Re: [patch[ Simple Topology API

["Martin J. Bligh" <Martin.Bligh@us.ibm.com>]

 
>> They can also go to no-glue 8-way:
>> 
>>     I/O -- A ------ B ------ E ------ G -- I/O
>>            |        |        |        | 
>>            |        |        |        | 
>>     I/O -- C ------ D ------ F ------ H -- I/O
> 
> 
> I think the 8-way topology is a little more interesting than
> presented.  But if not it does look like you can run into issues.
> The more I look at it there appears to be a strong dynamic balance
> in the architecture between having just enough bandwidth, and low
> enough latency not to become a bottleneck, and having a low hardware
> cost. 

Whilst I don't have a definitive diagram, the "back of a napkin" 
sketches we came up with at an OLS dinner looked like this:

     I/O -- A ------ B ---- E ------ G -- I/O
            |           \/           | 
            |           /\           | 
     I/O -- C ------ D ---- F ------ H -- I/O

(please excuse my poor artistic skills). That reduces the max
hops from 4 to 3 (if I haven't screwed something up).

M.