Re: [PATCH v5 net-next 3/5] tcp: add TCP support for low latency receive poll.

Signed-off-by: Alexander Duyck <redacted>
Signed-off-by: Jesse Brandeburg <redacted>
Tested-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Eliezer Tamir <redacted>
---

 net/ipv4/tcp.c       |    5 +++++
 net/ipv4/tcp_input.c |    1 +
 net/ipv4/tcp_ipv4.c  |    2 ++
 3 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index d87ce72..652c75a 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c

@@ -279,6 +279,7 @@
 
 #include <asm/uaccess.h>
 #include <asm/ioctls.h>
+#include <net/ll_poll.h>
 
 int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
 

@@ -1551,6 +1552,10 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	struct sk_buff *skb;
 	u32 urg_hole = 0;
 
+	if (sk_valid_ll(sk) && skb_queue_empty(&sk->sk_receive_queue)
+	    && (sk->sk_state == TCP_ESTABLISHED))
+		sk_poll_ll(sk, nonblock);
+
 	lock_sock(sk);
 
 	err = -ENOTCONN;

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 9579e1a..4d82939 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c

@@ -74,6 +74,7 @@
 #include <linux/ipsec.h>
 #include <asm/unaligned.h>
 #include <net/netdma.h>
+#include <net/ll_poll.h>
 

 int sysctl_tcp_timestamps __read_mostly = 1;
 int sysctl_tcp_window_scaling __read_mostly = 1;

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index d20ede0..35fd8bc 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c

@@ -75,6 +75,7 @@
 #include <net/netdma.h>
 #include <net/secure_seq.h>
 #include <net/tcp_memcontrol.h>
+#include <net/ll_poll.h>
 
 #include <linux/inet.h>
 #include <linux/ipv6.h>

@@ -2011,6 +2012,7 @@ process:
 	if (sk_filter(sk, skb))
 		goto discard_and_relse;
 
+	sk_mark_ll(sk, skb);
 	skb->dev = NULL;
 
 	bh_lock_sock_nested(sk);