Re: [Lhns-devel] Re: Who's doing what with cpu/memory/node hotplug?

Yasunori Goto
2004-05-14T00:13:15Z

Hello.

> > Iam not sure what specifically you are looking for ...
>
> I was looking for the short and sweet overview such as you just
> presented ;). Thanks.
>
> I need to start following this hotplug work because it is next door to
> the cpu/memory placement work that I am most focused on, such as
> cpusets, led by Simon Derr of Bull, sitting on top of sched_setaffinity
> and Andi Kleen's numa work. A cpuset is a set of cpu and memory
> resources that several tasks share, perhaps exclusively (all other
> tasks kept out).
>
> At some point, questions such as "what happens when a node is unplugged
> from a cpuset" will need to be answered. And even earlier, "what happens
> when a cpu is unplugged that was in a tasks cpus_allowed, or a memory
> node unplugged, that was in a vma's list of allowed memory zones."
>
> Or perhaps the answers to these questions are already known ??

At least, there aren't enough answer about memory hotplug yet
if there is a process that is using memory affinity.

But did you see Iwamoto-san's patch ?
This is infrastructure that contents of memory can
migrate from a node to other node.
If remap_onepage() of his patch execute on same cpus of that process
or 'node id' is specified, it will migrate to appriciate node.
I think it can be your help.

But, probably you might think many other works are necessary, right?

Thanks.

--
Yasunori Goto <ygoto at us.fujitsu.com>