lkml.org 
[lkml]   [2014]   [Feb]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] This extends tx_data and and iscsit_do_tx_data with the additional parameter flags and avoids sending multiple TCP packets in iscsit_fe_sendpage_sg
The new infrastructure is used in iscsit_fe_sendpage_sg to avoid sending three
TCP packets instead of one by settings the MSG_MORE when calling kernel_sendmsg
via the wrapper functions tx_data and iscsit_do_tx_data. This reduces the TCP
overhead by sending the same data in less TCP packets and minimized the TCP RTP
when TCP auto corking is enabled. When creating a 500 GB VMFS filesystem the
filesystem is created in 3 seconds instead of 4 seconds.

Signed-off-by: Thomas Glanzmann <thomas@glanzmann.de>
X-tested-by: Thomas Glanzmann <thomas@glanzmann.de>
---
drivers/target/iscsi/iscsi_target_parameters.c | 2 +-
drivers/target/iscsi/iscsi_target_util.c | 23 ++++++++++++-----------
drivers/target/iscsi/iscsi_target_util.h | 2 +-
3 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/drivers/target/iscsi/iscsi_target_parameters.c b/drivers/target/iscsi/iscsi_target_parameters.c
index 4d2e23f..b802392 100644
--- a/drivers/target/iscsi/iscsi_target_parameters.c
+++ b/drivers/target/iscsi/iscsi_target_parameters.c
@@ -79,7 +79,7 @@ int iscsi_login_tx_data(
*/
conn->if_marker += length;

- tx_sent = tx_data(conn, &iov[0], iov_cnt, length);
+ tx_sent = tx_data(conn, &iov[0], iov_cnt, length, 0);
if (tx_sent != length) {
pr_err("tx_data returned %d, expecting %d.\n",
tx_sent, length);
diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c
index e655b04..887fabb 100644
--- a/drivers/target/iscsi/iscsi_target_util.c
+++ b/drivers/target/iscsi/iscsi_target_util.c
@@ -1168,7 +1168,7 @@ send_data:
iov_count = cmd->iov_misc_count;
}

- tx_sent = tx_data(conn, &iov[0], iov_count, tx_size);
+ tx_sent = tx_data(conn, &iov[0], iov_count, tx_size, 0);
if (tx_size != tx_sent) {
if (tx_sent == -EAGAIN) {
pr_err("tx_data() returned -EAGAIN\n");
@@ -1199,7 +1199,8 @@ send_hdr:
iov.iov_base = cmd->pdu;
iov.iov_len = tx_hdr_size;

- tx_sent = tx_data(conn, &iov, 1, tx_hdr_size);
+ data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
+ tx_sent = tx_data(conn, &iov, 1, tx_hdr_size, data_len ? MSG_MORE : 0);
if (tx_hdr_size != tx_sent) {
if (tx_sent == -EAGAIN) {
pr_err("tx_data() returned -EAGAIN\n");
@@ -1208,7 +1209,6 @@ send_hdr:
return -1;
}

- data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
/*
* Set iov_off used by padding and data digest tx_data() calls below
* in order to determine proper offset into cmd->iov_data[]
@@ -1252,7 +1252,8 @@ send_padding:
if (cmd->padding) {
struct kvec *iov_p = &cmd->iov_data[iov_off++];

- tx_sent = tx_data(conn, iov_p, 1, cmd->padding);
+ tx_sent = tx_data(conn, iov_p, 1, cmd->padding,
+ conn->conn_ops->DataDigest ? MSG_MORE : 0);
if (cmd->padding != tx_sent) {
if (tx_sent == -EAGAIN) {
pr_err("tx_data() returned -EAGAIN\n");
@@ -1266,7 +1267,7 @@ send_datacrc:
if (conn->conn_ops->DataDigest) {
struct kvec *iov_d = &cmd->iov_data[iov_off];

- tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN);
+ tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN, 0);
if (ISCSI_CRC_LEN != tx_sent) {
if (tx_sent == -EAGAIN) {
pr_err("tx_data() returned -EAGAIN\n");
@@ -1352,11 +1353,12 @@ static int iscsit_do_rx_data(

static int iscsit_do_tx_data(
struct iscsi_conn *conn,
- struct iscsi_data_count *count)
+ struct iscsi_data_count *count,
+ int flags)
{
int data = count->data_length, total_tx = 0, tx_loop = 0, iov_len;
struct kvec *iov_p;
- struct msghdr msg;
+ struct msghdr msg = { .msg_flags = flags };

if (!conn || !conn->sock || !conn->conn_ops)
return -1;
@@ -1366,8 +1368,6 @@ static int iscsit_do_tx_data(
return -1;
}

- memset(&msg, 0, sizeof(struct msghdr));
-
iov_p = count->iov;
iov_len = count->iov_count;

@@ -1411,7 +1411,8 @@ int tx_data(
struct iscsi_conn *conn,
struct kvec *iov,
int iov_count,
- int data)
+ int data,
+ int flags)
{
struct iscsi_data_count c;

@@ -1424,7 +1425,7 @@ int tx_data(
c.data_length = data;
c.type = ISCSI_TX_DATA;

- return iscsit_do_tx_data(conn, &c);
+ return iscsit_do_tx_data(conn, &c, flags);
}

void iscsit_collect_login_stats(
diff --git a/drivers/target/iscsi/iscsi_target_util.h b/drivers/target/iscsi/iscsi_target_util.h
index 561a424..1b6b336 100644
--- a/drivers/target/iscsi/iscsi_target_util.h
+++ b/drivers/target/iscsi/iscsi_target_util.h
@@ -54,7 +54,7 @@ extern int iscsit_print_dev_to_proc(char *, char **, off_t, int);
extern int iscsit_print_sessions_to_proc(char *, char **, off_t, int);
extern int iscsit_print_tpg_to_proc(char *, char **, off_t, int);
extern int rx_data(struct iscsi_conn *, struct kvec *, int, int);
-extern int tx_data(struct iscsi_conn *, struct kvec *, int, int);
+extern int tx_data(struct iscsi_conn *, struct kvec *, int, int, int);
extern void iscsit_collect_login_stats(struct iscsi_conn *, u8, u8);
extern struct iscsi_tiqn *iscsit_snmp_get_tiqn(struct iscsi_conn *);

--
1.7.10.4


\
 
 \ /
  Last update: 2014-02-09 09:01    [W:0.115 / U:0.060 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site