lkml.org 
[lkml]   [2017]   [Sep]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH net-next 3/4] net: dsa: change dsa_ptr for a dsa_master
Hi Vivien


> diff --git a/include/net/dsa.h b/include/net/dsa.h
> index f4a5afc4255b..d5b24cd10f79 100644
> --- a/include/net/dsa.h
> +++ b/include/net/dsa.h
> @@ -130,11 +130,6 @@ struct dsa_switch_tree {
> */
> struct dsa_platform_data *pd;
>
> - /* Copy of tag_ops->rcv for faster access in hot path */
> - struct sk_buff * (*rcv)(struct sk_buff *skb,
> - struct net_device *dev,
> - struct packet_type *pt);
> -
> /*
> * The switch port to which the CPU is attached.
> */


> diff --git a/net/dsa/tag_dsa.c b/net/dsa/tag_dsa.c
> index fbf9ca954773..7897bbd1a110 100644
> --- a/net/dsa/tag_dsa.c
> +++ b/net/dsa/tag_dsa.c
> @@ -67,7 +67,8 @@ static struct sk_buff *dsa_xmit(struct sk_buff *skb, struct net_device *dev)
> static struct sk_buff *dsa_rcv(struct sk_buff *skb, struct net_device *dev,
> struct packet_type *pt)
> {
> - struct dsa_switch_tree *dst = dev->dsa_ptr;
> + struct dsa_master *master = dev->dsa_ptr;
> + struct dsa_switch_tree *dst = master->port->ds->dst;

This is on the hot path. Every frame received comes through here. We
have gone from one dereference to 4 dereference. That is going to
impact performance.

How about keeping a copy of dst and ds in master?

Andrew

\
 
 \ /
  Last update: 2017-09-02 17:30    [W:0.066 / U:2.344 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site