[dat-discussions] [openib-general] [RFC] DAT 2.0immediatedataproposal

[Sean Hefty]

>I am not clear what you are proposing?
>A transport specific API?
>
>The current proposal provides on sending side:
>single post, and single completion in the error free case.
>This is commonality that simplify ULP.

App 1 - transport aware:

if (transport == IB)
	Do something
else
	Do something different

App 2 - transport independent:

if (immediate data flag set)
	if (DTO == 1)
		Do something
	else
		do something else
else
	do something different

All you've done is add flags in order to call the API "transport neutral".  The
result to the application is the same, except that the interface is more complex
than it needs to be, and causes confusion on the receiving side.  And on the
sending side, the application still needs to check the flag to see if immediate
data is supported.

A true transport neutral API wouldn't need flags that specify the actual
differences between the transports.

The requirement is to provide an API that supports RDMA writes with immediate
data.  A send that follows an RDMA write is not immediate data, and the API
should not be constructed around trying to make it so.

If you want to add a new requirement to the API to support posting multiple work
requests with a single call, that is a different requirement.

- Sean