diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index f8cf090e8f49..9ff456e8d6c7 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -343,7 +343,8 @@ struct tcp_sock {
 	struct sk_buff *forward_skb_hint;
 	struct sk_buff *fastpath_skb_hint;
 
-	int     fastpath_cnt_hint;
+	int     fastpath_cnt_hint;	/* Lags behind by current skb's pcount
+					 * compared to respective fackets_out */
 	int     lost_cnt_hint;
 	int     retransmit_cnt_hint;