[openib-general] openIB question

Dotan Barak dotanb at mellanox.co.il
Tue Aug 15 23:17:50 PDT 2006


Hi and welcome John  
:) 

On Wednesday 16 August 2006 09:01, john t wrote:
> Hi,
> 
> I am new to openIB and have some questions.
> 
> - A QP has two work queues, send work queue and receive work queue. When
> host A sends a data buffer to host B using a QP (RC), I want to know if data
> is copied into the send work queue of host A and then into the receive work
> queue of host B or is it only the address of data buffer that is pushed into
> the send work q and receive work q.
If you use RC QP and send the data using the SEND opcode, if you'll get a completion
(with good status) in the sender, that means that the data was written in the receiver buffer.
> 
> - I want to develop an application (using uverbs or any such appropriate
> tool) that uses raw datagrams. Basically I want to send an IB packet from
> host A to host B and receive the entire IB packet (along with headers +
> data) at host B. Is such a thing supported in openIB? Is there any example
> which I can look at?
In IB, you won't see the various headers (expect in UD QPs, in which you will get the GRH).

You can look at the example in the following url:
 https://openib.org/svn/gen2/trunk/src/userspace/libibverbs/examples/rc_pingpong.c

> regards,
> John T
> 


Dotan




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