[Rdma-developers] Re: [openib-general] OpenIB and OpenRDMA: Convergence on common RDMAAPIs and ULPs for Linux

[Bob Woodruff]

Catlin wrote,

>The sourceforge DAPL requires extensive parallel data between
>the DAPL layer and the verbs layer, that has a measurable impact
>on system performance. RNIC-PI not only avoids requiring either
>IB HCAs to pretend to be iWARP RNICs, or iWARP RNICs to pretend
>to be IB HCAs, it also provides features such as kernel mode
>completions and 'os_data' markers that eliminate the need for
>parallel DAPl/verbs data structures.

>Once this lowest-possible-RDMA-API is defined it will make it
>possible for *most* applications to work with only transport
>neutral fields and enums, and virtually all applications to
>do so for their non-error paths. But such an API is not a few
>minor tweaks away from the Gen2 verbs. Trying to sweep the
>differences under the rug in a "low level API" is what 
>produces truly ugly code.

The IB companies are not going to throw away a working implementation and
move to RNIC-PI, but people have already said that they are willing to work
with the iWarp 
community to add support and do what is right for Linux.

However, as Roland said earlier,

>Without seeing some real patches from the iWARP side, it's hard for me
>to see any value in continuing to participate in this debate.

> - R.

woody