RDS-TCP: Set up MSG_MORE and MSG_SENDPAGE_NOTLAST as appropriate in rds_tcp_xmit
authorSowmini Varadhan <sowmini.varadhan@oracle.com>
Wed, 30 Sep 2015 20:54:09 +0000 (16:54 -0400)
committerDavid S. Miller <davem@davemloft.net>
Mon, 5 Oct 2015 10:34:53 +0000 (03:34 -0700)
For the same reasons as commit 2f5338442425 ("tcp: allow splice() to
build full TSO packets") and commit 35f9c09fe9c7 ("tcp: tcp_sendpages()
should call tcp_push() once"), rds_tcp_xmit may have multiple pages to
send, so use the MSG_MORE and MSG_SENDPAGE_NOTLAST as hints to
tcp_sendpage()

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/rds/tcp_send.c

index 53b17ca0dff5a5618d92b2f6aeb876284707959b..2894e6095e3bbd841c082c1d983bf9f949090d16 100644 (file)
@@ -83,6 +83,7 @@ int rds_tcp_xmit(struct rds_connection *conn, struct rds_message *rm,
        struct rds_tcp_connection *tc = conn->c_transport_data;
        int done = 0;
        int ret = 0;
+       int more;
 
        if (hdr_off == 0) {
                /*
@@ -116,12 +117,15 @@ int rds_tcp_xmit(struct rds_connection *conn, struct rds_message *rm,
                        goto out;
        }
 
+       more = rm->data.op_nents > 1 ? (MSG_MORE | MSG_SENDPAGE_NOTLAST) : 0;
        while (sg < rm->data.op_nents) {
+               int flags = MSG_DONTWAIT | MSG_NOSIGNAL | more;
+
                ret = tc->t_sock->ops->sendpage(tc->t_sock,
                                                sg_page(&rm->data.op_sg[sg]),
                                                rm->data.op_sg[sg].offset + off,
                                                rm->data.op_sg[sg].length - off,
-                                               MSG_DONTWAIT|MSG_NOSIGNAL);
+                                               flags);
                rdsdebug("tcp sendpage %p:%u:%u ret %d\n", (void *)sg_page(&rm->data.op_sg[sg]),
                         rm->data.op_sg[sg].offset + off, rm->data.op_sg[sg].length - off,
                         ret);
@@ -134,6 +138,8 @@ int rds_tcp_xmit(struct rds_connection *conn, struct rds_message *rm,
                        off = 0;
                        sg++;
                }
+               if (sg == rm->data.op_nents - 1)
+                       more = 0;
        }
 
 out: