synchronize_net is called every time we close a PF_PACKET socket which is
causing performance loss when doing this on many sockets.
Signed-off-by: Sorin Dumitru <sdumi...@ixiacom.com>
Signed-off-by: Iulius Curt <ic...@ixiacom.com>
---
Statistics using test program [1]
Sockets count | Not patched | Patched
_________________________________________
1 000 000 | 1.28 s | 1.22 s
5 000 000 | 7.3 s | 6.25 s
50 000 000 | 72.89 s | 64.41 s
[1] http://pastebin.com/xQ9BziaP
---
net/packet/af_packet.c | 46 ++++++++++++++++++++++++++++++++++++----------
net/packet/internal.h | 1 +
2 files changed, 37 insertions(+), 10 deletions(-)
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 5dafe84..7b60135 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2299,6 +2299,32 @@ static int packet_sendmsg(struct kiocb *iocb, struct
socket *sock,
return packet_snd(sock, msg, len);
}
+void packet_release_finish(struct sock *sk, int null)
+{
+ struct socket *sock = sk->sk_socket;
+
+ sock_orphan(sk);
+ /* Modifing this after the socket has been released
+ * might lead to memory corruption so we don't do it */
+ if (null)
+ sock->sk = NULL;
+
+ /* Purge queues */
+
+ skb_queue_purge(&sk->sk_receive_queue);
+ sk_refcnt_debug_release(sk);
+
+ sock_put(sk);
+}
+
+void packet_release_rcu(struct rcu_head *rcu)
+{
+ struct packet_sock *po = container_of(rcu, struct packet_sock,
rcu_head);
+ struct sock *sk = &po->sk;
+
+ packet_release_finish(sk, 0);
+}
+
/*
* Close a PACKET socket. This is fairly simple. We immediately go
* to 'closed' state and remove our protocol entry in the device list.
@@ -2310,6 +2336,7 @@ static int packet_release(struct socket *sock)
struct packet_sock *po;
struct net *net;
union tpacket_req_u req_u;
+ int postpone = 0;
if (!sk)
return 0;
@@ -2326,7 +2353,10 @@ static int packet_release(struct socket *sock)
preempt_enable();
spin_lock(&po->bind_lock);
- unregister_prot_hook(sk, false);
+ if (po->running) {
+ postpone = 1;
+ __unregister_prot_hook(sk, false);
+ }
if (po->prot_hook.dev) {
dev_put(po->prot_hook.dev);
po->prot_hook.dev = NULL;
@@ -2345,19 +2375,15 @@ static int packet_release(struct socket *sock)
fanout_release(sk);
- synchronize_net();
/*
* Now the socket is dead. No more input will appear.
*/
- sock_orphan(sk);
- sock->sk = NULL;
-
- /* Purge queues */
-
- skb_queue_purge(&sk->sk_receive_queue);
- sk_refcnt_debug_release(sk);
+ if (postpone) {
+ call_rcu(&po->rcu_head, packet_release_rcu);
+ return 0;
+ }
- sock_put(sk);
+ packet_release_finish(sk, 1);
return 0;
}
diff --git a/net/packet/internal.h b/net/packet/internal.h
index 44945f6..5778c12 100644
--- a/net/packet/internal.h
+++ b/net/packet/internal.h
@@ -104,6 +104,7 @@ struct packet_sock {
int ifindex; /* bound device */
__be16 num;
struct packet_mclist *mclist;
+ struct rcu_head rcu_head;
atomic_t mapped;
enum tpacket_versions tp_version;
unsigned int tp_hdrlen;
--
1.7.9.5
--
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