[ofw] port RDS to OFW - request for input...

[Tzachi Dar]

> -----Original Message-----
> From: Sean Hefty [mailto:sean.hefty at intel.com] 
> Sent: Friday, July 24, 2009 12:55 AM
> To: Tzachi Dar; Smith, Stan; Richard Frank; ofw at lists.openfabrics.org
> Subject: RE: [ofw] port RDS to OFW - request for input...
> 
> >Does the notation: "remote IP -> local IP, remote GID" 
> means, I want to 
> >connect to the remote IP x.x.x.x what is it's gid and what 
> is the local 
> >interface?
> 
> Yes
> 
> >I guess that if it is we can add this functionality to 
> ipoib. The way 
> >to do it is simple:
> >Send an arp packet to all interfaces and wait for response.
> 
> This is basically how it is implemented on Linux, except I 
> think that the local IP is determined first by looking at the 
> neighbor routing tables.
> 
> >Is this better than relaying on a user mode service to get that 
> >information? Hard to tell.
> 
> I've never tried to get a kernel client to communicate with a 
> user mode service, so I'm not sure either.
> 
Communicating is possibale only in one way from user to kernel.
In other words what this means is the kernel driver goes up and waits
for the user to connect to it. When the user service goes up it sends a
request which is actually a question "do you need help". The driver
waits until it has some question to ask. It than completes the user
request. The user finds the answer and then sends the answer to the
kernel. It then sends another request. 
This is the principal. Not too complicated but ugly in a scene of a
kernel library trusting a user to supply answers.

See http://www.osronline.com/article.cfm?id=94 for the details.