> To handle the case
>> where the connection messages are lost, a new API is added that users
>> may invoke to force a connection into the established state.
> 
> Just to clarify this point - what connecton messages can be lost?
> E.g. if the passive side does not get an RTU for a while, it will
> retry the REP, won't it?  Diagram 12.9.6 seems to indicate so:
> from REP Sent we should go to RTU timeout, Send REP and back to REP Sent.
> Is this implemented?

It handles the case where the first RX crosses the RTU which can happen 
when the RTU is lost but also without it being lost.

Indeed the passive side would resend the REP when a timeout expires but 
the patch allows the app to force the connection establishment **now** 
(ie have the CMA move the RC QP to RTS) and not go into queuing of RX-es 
etc till the RTU is lost, it also handles the case where all the RTUs 
are lost.

Or.