netdev - [PATCH v2 net-next 3/3] RDS-TCP: Set up MSG_MORE and MSG_SENDPAGE_NOTLAST as appropriate in rds_tcp

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 30 Sep 2015 16:54:09 -0400
From:	Sowmini Varadhan <sowmini.varadhan@...cle.com>
To:	netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:	davem@...emloft.net, rds-devel@....oracle.com,
	ajaykumar.hotchandani@...cle.com, igor.maximov@...cle.com,
	sowmini.varadhan@...cle.com, santosh.shilimkar@...cle.com,
	sergei.shtylyov@...entembedded.com
Subject: [PATCH v2 net-next 3/3] RDS-TCP: Set up MSG_MORE and MSG_SENDPAGE_NOTLAST as appropriate in rds_tcp_xmit

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@...cle.com>
---
v2: Sergei Shtylov, Santosh Shilimkar comments (some parens retained for
    readability)

 net/rds/tcp_send.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/net/rds/tcp_send.c b/net/rds/tcp_send.c
index 53b17ca..2894e60 100644
--- a/net/rds/tcp_send.c
+++ b/net/rds/tcp_send.c
@@ -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:
-- 
1.7.1

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html