net: SOCKWQ_ASYNC_WAITDATA optimizations

SOCKWQ_ASYNC_WAITDATA is set/cleared in sk_wait_data()
and equivalent functions, so that sock_wake_async() can send
a SIGIO only when necessary.

Since these atomic operations are really not needed unless
socket expressed interest in FASYNC, we can omit them in most
cases.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/sock.h b/include/net/sock.h
index 0f48aad..3df778c 100644 (file)
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1940,7 +1940,8 @@ static inline unsigned long sock_wspace(struct sock *sk)
  */
 static inline void sk_set_bit(int nr, struct sock *sk)
 {
-       if (nr == SOCKWQ_ASYNC_NOSPACE && !sock_flag(sk, SOCK_FASYNC))
+       if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
+           !sock_flag(sk, SOCK_FASYNC))
                return;
 
        set_bit(nr, &sk->sk_wq_raw->flags);
@@ -1948,7 +1949,8 @@ static inline void sk_set_bit(int nr, struct sock *sk)
 
 static inline void sk_clear_bit(int nr, struct sock *sk)
 {
-       if (nr == SOCKWQ_ASYNC_NOSPACE && !sock_flag(sk, SOCK_FASYNC))
+       if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
+           !sock_flag(sk, SOCK_FASYNC))
                return;
 
        clear_bit(nr, &sk->sk_wq_raw->flags);