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tipc: eliminate redundant buffer cloning at transmission
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Since all packet transmitters (link, bcast, discovery) are now sending
consumable buffer clones to the bearer layer, we can remove the
redundant buffer cloning that is perfomed in the lower level functions
tipc_l2_send_msg() and tipc_udp_send_msg().

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Jon Paul Maloy authored and David S. Miller committed Oct 24, 2015
1 parent 60852d6 commit 7214bcf
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Showing 2 changed files with 15 additions and 28 deletions.
31 changes: 10 additions & 21 deletions net/tipc/bearer.c
Original file line number Diff line number Diff line change
Expand Up @@ -414,34 +414,29 @@ void tipc_disable_l2_media(struct tipc_bearer *b)
* @b_ptr: the bearer through which the packet is to be sent
* @dest: peer destination address
*/
int tipc_l2_send_msg(struct net *net, struct sk_buff *buf,
int tipc_l2_send_msg(struct net *net, struct sk_buff *skb,
struct tipc_bearer *b, struct tipc_media_addr *dest)
{
struct sk_buff *clone;
struct net_device *dev;
int delta;

dev = (struct net_device *)rcu_dereference_rtnl(b->media_ptr);
if (!dev)
return 0;

clone = skb_clone(buf, GFP_ATOMIC);
if (!clone)
return 0;

delta = dev->hard_header_len - skb_headroom(buf);
delta = dev->hard_header_len - skb_headroom(skb);
if ((delta > 0) &&
pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
kfree_skb(clone);
pskb_expand_head(skb, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
kfree_skb(skb);
return 0;
}

skb_reset_network_header(clone);
clone->dev = dev;
clone->protocol = htons(ETH_P_TIPC);
dev_hard_header(clone, dev, ETH_P_TIPC, dest->value,
dev->dev_addr, clone->len);
dev_queue_xmit(clone);
skb_reset_network_header(skb);
skb->dev = dev;
skb->protocol = htons(ETH_P_TIPC);
dev_hard_header(skb, dev, ETH_P_TIPC, dest->value,
dev->dev_addr, skb->len);
dev_queue_xmit(skb);
return 0;
}

Expand Down Expand Up @@ -491,8 +486,6 @@ void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id,
if (likely(b))
b->media->send_msg(net, skb, b, dest);
rcu_read_unlock();
/* Until we remove cloning in tipc_l2_send_msg(): */
kfree_skb(skb);
}

/* tipc_bearer_xmit() -send buffer to destination over bearer
Expand All @@ -514,8 +507,6 @@ void tipc_bearer_xmit(struct net *net, u32 bearer_id,
skb_queue_walk_safe(xmitq, skb, tmp) {
__skb_dequeue(xmitq);
b->media->send_msg(net, skb, b, dst);
/* Until we remove cloning in tipc_l2_send_msg(): */
kfree_skb(skb);
}
}
rcu_read_unlock();
Expand All @@ -541,8 +532,6 @@ void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id,
msg_set_mc_netid(hdr, net_id);
__skb_dequeue(xmitq);
b->media->send_msg(net, skb, b, &b->bcast_addr);
/* Until we remove cloning in tipc_l2_send_msg(): */
kfree_skb(skb);
}
}
rcu_read_unlock();
Expand Down
12 changes: 5 additions & 7 deletions net/tipc/udp_media.c
Original file line number Diff line number Diff line change
Expand Up @@ -155,14 +155,12 @@ static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
struct udp_bearer *ub;
struct udp_media_addr *dst = (struct udp_media_addr *)&dest->value;
struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
struct sk_buff *clone;
struct rtable *rt;

if (skb_headroom(skb) < UDP_MIN_HEADROOM)
pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC);

clone = skb_clone(skb, GFP_ATOMIC);
skb_set_inner_protocol(clone, htons(ETH_P_TIPC));
skb_set_inner_protocol(skb, htons(ETH_P_TIPC));
ub = rcu_dereference_rtnl(b->media_ptr);
if (!ub) {
err = -ENODEV;
Expand All @@ -172,7 +170,7 @@ static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
struct flowi4 fl = {
.daddr = dst->ipv4.s_addr,
.saddr = src->ipv4.s_addr,
.flowi4_mark = clone->mark,
.flowi4_mark = skb->mark,
.flowi4_proto = IPPROTO_UDP
};
rt = ip_route_output_key(net, &fl);
Expand All @@ -181,7 +179,7 @@ static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
goto tx_error;
}
ttl = ip4_dst_hoplimit(&rt->dst);
err = udp_tunnel_xmit_skb(rt, ub->ubsock->sk, clone,
err = udp_tunnel_xmit_skb(rt, ub->ubsock->sk, skb,
src->ipv4.s_addr,
dst->ipv4.s_addr, 0, ttl, 0,
src->udp_port, dst->udp_port,
Expand All @@ -204,7 +202,7 @@ static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
if (err)
goto tx_error;
ttl = ip6_dst_hoplimit(ndst);
err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, clone,
err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb,
ndst->dev, &src->ipv6,
&dst->ipv6, 0, ttl, src->udp_port,
dst->udp_port, false);
Expand All @@ -213,7 +211,7 @@ static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
return err;

tx_error:
kfree_skb(clone);
kfree_skb(skb);
return err;
}

Expand Down

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