[openib-general] [PATCH 0/4] Dispatch communication related events to the IB CM

[Sean Hefty]

>Some things unclear to me:
>1. Is a user somehow *required* to call ib_cm_establish if he gets the event?
>   E.g. what about cma users?

A user is not required to call ib_cm_establish.  The patch fixes the issue where
CMA users receive a COMM_EST event, but do not have the ability to call
ib_cm_establish directly.  It does this by pushing COMM_EST event handling
directly to the IB CM.

>2. There are now two ways CM gets notified about Communication established
>   events - what happends if both the user calls ib_cm_establish, and CM
>   gets this directly?

The second call will fail due to an invalid state.  Note that this failure was
already possible, since an RTU could have been processed before the user could
have called ib_cm_establish.

>3. If I understand it correctly, CM does not yet know how to switch to the
>   alternate path for CM messages. So, is the patch still useful by itself,
>   or is it more of a framework preparatory work?

The patch is useful by itself for the COMM_EST event.  It is my intent that the
same infrastructure be used to notify the IB CM of path migration.  PATH_MIG
event handling is currently limited to mthca reporting path migration events to
the CM event handler.  The IB CM currently just ignores the event.  If it makes
it cleaner, I can remove the line from mthca that reports PATH_MIG events.

- Sean