udp: enable busy polling for all sockets
UDP busy polling is restricted to connected UDP sockets.
This is because sk_busy_loop() only takes care of one NAPI context.
There are cases where it could be extended.
1) Some hosts receive traffic on a single NIC, with one RX queue.
2) Some applications use SO_REUSEPORT and associated BPF filter
to split the incoming traffic on one UDP socket per RX
queue/thread/cpu
3) Some UDP sockets are used to send/receive traffic for one flow, but
they do not bother with connect()
This patch records the napi_id of first received skb, giving more
reach to busy polling.
Tested:
lpaa23:~# echo 70 >/proc/sys/net/core/busy_read
lpaa24:~# echo 70 >/proc/sys/net/core/busy_read
lpaa23:~# for f in `seq 1 10`; do ./super_netperf 1 -H lpaa24 -t UDP_RR -l 5; done
Before patch :
27867 28870 37324 41060 41215
36764 36838 44455 41282 43843
After patch :
73920 73213 70147 74845 71697
68315 68028 75219 70082 73707
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h
index 965e52b..d73b849 100644
--- a/include/net/busy_poll.h
+++ b/include/net/busy_poll.h
@@ -80,11 +80,6 @@ static inline void skb_mark_napi_id(struct sk_buff *skb,
skb->napi_id = napi->napi_id;
}
-/* used in the protocol hanlder to propagate the napi_id to the socket */
-static inline void sk_mark_napi_id(struct sock *sk, struct sk_buff *skb)
-{
- sk->sk_napi_id = skb->napi_id;
-}
#else /* CONFIG_NET_RX_BUSY_POLL */
static inline unsigned long net_busy_loop_on(void)
@@ -107,10 +102,6 @@ static inline void skb_mark_napi_id(struct sk_buff *skb,
{
}
-static inline void sk_mark_napi_id(struct sock *sk, struct sk_buff *skb)
-{
-}
-
static inline bool busy_loop_timeout(unsigned long end_time)
{
return true;
@@ -122,4 +113,23 @@ static inline bool sk_busy_loop(struct sock *sk, int nonblock)
}
#endif /* CONFIG_NET_RX_BUSY_POLL */
+
+/* used in the protocol hanlder to propagate the napi_id to the socket */
+static inline void sk_mark_napi_id(struct sock *sk, const struct sk_buff *skb)
+{
+#ifdef CONFIG_NET_RX_BUSY_POLL
+ sk->sk_napi_id = skb->napi_id;
+#endif
+}
+
+/* variant used for unconnected sockets */
+static inline void sk_mark_napi_id_once(struct sock *sk,
+ const struct sk_buff *skb)
+{
+#ifdef CONFIG_NET_RX_BUSY_POLL
+ if (!sk->sk_napi_id)
+ sk->sk_napi_id = skb->napi_id;
+#endif
+}
+
#endif /* _LINUX_NET_BUSY_POLL_H */
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 9ae7c63..e1fc011 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1569,6 +1569,8 @@ static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
sock_rps_save_rxhash(sk, skb);
sk_mark_napi_id(sk, skb);
sk_incoming_cpu_update(sk);
+ } else {
+ sk_mark_napi_id_once(sk, skb);
}
rc = __udp_enqueue_schedule_skb(sk, skb);
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 86a8cac..4f99417 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -519,6 +519,8 @@ static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
sock_rps_save_rxhash(sk, skb);
sk_mark_napi_id(sk, skb);
sk_incoming_cpu_update(sk);
+ } else {
+ sk_mark_napi_id_once(sk, skb);
}
rc = __udp_enqueue_schedule_skb(sk, skb);
