Re: [PATCH 08/49] drm: replace bitmap_weight with bitmap_empty where appropriate

From: Dmitry Baryshkov
Date: Thu Feb 10 2022 - 21:12:05 EST


On Fri, 11 Feb 2022 at 02:09, Yury Norov <yury.norov@xxxxxxxxx> wrote:
>
> smp_request_block() in drivers/gpu/drm/msm/disp/mdp5/mdp5_smp.c calls
> bitmap_weight() to check if any bit of a given bitmap is set. It's
> better to use bitmap_empty() in that case because bitmap_empty() stops
> traversing the bitmap as soon as it finds first set bit, while
> bitmap_weight() counts all bits unconditionally.
>
> Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx>
> ---
> drivers/gpu/drm/msm/disp/mdp5/mdp5_smp.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_smp.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_smp.c
> index d7fa2c49e741..56a3063545ec 100644
> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_smp.c
> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_smp.c
> @@ -68,7 +68,7 @@ static int smp_request_block(struct mdp5_smp *smp,
> uint8_t reserved;
>
> /* we shouldn't be requesting blocks for an in-use client: */
> - WARN_ON(bitmap_weight(cs, cnt) > 0);
> + WARN_ON(!bitmap_empty(cs, cnt));

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>

>
> reserved = smp->reserved[cid];
>
> --
> 2.32.0
>


--
With best wishes
Dmitry