* [PATCH] af-packet: Use existing netdev reference for bound sockets.
@ 2011-05-25 23:15 greearb
2011-05-26 18:22 ` David Miller
0 siblings, 1 reply; 2+ messages in thread
From: greearb @ 2011-05-25 23:15 UTC (permalink / raw)
To: netdev; +Cc: Ben Greear
From: Ben Greear <greearb@candelatech.com>
This saves a network device lookup on each packet transmitted,
for sockets that are bound to a network device.
Signed-off-by: Ben Greear <greearb@candelatech.com>
---
:100644 100644 4005b24... 658edd1... M net/packet/af_packet.c
net/packet/af_packet.c | 26 +++++++++++++++++++-------
1 files changed, 19 insertions(+), 7 deletions(-)
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 4005b24..658edd1 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -987,8 +987,9 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
{
struct sk_buff *skb;
- struct net_device *dev;
+ struct net_device *dev = NULL;
__be16 proto;
+ bool need_rls_dev = false;
int ifindex, err, reserve = 0;
void *ph;
struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
@@ -1002,6 +1003,7 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
err = -EBUSY;
if (saddr == NULL) {
ifindex = po->ifindex;
+ dev = po->prot_hook.dev;
proto = po->num;
addr = NULL;
} else {
@@ -1017,7 +1019,10 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
addr = saddr->sll_addr;
}
- dev = dev_get_by_index(sock_net(&po->sk), ifindex);
+ if (!dev) {
+ dev = dev_get_by_index(sock_net(&po->sk), ifindex);
+ need_rls_dev = true;
+ }
err = -ENXIO;
if (unlikely(dev == NULL))
goto out;
@@ -1103,7 +1108,8 @@ out_status:
__packet_set_status(po, ph, status);
kfree_skb(skb);
out_put:
- dev_put(dev);
+ if (need_rls_dev)
+ dev_put(dev);
out:
mutex_unlock(&po->pg_vec_lock);
return err;
@@ -1139,8 +1145,9 @@ static int packet_snd(struct socket *sock,
struct sock *sk = sock->sk;
struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
struct sk_buff *skb;
- struct net_device *dev;
+ struct net_device *dev = NULL;
__be16 proto;
+ bool need_rls_dev = false;
unsigned char *addr;
int ifindex, err, reserve = 0;
struct virtio_net_hdr vnet_hdr = { 0 };
@@ -1161,6 +1168,7 @@ static int packet_snd(struct socket *sock,
if (saddr == NULL) {
ifindex = po->ifindex;
+ dev = po->prot_hook.dev;
proto = po->num;
addr = NULL;
} else {
@@ -1174,8 +1182,11 @@ static int packet_snd(struct socket *sock,
addr = saddr->sll_addr;
}
+ if (!dev) {
+ dev = dev_get_by_index(sock_net(sk), ifindex);
+ need_rls_dev = true;
+ }
- dev = dev_get_by_index(sock_net(sk), ifindex);
err = -ENXIO;
if (dev == NULL)
goto out_unlock;
@@ -1315,14 +1326,15 @@ static int packet_snd(struct socket *sock,
if (err > 0 && (err = net_xmit_errno(err)) != 0)
goto out_unlock;
- dev_put(dev);
+ if (need_rls_dev)
+ dev_put(dev);
return len;
out_free:
kfree_skb(skb);
out_unlock:
- if (dev)
+ if (dev && need_rls_dev)
dev_put(dev);
out:
return err;
--
1.7.3.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] af-packet: Use existing netdev reference for bound sockets.
2011-05-25 23:15 [PATCH] af-packet: Use existing netdev reference for bound sockets greearb
@ 2011-05-26 18:22 ` David Miller
0 siblings, 0 replies; 2+ messages in thread
From: David Miller @ 2011-05-26 18:22 UTC (permalink / raw)
To: greearb; +Cc: netdev
From: greearb@candelatech.com
Date: Wed, 25 May 2011 16:15:32 -0700
> @@ -1161,6 +1168,7 @@ static int packet_snd(struct socket *sock,
>
> if (saddr == NULL) {
> ifindex = po->ifindex;
> + dev = po->prot_hook.dev;
> proto = po->num;
> addr = NULL;
> } else {
> @@ -1174,8 +1182,11 @@ static int packet_snd(struct socket *sock,
> addr = saddr->sll_addr;
> }
>
> + if (!dev) {
> + dev = dev_get_by_index(sock_net(sk), ifindex);
> + need_rls_dev = true;
> + }
>
Why don't you move this second hunk into the "saddr != NULL" code
block?
That way all you can:
1) Call dev_get_by_index() unconditionally from that spot.
2) Only have the dev==NULL check right afterwards inside of the
unbound case as well.
^ permalink raw reply [flat|nested] 2+ messages in thread
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2011-05-26 18:22 ` David Miller
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