Re: [PATCH] x86 NUMA panic compile error

Ingo Molnar
2006-05-15T18:49:40Z

* Andi Kleen <ak@suse.de> wrote:

> > So shouldn't such a patch remove that code rather than panicing?
>
> I would be for remove, but apparently we have one or two users in IBM
> that run their x440s (32bit only) with CONFIG_NUMA. No distributions
> do so though and I would expect x440s to usually run distributions
> because they are quite expensive machines.
>
> My arguments for remove:
> - The code is very hackish - it was written before the proper ACPI
> infrastructure is in place - and NUMA on 32bit in general needs a lot
> of hacks because of the limited ZONE_NORMAL.

works fine here now. The whole NUMA code is still quite hackish in
general, (including most of arch/x86_64/*/*.c), so i'd not judge based
on that.

> - NUMA on 32bit is kind of broken by design.

well. 32bit itself is broken by design, if you consider RAM larger than
say 1GB.

> - It isn't used much.

it's an enabler of a feature-set that i couldnt test on these boxes
otherwise. Look at it like the highmem= boot option. Or consider it a
primitive form of NUMA emulation.

> - It breaks often

Martin says he's daily testing it in his grid.

> - It tends to not work on Opterons and hits the users who try it
> there.

maybe due to the zone alignment problem?

Ingo