[ofa-general] Query on ibv_post_recv and IBV_SEND_INLINE

[Dotan Barak]

Hi.

Bharath Ramesh wrote:
> I have a question on using IBV_SEND_INLINE. From what I understand if I am
> using IBV_SEND_INLINE I technically neednt register the buffer with
> ibv_reg_mr as I dont need the L_Key. But still in the receiver end I
> would have to have the buffer registered to receive the inline data that
> has been posted. If I have an application where I am using a lot of
> small messages, then memory registration would be expensive. Is there
> any other option for receiving inline messages with out actually
> registering the receive buffer.
>   
The flag IBV_SEND_INLINE describe to the low level driver how the data 
will be read from the memory buffer
(the driver will read the data and give it to the HCA or the HCA will 
fetch the data from the memory using
the gather list).

The data on the wire for inline messages looks the same like data which 
was fetched by the HCA.

The receive side don't have any feature which can work with memory 
buffer without any registration.


thanks
Dotan