Subject: Re: [PATCH net-next 2/6] bonding: remove the no effect lock for bond_3ad_lacpdu_recv()

From: Rick Jones <[email-masked]>
Date: Fri, 30 Aug 2013 10:07:38 -0700

On 08/30/2013 03:04 AM, Ding Tianhong wrote:
> There is no pointer needed read lock protection, remove the unnecessary lock
> and improve performance for the 3ad recv path.

Improve performance by how much?  For example, by how much is service 
demand lower on a netperf TCP_STREAM or TCP_RR test through a bond.  I 
suppose that applies not only to this specific patch to to the set as a 
whole.

rick jones

>
> Signed-off-by: Ding Tianhong <[email-masked]>
> Cc: Nikolay Aleksandrov <[email-masked]>
> ---
>   drivers/net/bonding/bond_3ad.c | 2 --
>   1 file changed, 2 deletions(-)
>
> diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c
> index 7a3860f..c134f43 100644
> --- a/drivers/net/bonding/bond_3ad.c
> +++ b/drivers/net/bonding/bond_3ad.c
> @@ -2494,9 +2494,7 @@ int bond_3ad_lacpdu_recv(const struct sk_buff *skb, struct bonding *bond,
>   	if (!lacpdu)
>   		return ret;
>
> -	read_lock(&bond->lock);
>   	ret = bond_3ad_rx_indication(lacpdu, slave, skb->len);
> -	read_unlock(&bond->lock);
>   	return ret;
>   }
>
>