[PATCH v3 net-next 1/4] tcp: hint compiler about sack flows

[Eric Dumazet]

Tell the compiler that most TCP flows are using SACK these days.

There is no need to add the unlikely() clause in tcp_is_reno(),
the compiler is able to infer it.

Signed-off-by: Eric Dumazet <eduma...@google.com>
Acked-by: Neal Cardwell <ncardw...@google.com>
Acked-by: Yuchung Cheng <ych...@google.com>
---
 include/net/tcp.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 
63e37dd1c274cc396e41ea9612cf67a5b7c89776..0c61bf0a06dac95268c26b6302a2afbaef4c88b3
 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1124,7 +1124,7 @@ void tcp_rate_check_app_limited(struct sock *sk);
  */
 static inline int tcp_is_sack(const struct tcp_sock *tp)
 {
-       return tp->rx_opt.sack_ok;
+       return likely(tp->rx_opt.sack_ok);
 }
 
 static inline bool tcp_is_reno(const struct tcp_sock *tp)
-- 
2.20.0.rc0.387.gc7a69e6b6c-goog