From cb2d45da81c86d5191b19d0f67732a854bc0253c Mon Sep 17 00:00:00 2001
From: David Teigland <teigland@redhat.com>
Date: Fri, 12 Nov 2010 11:12:55 -0600
Subject: dlm: use TCP_NODELAY

Nagling doesn't help and can sometimes hurt dlm comms.

Signed-off-by: David Teigland <teigland@redhat.com>

diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index 1d4e644..2bedb0a 100644
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -926,6 +926,7 @@ static void tcp_connect_to_sock(struct connection *con)
 	struct sockaddr_storage saddr, src_addr;
 	int addr_len;
 	struct socket *sock = NULL;
+	int one = 1;
 
 	if (con->nodeid == 0) {
 		log_print("attempt to connect sock 0 foiled");
@@ -971,6 +972,11 @@ static void tcp_connect_to_sock(struct connection *con)
 	make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len);
 
 	log_print("connecting to %d", con->nodeid);
+
+	/* Turn off Nagle's algorithm */
+	kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one,
+			  sizeof(one));
+
 	result =
 		sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len,
 				   O_NONBLOCK);
@@ -1022,6 +1028,10 @@ static struct socket *tcp_create_listen_sock(struct connection *con,
 		goto create_out;
 	}
 
+	/* Turn off Nagle's algorithm */
+	kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one,
+			  sizeof(one));
+
 	result = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
 				   (char *)&one, sizeof(one));
 
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