Re: REGRESSION f54b311142a92ea2e42598e347b84e1655caf8e3 tcp auto corking slows down iSCSI file system creation by factor of 70 [WAS: 4 TB VMFS creation takes 15 minutes vs 26 seconds]
From: Eric Dumazet <hidden>
Date: 2014-02-08 19:12:47
Also in:
lkml
Subsystem:
scsi target subsystem, the rest · Maintainers:
"Martin K. Petersen", Linus Torvalds
Possibly related (same subject, not in this thread)
- 2014-02-08 · REGRESSION f54b311142a92ea2e42598e347b84e1655caf8e3 tcp auto corking slows down iSCSI file system creation by factor of 70 [WAS: 4 TB VMFS creation takes 15 minutes vs 26 seconds] · Thomas Glanzmann <hidden>
- 2014-02-08 · REGRESSION f54b311142a92ea2e42598e347b84e1655caf8e3 tcp auto corking slows down iSCSI file system creation by factor of 70 [WAS: 4 TB VMFS creation takes 15 minutes vs 26 seconds] · Thomas Glanzmann <hidden>
On Sat, 2014-02-08 at 18:15 +0100, Thomas Glanzmann wrote:
The iSCSI target uses one function to send all outbound data. So in order to do it right every function that is sending data in multiple chunks need to mark it correctly. Of course someone could also do some wild guessing and saying that everything that is below 512 Bytes gets pushed out. I wonder what Nab has to say about this?
I was simply thinking about something like : (might need further changes, but I guess this should solve your case)
diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c
index 0819e688a398..44f0d62a88d6 100644
--- a/drivers/target/iscsi/iscsi_target_util.c
+++ b/drivers/target/iscsi/iscsi_target_util.c@@ -1165,7 +1165,7 @@ 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");
@@ -1196,7 +1196,8 @@ 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");
@@ -1205,7 +1206,6 @@ 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[]
@@ -1249,7 +1249,8 @@ 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");
@@ -1263,7 +1264,7 @@ 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");
@@ -1349,11 +1350,12 @@ 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;
@@ -1363,8 +1365,6 @@ static int iscsit_do_tx_data( return -1; } - memset(&msg, 0, sizeof(struct msghdr)); - iov_p = count->iov; iov_len = count->iov_count;
@@ -1408,7 +1408,8 @@ int tx_data( struct iscsi_conn *conn, struct kvec *iov, int iov_count, - int data) + int data, + int flags) { struct iscsi_data_count c;
@@ -1421,7 +1422,7 @@ 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 e4fc34a02f57..1b4f06801adc 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 *);