Re: r996 - in trunk/kernel/ia64/kernel-patch-2.6.7-ia64-2.6.7: .

Alex Williamson
2004-08-13T16:02:35Z

On Fri, 2004-08-13 at 08:29 -0700, Jesse Barnes wrote:
> On Friday, August 13, 2004 2:32 am, Christoph Hellwig wrote:
> > --- /dev/null Wed Dec 31 16:00:00 196900
> > +++ b/arch/ia64/kernel/numa.c 2004-08-12 18:28:06 -07:00
> > @@ -0,0 +1,46 @@
> > +#include <linux/config.h>
> > +#include <linux/topology.h>
> > +#include <linux/module.h>
> > +#include <asm/processor.h>
> > +#include <asm/smp.h>
> > +
> > +#ifdef CONFIG_NUMA
> >
> > You build this file conditional on CONFIG_
> > UMA, no need for this ifdef.
>
> Yep, you're right.
>

Ok, so you _can_ build NUMA in on a non-SMP kernel and you could even
imagine a single cpu box w/ multiple memory nodes. I think our code
base should be able to support such a system. However, for a distro
kernel, the purpose of a UP kernel is to ditch some of the high-end
overhead and tune it for a little box. What's the performance hit on a
box that doesn't need NUMA/DISCONTIG to turn these on for a UP kernel?
Maybe it's small enough I shouldn't be worried. Is there any way an
Altix could survive using the virtual memmap code on a UP build?

Alex

--
Alex Williamson HP Linux & Open Source Lab