[openib-general] max message size for IB_WR_SEND

[Dotan Barak]

Hi.

amit byron wrote:
> hi,
>
> if i evoke/call ib_post_send(IB_WR_SEND) with message
> size 512 bytes, the message gets received on the
> peer (second) node. the 2 nodes are connected point-to
> -point.
>
> but if message size is increased to 4096 bytes then
> second node receives the message; but message content
> is missing (empty).
>
> won't infiniband stack break down message in smaller
> chunks and assemble on peer node?
>
> thanks,
> Amit.
>   
Which transport type are you using?
if you are using a UD QP, then the answer is no.
for any other transport type, the answer is yes (the message is being 
break down to packets with the MTU side as specified in the QP context.

maybe you have a different problem in you code. did you check the 
completion status in both of the nodes?

Dotan