[openib-general] Reuse pd amd mr

[Dotan Barak]

john t wrote:
> Hi Dotan,
>  
> This may be a very basic question. When u said "QPs can listen/send 
> the packets on any port and write to the same MR", does it mean QPs 
> can listen/send packets to any port on the same HCA or to also ports 
> on different HCA ?
You are right, i wasn't clear enough (sorry)...

What i  meant was that you can work with more than one QP in an HCA,
each QP can send/recv messages on a different port (every QP is working 
with only one port).

A QP is a resource in the HCA, hence a QP in HCA1 cannot listen/send 
packets to the port of HCA2.
If you wish, your SW can handle all of the HCAs: you can open a QP for 
every port in every HCA( total QPs:  #HCAs * #Ports ).

i hope i was more clear this time ...
Dotan



>
>  
> On 9/18/06, *Dotan Barak* <dotanb at dev.mellanox.co.il 
> <mailto:dotanb at dev.mellanox.co.il>> wrote:
>
>     Hi john.
>
>     john t wrote:
>     > Hi
>     >
>     > I have two HCA cards each having one port. I want to use same
>     memory
>     > buffer to store packets arriving on the two ports. Can I do this,
>     > meaning can I use same pd (protection domain) and mr (memory
>     > registration) for the two QPs (one QP on each port), though the
>     > context ( i.e. ib device) for each QP is different?
>
>     if the context is different how can you create 2 QPs using the
>     same PD?
>     The context is a driver abstraction and the HCA is not aware of it ...
>
>     anyway, if you have 2 QPs and 1 MR which are in the same PD, the
>     QPs can
>     listen/send the packets on any port and write to the same MR
>     (in different address of course, the order of the packet arrival in
>     those QPs is "random" ...)
>
>     Dotan
>
>