[openib-general] How about ib_send_page() ?

[Hal Rosenstock]

Hi Vivek,

On Thu, 2005-05-19 at 12:41, Vivek Kashyap wrote:
> <snip...>
> 
> > 
> > The most interesting optimization available is implementing the IPoIB
> > connected mode draft, although I don't think it's as easy as Vivek
> > indicated -- for example, I'm not sure how to deal with having
> > different MTUs depending on the destination.
> 
> <snip...>
> 
> The draft does allow for a negotiation per connection for the implementations
> that wish to take advantage of it. However, an implementation can by default
> choose to use a 'connected-mode MTU' e.g. 32K always. It can then, for every 
> connection choose to, negotiate to this value and if it is not workable fall 
> back to the UD mode and deny the connection mode. The ARP entries hold the 
> connected mode flags thereby keeping track of the mode to use per destination. 

Sounds like there should be an "agreement" on a default connected mode
MTU or else this will drop down to UD.

I have a couple of clarification questions on 5.1 Per-Connection MTU:

1. I presume the Receive MTU is in the first 2 bytes of the private data
in the CM messages. Is that correct ?

2. Also, CM REQ is mentioned for the requester receive MTU. Wouldn't CM
REP carry the granted receive MTU which is constrained to be the
requested MTU or less ? So 2 things on this:
The I-D says "The private data field MUST carry" the receive MTU. Does
that include RTUs ?

Thanks.

-- Hal