Re: [PATCH] percpu, x86: don't use PMD_SIZE as embedded atom_size on 32bit

H. Peter Anvin
2012-04-27T17:17:38Z

On 04/27/2012 09:53 AM, Tejun Heo wrote:
>
> + /*
> + * If PSE is available, use PMD_SIZE for atom_size so that
> + * embedded percpu areas are aligned to PMD. This, in the
> + * future, can also allow using PMD mappings in vmalloc
> + * area. Use PAGE_SIZE on 32bit as vmalloc space is highly
> + * contended and large vmalloc area alloc can easily fail.
> + */
> + atom_size = PAGE_SIZE;
> +#ifdef CONFIG_X86_64
> + if (cpu_has_pse)
> + atom_size = PMD_SIZE;
> +#endif

Just make it PAGE_SIZE on i386 and PMD_SIZE on x86-64; keep the behavior
consistent. !cpu_has_pse on x86-64 is an abnormal situation (I think it
applies to Xen, pretty much.)

Other than that,

Acked-by: H. Peter Anvin <hpa@zytor.com>

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.