Re: [PATCH] mm: percpu: micro-optimize round-to-even

[Tejun Heo]

On Thu, Jun 19, 2014 at 12:02:29PM +0200, Rasmus Villemoes wrote:
> This change shaves a few bytes off the generated code.
> 
> Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
> ---
>  mm/percpu.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/mm/percpu.c b/mm/percpu.c
> index 2ddf9a9..978097f 100644
> --- a/mm/percpu.c
> +++ b/mm/percpu.c
> @@ -720,8 +720,7 @@ static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved)
>  	if (unlikely(align < 2))
>  		align = 2;
>  
> -	if (unlikely(size & 1))
> -		size++;
> +	size += size & 1;

I'm not gonna apply this.  This isn't that hot a path.  It's not
worthwhile to micro optimize code like this.

Thanks.

-- 
tejun
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