On Sep 11, 2018, at 10:46 AM, Benjamin Brock 
<br...@cs.berkeley.edu<mailto:br...@cs.berkeley.edu>> wrote:

Thanks for your response.

One question: why would RoCE still requiring host processing of every packet? I 
thought the point was that some nice server Ethernet NICs can handle RDMA 
requests directly?  Or am I misunderstanding RoCE/how Open MPI's RoCE transport?

Sorry, I missed your follow-up question.

There’s nothing that says that RoCE *must* be implemented in the NIC.  It is 
entirely possible to write a host-side kernel driver to implement the RoCE 
protocol.  My point was that if you were to do this, you wouldn’t have any of 
the benefits that people expect with RoCE, but the protocol would work just 
fine.  Similar to how you can write a VERBS implementation over DPDK and run 
the entire protocol in user space (https://github.com/zrlio/urdma).  While I 
haven’t tested the urdma package, both the Intel 82599 and ENA support DPDK, so 
if what you’re looking for is a VERBS stack, that might be one option.  
Personally, I’d just use Open MPI over TCP if Open MPI is your goal, because 
that sounds like a lot of headaches in configuration.

Brian
_______________________________________________
users mailing list
users@lists.open-mpi.org
https://lists.open-mpi.org/mailman/listinfo/users

Reply via email to