From: Eric Dumazet <edumazet@google.com>
Date: Mon, 25 Apr 2016 17:39:34 +0000 (-0700)
Subject: net: SOCKWQ_ASYNC_WAITDATA optimizations
X-Git-Tag: v4.7-rc1~154^2~180^2
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=4be735225f7cd040ca81c18740e7b672021bafeb;p=linux.git

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 0f48aad9f8e8..3df778ccaa82 100644
--- 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);