Re: [RFC][PATCH 1/2] export NUMA topology from xen

[Keir Fraser <keir@xensource.com>]

On 10/4/07 02:09, "Ryan Harper" <ryanh@us.ibm.com> wrote:

> nr_nodes               : 4
> mem_chunks             : node0:0x0000000000000000-0x0000000190000000
>                          node1:0x0000000190000000-0x0000000300000000
>                          node2:0x0000000300000000-0x0000000470000000
>                          node3:0x0000000470000000-0x0000000640000000
> node_to_cpu            : node0:0-7
>                          node1:8-15
>                          node2:16-23
>                          node3:24-31
> 
> I've also reworked the the physinfo call to contain an array of
> cpu_to_node elements rather than node_to_cpu to support machines larger
> than 64-way.  I convert the array back to node_to_cpu for brevity in
> xm info display.

The same would make sense for memory regions (i.e., have a list of
memory-regions and include a node identifier for each one, rather than
mapping node-id to memory-region) as this would allow to have multiple
memory regions per node quite easily. But actually I'm not convinced that
allowing dom0 to read out the physical addresses of memory regions is at all
useful -- why would anyone care which particular physical address ranges
belong to a particular node? The hypercall to find amount of free memory per
node seems more useful, and probably sufficient by itself.

 -- Keir