Re: TOE brain dump

[Val Henson <val@nmt.edu>]

On Mon, Aug 04, 2003 at 11:30:27PM -0300, Werner Almesberger wrote:
> Larry McVoy wrote:
> > I'd suggest that all of you look at the fact that all of these offload 
> > card companies have ended up dieing.  I don't know of a single one that
> > made it to profitability.  Doesn't that tell you something?  What has 
> > changed that makes this a good idea?
> 
> 1) So far, most of the battle has been about data transfers.
>    Now, per-packet overhead is becoming an issue.
> 
> 2) AFAIK, they all went for designs that isolated their code
>    from the main stack. That's one thing that, IMHO, has to
>    change.
> 
> Is this enough to make TOE succeed ? I don't know.

Jeff Mogul recently wrote an interesting paper called "TCP Offload is
a Dumb Idea Whose Time Has Come":

http://www.usenix.org/events/hotos03/tech/full_papers/mogul/mogul_html/

(It's 6 pages long and in HTML - easy to read.)

After explaining why TCP offload is a dumb idea, he goes on to argue
that *if* storage area networks are replaced with switched ethernet,
and RDMA becomes popular, TCP offload might make sense for sending
data to your disks.

This is a good, short paper to read if you are interested in TOE for
any reason.

-VAL