Re: [RFC PATCH 1/5] IB/core: Add Core Capability flags to ib_device

Dave Goodell (dgoodell)
2015-05-11T22:26:06Z

On May 10, 2015, at 11:42 PM, ira.weiny <ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> wrote:

> On Tue, May 05, 2015 at 08:22:21PM +0000, Dave Goodell (dgoodell) wrote:
>>
>> In the case that usNIC is operating in UDP mode (which is the overwhelming majority of the cases), there is absolutely no additional protocol that ends up on the wire or headers in the user buffers besides UDP/IP/Ethernet. They are 100% plain UDP packets, they just happen to be sent via OS-bypass queues instead of traveling through the kernel networking stack.
>>
>> [^^^^^ there continues to be confusion about this for some reason, but I don't know why]
>
> So what is this patch for?

Does my earlier email clarify the situation any? http://marc.info/?l=linux-rdma&m=142972178630720&w=2

> commit 248567f79304b953ea492fb92ade097b62ed09b2
> Author: Upinder Malhi <umalhi-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org>
> Date: Thu Jan 9 14:48:19 2014 -0800
>
> IB/core: Add RDMA_TRANSPORT_USNIC_UDP
>
> Add RDMA_TRANSPORT_USNIC_UDP which will be used by usNIC.
>
> Signed-off-by: Upinder Malhi <umalhi-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org>
> Signed-off-by: Roland Dreier <roland-BHEL68pLQRGGvPXPguhicg@public.gmane.org>
>
> This is probably where a lot of the confusion is coming from.

Arguably RDMA_TRANSPORT_USNIC_UDP could/should have simply been named RDMA_TRANSPORT_UDP.

-Dave