Currently the iSCSI driver only solicits MaxXmitDSL(!) bytes with each R2T,
although it could solicit MaxBurstLength bytes.
This was introduced with the iSER driver and a RDMA_TRANSFER_SIZE constant to
limit the size of RDMA transfers. However, MaxBurstLength can and should be
used for that.
Signed-off-by: Arne Redlich <arne.redlich@xxxxxxxxxxxxxx>
---
Only lightly tested / untested (iSER), so review and test feedback very
much appreciated.
usr/iscsi/conn.c | 2 --
usr/iscsi/iscsi_rdma.c | 14 ++------------
usr/iscsi/iscsid.c | 27 +++++++++++++--------------
usr/iscsi/iscsid.h | 1 -
4 files changed, 15 insertions(+), 29 deletions(-)
diff --git a/usr/iscsi/conn.c b/usr/iscsi/conn.c
index 915f76f..56ba2c4 100644
--- a/usr/iscsi/conn.c
+++ b/usr/iscsi/conn.c
@@ -57,8 +57,6 @@ int conn_init(struct iscsi_connection *conn)
conn->refcount = 1;
conn->state = STATE_FREE;
param_set_defaults(conn->session_param, session_keys);
- conn->data_inout_max_length =
- conn->session_param[ISCSI_PARAM_MAX_XMIT_DLENGTH].val;
INIT_LIST_HEAD(&conn->clist);
INIT_LIST_HEAD(&conn->tx_clist);
diff --git a/usr/iscsi/iscsi_rdma.c b/usr/iscsi/iscsi_rdma.c
index 289b72d..b25abf7 100644
--- a/usr/iscsi/iscsi_rdma.c
+++ b/usr/iscsi/iscsi_rdma.c
@@ -241,7 +241,7 @@ static int waiting_rdma_slot;
* per connection, but many tasks might be in progress on the connection.
* Internal flow control stops tasks when there are no slots.
*
- * RDMA size tradeoffs:
+ * RDMA size tradeoffs (MaxBurstLength):
* big RDMA operations are more efficient
* small RDMA operations better for fairness with many clients
* small RDMA operations allow better pipelining
@@ -249,8 +249,6 @@ static int waiting_rdma_slot;
* entire buffer to transport in one go
*/
#define RDMA_PER_CONN 20
-#define RDMA_TRANSFER_SIZE (512 * 1024)
-
#define MAX_POLL_WC 8
@@ -1244,17 +1242,9 @@ static int iscsi_rdma_login_complete(struct iscsi_connection *conn)
ci->rsize = hdrsz + trdsl;
ci->max_outst_pdu = outst_pdu;
ret = iser_init_comm(ci);
- if (ret) {
+ if (ret)
eprintf("iser_init_comm failed\n");
- goto out;
- }
- /*
- * How much data to grab in an RDMA operation, read or write.
- */
- conn->data_inout_max_length = RDMA_TRANSFER_SIZE;
-
-out:
return ret;
}
diff --git a/usr/iscsi/iscsid.c b/usr/iscsi/iscsid.c
index 8e9876a..df7ce1f 100644
--- a/usr/iscsi/iscsid.c
+++ b/usr/iscsi/iscsid.c
@@ -528,13 +528,6 @@ static void login_finish(struct iscsi_connection *conn)
switch (conn->session_type) {
case SESSION_NORMAL:
/*
- * update based on negotiations (but ep_login_complete
- * could override)
- */
- conn->data_inout_max_length =
- conn->session_param[ISCSI_PARAM_MAX_XMIT_DLENGTH].val;
-
- /*
* Allocate transport resources for this connection.
*/
ret = conn->tp->ep_login_complete(conn);
@@ -977,7 +970,7 @@ static int iscsi_data_rsp_build(struct iscsi_task *task)
{
struct iscsi_connection *conn = task->conn;
struct iscsi_data_rsp *rsp = (struct iscsi_data_rsp *) &conn->rsp.bhs;
- int datalen;
+ int datalen, maxdatalen;
int result = scsi_get_result(&task->scmd);
memset(rsp, 0, sizeof(*rsp));
@@ -991,10 +984,15 @@ static int iscsi_data_rsp_build(struct iscsi_task *task)
datalen = min_t(uint32_t, scsi_get_in_length(&task->scmd), task->len);
datalen -= task->offset;
- dprintf("%d %d %d %d %x\n", datalen, scsi_get_in_length(&task->scmd),
- task->len, conn->data_inout_max_length, rsp->itt);
+ maxdatalen = conn->tp->rdma ?
+ conn->session_param[ISCSI_PARAM_MAX_BURST].val :
+ conn->session_param[ISCSI_PARAM_MAX_XMIT_DLENGTH].val;
+
+ dprintf("%d %d %d %" PRIu32 "%x\n", datalen,
+ scsi_get_in_length(&task->scmd), task->len, maxdatalen,
+ rsp->itt);
- if (datalen <= conn->data_inout_max_length) {
+ if (datalen <= maxdatalen) {
rsp->flags = ISCSI_FLAG_CMD_FINAL;
/* collapse status into final packet if successful */
@@ -1007,7 +1005,7 @@ static int iscsi_data_rsp_build(struct iscsi_task *task)
calc_residual((struct iscsi_cmd_rsp *) rsp, task);
}
} else
- datalen = conn->data_inout_max_length;
+ datalen = maxdatalen;
rsp->exp_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn);
rsp->max_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn + MAX_QUEUE_CMD);
@@ -1026,7 +1024,7 @@ static int iscsi_r2t_build(struct iscsi_task *task)
{
struct iscsi_connection *conn = task->conn;
struct iscsi_r2t_rsp *rsp = (struct iscsi_r2t_rsp *) &conn->rsp.bhs;
- int length;
+ uint32_t length;
memset(rsp, 0, sizeof(*rsp));
@@ -1040,7 +1038,8 @@ static int iscsi_r2t_build(struct iscsi_task *task)
/* return next statsn for this conn w/o advancing it */
rsp->statsn = cpu_to_be32(conn->stat_sn);
rsp->ttt = (unsigned long) task;
- length = min(task->r2t_count, conn->data_inout_max_length);
+ length = min_t(uint32_t, task->r2t_count,
+ conn->session_param[ISCSI_PARAM_MAX_BURST].val);
rsp->data_length = cpu_to_be32(length);
return 0;
diff --git a/usr/iscsi/iscsid.h b/usr/iscsi/iscsid.h
index 7897c41..b301c78 100644
--- a/usr/iscsi/iscsid.h
+++ b/usr/iscsi/iscsid.h
@@ -146,7 +146,6 @@ struct iscsi_connection {
int tid;
struct param session_param[ISCSI_PARAM_MAX];
- int data_inout_max_length;
char *initiator;
uint8_t isid[6];
--
1.6.0.4
--
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