1 files changed, 9 insertions, 6 deletions

diff --git a/include/net/sock.h b/include/net/sock.h
index 21db792bffa5..ea6206ccc896 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2047,18 +2047,21 @@ static inline void sk_wake_async(struct sock *sk, int how, int band)
                 sock_wake_async(sk->sk_socket, how, band);
 }
 
-#define SOCK_MIN_SNDBUF 2048
-/*
- * Since sk_rmem_alloc sums skb->truesize, even a small frame might need
- * sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak
+/* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
+ * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
+ * Note: for send buffers, TCP works better if we can build two skbs at
+ * minimum.
  */
-#define SOCK_MIN_RCVBUF (2048 + sizeof(struct sk_buff))
+#define TCP_SKB_MIN_TRUESIZE    (2048 + sizeof(struct sk_buff))
+
+#define SOCK_MIN_SNDBUF         (TCP_SKB_MIN_TRUESIZE * 2)
+#define SOCK_MIN_RCVBUF          TCP_SKB_MIN_TRUESIZE
 
 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
 {
         if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) {
                 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
-                sk->sk_sndbuf = max(sk->sk_sndbuf, SOCK_MIN_SNDBUF);
+                sk->sk_sndbuf = max_t(u32, sk->sk_sndbuf, SOCK_MIN_SNDBUF);
         }
 }