netdev - Re: [PATCH net-next 1/1] driver: macvlan: Remove duplicated IFF_UP condition check in macvlan_forward_source

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Date:   Sun, 20 Nov 2016 09:37:56 -0800
From:   Eric Dumazet <eric.dumazet@...il.com>
To:     fgao@...ai8.com
Cc:     davem@...emloft.net, kaber@...sh.net, netdev@...r.kernel.org,
        gfree.wind@...il.com
Subject: Re: [PATCH net-next 1/1] driver: macvlan: Remove duplicated IFF_UP
 condition check in macvlan_forward_source_one

On Sun, 2016-11-20 at 19:21 +0800, fgao@...ai8.com wrote:
> From: Gao Feng <gfree.wind@...il.com>
> 
> The condition check "dev->flags & IFF_UP" is duplicated in
> macvlan_forward_source_one, because its caller macvlan_forward_source
> has already checked this flag.
> 
> Signed-off-by: Gao Feng <gfree.wind@...il.com>
> ---
>  drivers/net/macvlan.c | 3 ---
>  1 file changed, 3 deletions(-)
> 
> diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
> index 13b7e0b..95a5ffc 100644
> --- a/drivers/net/macvlan.c
> +++ b/drivers/net/macvlan.c
> @@ -375,9 +375,6 @@ static void macvlan_forward_source_one(struct sk_buff *skb,
>  	int ret;
>  
>  	dev = vlan->dev;
> -	if (unlikely(!(dev->flags & IFF_UP)))
> -		return;
> -
>  	nskb = skb_clone(skb, GFP_ATOMIC);
>  	if (!nskb)
>  		return;

If you don't mind, I would rather remove the test in the caller and
leave it here. It is likely compiler inlines the function anyway, so
there is no performance change.