From fe8e4649397915cf3b2ab0b695929a27e543967e Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Thu, 6 Mar 2014 14:40:18 +0100 Subject: [PATCH] tipc: avoid to unnecessary process switch under non-block mode When messages are received via tipc socket under non-block mode, schedule_timeout() is called in tipc_wait_for_rcvmsg(), that is, the process of receiving messages will be scheduled once although timeout value passed to schedule_timeout() is 0. The same issue exists in accept()/wait_for_accept(). To avoid this unnecessary process switch, we only call schedule_timeout() if the timeout value is non-zero. Signed-off-by: Ying Xue Reviewed-by: Erik Hugne Reviewed-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/socket.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/tipc/socket.c b/net/tipc/socket.c index a4cf274..0ed0eaa 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -997,7 +997,7 @@ static int tipc_wait_for_rcvmsg(struct socket *sock, long timeo) for (;;) { prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); - if (skb_queue_empty(&sk->sk_receive_queue)) { + if (timeo && skb_queue_empty(&sk->sk_receive_queue)) { if (sock->state == SS_DISCONNECTING) { err = -ENOTCONN; break; @@ -1623,7 +1623,7 @@ static int tipc_wait_for_accept(struct socket *sock, long timeo) for (;;) { prepare_to_wait_exclusive(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); - if (skb_queue_empty(&sk->sk_receive_queue)) { + if (timeo && skb_queue_empty(&sk->sk_receive_queue)) { release_sock(sk); timeo = schedule_timeout(timeo); lock_sock(sk); -- 2.7.4