Re: [Lse-tech] Re: idle task's task_t allocation on NUMA machines

Andi Kleen
2005-08-18T21:32:43Z

On Thu, Aug 18, 2005 at 10:02:55PM +0200, Samuel Thibault wrote:
> Samuel Thibault, le Thu 18 Aug 2005 21:49:41 +0200, a ?crit :
> > Eric Dumazet, le Thu 18 Aug 2005 17:18:55 +0200, a ?crit :
> > > I believe IRQ stacks are also allocated on node 0, that seems more serious.
> >
> > For the i386 architecture at least, yes: they are statically defined in
> > arch/i386/kernel/irq.c, while they could be per_cpu.
>
> Hum, but the per_cpu areas for i386 are not numa-aware... I'm wondering:
> isn't the current x86_64 numa-aware implementation of per_cpu generic
> enough for any architecture?

Actually it's broken for many x86-64 configurations now that use SRAT because
we assign the nodes to CPUs only after this code runs. I was considering
to remove it.

-Andi