Re: [PATCH] x86: mm: accurate the comments for STEP_SIZE_SHIFT macro

Yinghai Lu
2013-03-18T18:53:58Z

On Mon, Mar 18, 2013 at 3:21 AM, Lin Feng <linfeng@cn.fujitsu.com> wrote:
> For x86 PUD_SHIFT is 30 and PMD_SHIFT is 21, so the consequence of
> (PUD_SHIFT-PMD_SHIFT)/2 is 4. Update the comments to the code.
>
> Cc: Yinghai Lu <yinghai@kernel.org>
> Signed-off-by: Lin Feng <linfeng@cn.fujitsu.com>
> ---
> arch/x86/mm/init.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
> index 59b7fc4..637a95b 100644
> --- a/arch/x86/mm/init.c
> +++ b/arch/x86/mm/init.c
> @@ -389,7 +389,7 @@ static unsigned long __init init_range_memory_mapping(
> return mapped_ram_size;
> }
>
> -/* (PUD_SHIFT-PMD_SHIFT)/2 */
> +/* (PUD_SHIFT-PMD_SHIFT)/2+1 */
> #define STEP_SIZE_SHIFT 5
> void __init init_mem_mapping(void)
> {

9/2=4.5, so it becomes 5.