Re: [PATCH 3/3] vhost-net: use lock_sock_fast() in peek_head_len()

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Jan 17, 2011 at 04:11:17PM +0800, Jason Wang wrote:
> We can use lock_sock_fast() instead of lock_sock() in order to get
> speedup in peek_head_len().
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>

Queued for 2.6.39, thanks everyone.

> ---
>  drivers/vhost/net.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> index c32a2e4..50b622a 100644
> --- a/drivers/vhost/net.c
> +++ b/drivers/vhost/net.c
> @@ -211,12 +211,12 @@ static int peek_head_len(struct sock *sk)
>  {
>  	struct sk_buff *head;
>  	int len = 0;
> +	bool slow = lock_sock_fast(sk);
>  
> -	lock_sock(sk);
>  	head = skb_peek(&sk->sk_receive_queue);
>  	if (head)
>  		len = head->len;
> -	release_sock(sk);
> +	unlock_sock_fast(sk, slow);
>  	return len;
>  }
>