Re: [discuss] Re: [patch 3/3] x86_64: Node local PDA -- allocate node local memory for pda

From: Ravikiran G Thirumalai
Date: Fri Dec 02 2005 - 13:23:54 EST


On Fri, Dec 02, 2005 at 09:54:59AM +0100, Eric Dumazet wrote:
> Ravikiran G Thirumalai a écrit :
> >Patch uses a static PDA array early at boot and reallocates processor PDA
> >with node local memory when kmalloc is ready, just before pda_init.
> >The boot_cpu_pda is needed sice the cpu_pda is used even before pda_init
> >for
> >that cpu is called (to set the static per-cpu areas offset table etc)
> >
>
> That sounds great.
>
> I have only have one suggestion : If kernel is not NUMA, then maybe we
> should avoid one indirection to get the pda, and avoid some code too.
>

Sure, but there is no extra indirection with the fastpath routines like
read_pda, write_pda and friends with the current patch.
Places where cpu_pda[] is accessed by the array name are not really
important -- except for the static per_cpu_offset of another cpu. But
still it might be worth it (considering that people use
per_cpu(var, smp_processor_id()), instead of __get_cpu_var in many places).
I will incorporate this.

Thanks,
Kiran
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/