Merge branch 'tcp-zero-copy-receive'

Eric Dumazet says:

====================
tcp: add zero copy receive

This patch series add mmap() support to TCP sockets for RX zero copy.

While tcp_mmap() patch itself is quite small (~100 LOC), optimal support
for asynchronous mmap() required better SO_RCVLOWAT behavior, and a
test program to demonstrate how mmap() on TCP sockets can be used.

Note that mmap() (and associated munmap()) calls are adding more
pressure on per-process VM semaphore, so might not show benefit
for processus with high number of threads.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/net.h b/include/linux/net.h
index 2248a052061d..6554d3ba4396 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -197,6 +197,7 @@ struct proto_ops {
 					   int offset, size_t size, int flags);
 	int		(*sendmsg_locked)(struct sock *sk, struct msghdr *msg,
 					  size_t size);
+	int		(*set_rcvlowat)(struct sock *sk, int val);
 };
 
 #define DECLARE_SOCKADDR(type, dst, src)	\
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 9c9b3768b350..833154e3df17 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -402,6 +402,10 @@ void tcp_set_keepalive(struct sock *sk, int val);
 void tcp_syn_ack_timeout(const struct request_sock *req);
 int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
 		int flags, int *addr_len);
+int tcp_set_rcvlowat(struct sock *sk, int val);
+void tcp_data_ready(struct sock *sk);
+int tcp_mmap(struct file *file, struct socket *sock,
+	     struct vm_area_struct *vma);
 void tcp_parse_options(const struct net *net, const struct sk_buff *skb,
 		       struct tcp_options_received *opt_rx,
 		       int estab, struct tcp_fastopen_cookie *foc);