Jack, this looks like a very nice machine indeed.  But I have a few questions as to the practical use of the memory banks.
 
1. Is each bank basically a memory slot or a set of slot pairs?
2. Is memory hot swappable?
3. Is cpumemsets used to map memory?
4. When do you anticipate that the processors of a node do not all have access (are allowed to access) all memory banks associated with that node?
5. Is I/O space (although interspersed between nodes) "local" to one of the nodes it sits between?
6. Is I/O space in effect just a fifth memory bank or how does it differ?
 
Thanks,
-nc- 

> ==============================================================================
> SGI SN2
>
> Each node consists of up to 4 discontiguous blocks of memory.
>
> This is the memory map for physical node 0.
> I've shown a typical way the node can be
> populated with memory.
>
> For other nodes, add 256GB*physical_node_num
> to each of the addresses.
>
> A few more oddities:
> - physical node numbers are all even numbers
> - physical nodes numbers are in the range of 0..2048
>   and can be very sparse.
> - IO space is interspersed BETWEEN the nodes - not
>   at the end.
> - physical node 0 normally doesnt exist. Starting
>   node number is indeterminate.
>
>
> (I hope the formatting doesnt get mangled.
>
>
>
> end     ------------------- 192GB+64GB
>         |  ///////////    |
>         |  ///////////    |
>         |    empty        |
>         |  ///////////    |
>         | - - - - - - - - |
>         |                 |
>         |      2GB        |
>         |-----------------| 192GB+48GB
>         |  ///////////    |
>         |  ///////////    |
>         |  ///////////    |
>         |    empty        |
>         |  ///////////    |
>         |  ///////////    |
>         |  ///////////    |
>         |-----------------| 192GB+32GB
>         |  ///////////    |
>         |    empty        |
>         |  ///////////    |
>         | - - - - - - - - |
>         |                 |
>         |      8GB        |
>         |                 |
>         |-----------------| 192GB+16GB
>         |  ///////////    |
>         |  ///////////    |
>         |    empty        |
>         |  ///////////    |
>         |  ///////////    |
>         | - - - - - - - - |
>         |      1GB        |
> start ------------------- 192GB
>
>
> A node consists of 4 chunks (banks or memblks) of memory. Chunks are populated
> independent of each other. Each chunk will have contiguous memory
> with no holes.
>
> The amount of memory in each chunk is 128MB, 256MB, 512MB ...
> 16GB. A few of the smaller sizes may be deprecated - I'll check.

> --
> Thanks
>
> Jack Steiner    (651-683-5302)   (vnet 233-5302)     
steiner@sgi.com