[openib-general] Re: [PATCH] ib_mad: prevent duplicateoutstanding MADtransactions with same TID

[Sean Hefty]

Michael S. Tsirkin wrote:
>>>Host A sends an RMPP request message to host B with TID=3
>>>Host B sends an RMPP request message to host A with TID=3.
>>>Now if A generates an RMPP response it has TID=3.
>>>
>>>If B sends ACK, host A has no idea which transaction is being ACKed.
>>
>>Bah... can we distinguish which transaction is being ACKed by the response 
>>bit?
> 
> Are you talking about checking IB_MGMT_METHOD_RESP?
> 
> How is this different from what I proposed?

Yes - this is what you proposed.  I believe that it can work for ACKs since an 
ACK must match with a send.

> Wont this work for Abort/Stop as well?

Given the example above, with hosts A and B sending requests, if host B sends an 
abort, it's still unknown which transaction is being aborted, since neither the 
send or receive would have the response bit set.

- Sean