[openib-general] [cma] the private data length that arrives with the event RDMA_CM_EVENT_CONNECT_REQUEST is false

[Dotan Barak]

Roland Dreier wrote:
>     Dotan> The problem is that the private_data_len in the second side
>     Dotan> (receiver) is not equal to the sent data (length).
>
> How do you expect the private data length to be passed from one side
> to the other?  There is no such field in the CM protocol.
>
> The only thing the RDMA CM can do is pass the maximum possible private
> data length to the passive consumer.
>
>  - R.
>   
You are right, the CM should support only private data (according to the 
IB spec chapter 12).
The CMA implementation in the gen2 have the attribute private_data_len 
in the rdma_cm_event structure.

So, what is the purpose of private_data_len (in the event structure)?

thanks
Dotan