Re: [2.6.20][PATCH] fix mempolicy error check on a system with memory-less-node

KAMEZAWA Hiroyuki
2007-02-07T10:38:03Z

On Wed, 7 Feb 2007 11:19:02 +0100
Andi Kleen <ak@suse.de> wrote:

>
> > AFAIK, ia64 creates nodes just depends on SRAT's possible resource information.
> > Then, ia64 can create cpu-memory-less-node(node with no available resource.).
> > (*)I don't like this.
> >
> > If we don't allow memory-less-node, we may have to add several codes for cpu-hot-add.
> > cpus should be moved to nearby node at hotadd .
> > And node-hot-add have to care that cpus mustn't be added before memory, cpu-driven
> > node-hot-add will never occur. (ACPI's 'container' device spec can't guaranntee this.)
>
> You can also alias node numbers to solve this: just point multiple node numbers
> to the same pgdat. For a memory less node this would be a nearby one.
>
Hmm, interesting...the 'alias' means follwing ?
==
NODE_DATA(A) = pgdat_for_A
NODE_DATA(B) = pgdat_for_A // B is memory-less.
- NODE_DATA(B) is valid but B is not online.
==
looks complicated..and we have to care /sys/devices/system/node handling.

-Kame