booting with `mem=' on an Altix (or other NUMA machine)

booting with `mem=' on an Altix (or other NUMA machine)

[Peter Chubb]

Looks like booting with mem=xxx doesn't work very well on a NUMA
machine ... one sees, `ernel panic - not syncing: pernode space for
node 1 could not be allocated!'

It is intended that the mem= command line work?  It would have to be
quite a bit more complex if so, to spread the memory across online nodes.
-- 
Dr Peter Chubb  http://www.gelato.unsw.edu.au  peterc AT gelato.unsw.edu.au
http://www.ertos.nicta.com.au           ERTOS within National ICT Australia

Re: booting with `mem=' on an Altix (or other NUMA machine)

[Grant Grundler]

On Tue, Apr 11, 2006 at 11:39:24AM +1000, Peter Chubb wrote:
> 
> Looks like booting with mem=xxx doesn't work very well on a NUMA
> machine ... one sees, `ernel panic - not syncing: pernode space for
> node 1 could not be allocated!'
> 
> It is intended that the mem= command line work?  It would have to be
> quite a bit more complex if so, to spread the memory across online nodes.

that was discussed before:
http://marc.theaimsgroup.com/?l=linux-ia64&m\x109718964113183&w=2

hth,
grant

Re: booting with `mem=' on an Altix (or other NUMA machine)

[Christoph Lameter]

On Mon, 10 Apr 2006, Grant Grundler wrote:

> that was discussed before:
> http://marc.theaimsgroup.com/?l=linux-ia64&m\x109718964113183&w=2

I only see a patch there but no discussion.

RE: booting with `mem=' on an Altix (or other NUMA machine)

[Luck, Tony]

>> that was discussed before:
>> http://marc.theaimsgroup.com/?l=linux-ia64&m\x109718964113183&w=2
>
>I only see a patch there but no discussion.

It doesn't look like this would solve the NUMA issue.  Maybe you'd
want a "mempernode=" boot parameter?  But this would likely get complex
in a hurry as various people add more options to meet their specific
needs.

-Tony

RE: booting with `mem=' on an Altix (or other NUMA machine)

[Chen, Kenneth W]

Luck, Tony wrote on Tuesday, April 11, 2006 10:32 AM
> >> that was discussed before:
> >> http://marc.theaimsgroup.com/?l=linux-ia64&m\x109718964113183&w=2
> >
> >I only see a patch there but no discussion.
> 
> It doesn't look like this would solve the NUMA issue.  Maybe you'd
> want a "mempernode=" boot parameter?  But this would likely get complex
> in a hurry as various people add more options to meet their specific
> needs.

We probably should disable that boot option on numa system and rely on
memory hotplug to reduce physical memory per node?

- Ken