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: Thomas Glanzmann <hidden>
Date: 2014-02-08 21:36:14
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>
Hello Eric,
I was simply thinking about something like : (might need further changes, but I guess this should solve your case)
thank you for your patch. It did not apply on top of Linux tip, so I put in the changes manually and fixed up another call to tx_data that your forgot in your initial patch to make it apply. I gave it another run, can you confirm that it now behaves better? https://thomas.glanzmann.de/tmp/tcp_auto_corking_on_patched_tcp_more.pcap.bz2 And look at that roundtrip graph it is perfect. Also filesystem is now created in 3 seconds instead of 4. https://thomas.glanzmann.de/tmp/screenshot-mini-2014-02-08-22:34:57.png Nab, do you consider this patch for upstream? Would you take if I clean it up? Cheers, Thomas PS: I'm asleep for the next 8 hours.
diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c
index e655b04..0eb9681 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 +1353,13 @@ 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 +1369,6 @@ 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 +1412,8 @@ 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 +1426,7 @@ 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); }