[openib-general] [RMPP] RFC on retry sending RMPP MADs

[Sean Hefty]

After studying how to send RMPP MADs, there's not an efficient way for 
the MAD layer to resend a segment in case of a lost packet or ACK.  A 
simple solution would be to add a retry counter to ib_send_wr.  This 
would instruct the MAD layer to retry a send a specific number of times 
until an ACK is received.  (An alternate solution would be to retry a 
fixed number of times.)

This opens the potential of using the retry counter not just with RMPP, 
but also for normal request-response MADs, allowing for automatic 
linear retries.  We wouldn't have to implement this support, but the 
API would be there.

For the case of supporting RMPP, does anyone see any other 
alternatives?  Any other comments?

- Sean