Re: [PATCH] net-sysfs: Slightly optimize 'xps_queue_show()'

From: Xin Long
Date: Mon Nov 22 2021 - 10:23:21 EST


On Sun, Nov 21, 2021 at 2:38 PM Christophe JAILLET
<christophe.jaillet@xxxxxxxxxx> wrote:
>
> The 'mask' bitmap is local to this function. So the non-atomic
> '__set_bit()' can be used to save a few cycles.
>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> ---
> net/core/net-sysfs.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
> index 9c01c642cf9e..3be3f4a6add3 100644
> --- a/net/core/net-sysfs.c
> +++ b/net/core/net-sysfs.c
> @@ -1452,7 +1452,7 @@ static ssize_t xps_queue_show(struct net_device *dev, unsigned int index,
>
> for (i = map->len; i--;) {
> if (map->queues[i] == index) {
> - set_bit(j, mask);
> + __set_bit(j, mask);
> break;
> }
> }
> --
> 2.30.2
>
The similar optimization can seem to be done in br_vlan.c and br_if.c as well.