Commit 5af42000 authored by Shuhei Matsumoto's avatar Shuhei Matsumoto Committed by Tomasz Zawadzki
Browse files

lib/iscsi: Make max outstanding R2Ts per connection configurable 



By the recent refactoring, we have no static size array for outstanding
R2Ts per connection. It looks that we do not have any critical reason
to prohibit us from making max outstanding R2Ts per connection configurable.

There are some use cases to use large write I/O intensively (e.g. 128KB).
Let such use cases change the value of max R2Ts per connection by their
responsibility to do performance tuning.

Maximum outstanding R2Ts per task are defined both for iSCSI target
and NVMe-TCP target but maximum outstanding R2Ts per connection is
unique for iSCSI target.

The next patch will add the corresponding iSCSI option.

Signed-off-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Change-Id: I4f6fd3c750a9a0a99bcf23064fe43a3389829aa9
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/3776


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
parent fb229e1e

lib/iscsi/iscsi.c

+2 −2
Original line number Diff line number Diff line
@@ -2735,7 +2735,7 @@ add_transfer_task(struct spdk_iscsi_conn *conn, struct spdk_iscsi_task *task) 
	 *  and start sending R2T for it after some of the tasks using R2T/data

	 *  out buffers complete.

	 */

	if (conn->pending_r2t >= DEFAULT_MAXR2T) {

	if (conn->pending_r2t >= g_iscsi.MaxR2TPerConnection) {

		TAILQ_INSERT_TAIL(&conn->queued_r2t_tasks, task, link);

		return 0;

	}
@@ -2785,7 +2785,7 @@ start_queued_transfer_tasks(struct spdk_iscsi_conn *conn) 
	struct spdk_iscsi_task *task, *tmp;



	TAILQ_FOREACH_SAFE(task, &conn->queued_r2t_tasks, link, tmp) {

		if (conn->pending_r2t < DEFAULT_MAXR2T) {

		if (conn->pending_r2t < g_iscsi.MaxR2TPerConnection) {

			TAILQ_REMOVE(&conn->queued_r2t_tasks, task, link);

			add_transfer_task(conn, task);

		} else {

lib/iscsi/iscsi.h

+1 −0
Original line number Diff line number Diff line
@@ -353,6 +353,7 @@ struct spdk_iscsi_globals { 
	uint32_t ErrorRecoveryLevel;

	bool AllowDuplicateIsid;

	uint32_t MaxLargeDataInPerConnection;

	uint32_t MaxR2TPerConnection;



	struct spdk_mempool *pdu_pool;

	struct spdk_mempool *pdu_immediate_data_pool;

lib/iscsi/iscsi_subsystem.c

+5 −1
Original line number Diff line number Diff line
@@ -141,7 +141,7 @@ mobj_ctor(struct spdk_mempool *mp, __attribute__((unused)) void *arg, 


#define NUM_PDU_PER_CONNECTION(iscsi)	(2 * (iscsi->MaxQueueDepth +	\

					 iscsi->MaxLargeDataInPerConnection +	\

					 2 * DEFAULT_MAXR2T + 8))

					 2 * iscsi->MaxR2TPerConnection + 8))

#define PDU_POOL_SIZE(iscsi)		(iscsi->MaxConnections * NUM_PDU_PER_CONNECTION(iscsi))

#define IMMEDIATE_DATA_POOL_SIZE(iscsi)	(iscsi->MaxConnections * 128)

#define DATA_OUT_POOL_SIZE(iscsi)	(iscsi->MaxConnections * MAX_DATA_OUT_PER_CONNECTION)
@@ -381,6 +381,9 @@ iscsi_log_globals(void) 


	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "MaxLargeDataInPerConnection %d\n",

		      g_iscsi.MaxLargeDataInPerConnection);



	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "MaxR2TPerConnection %d\n",

		      g_iscsi.MaxR2TPerConnection);

}



static void
@@ -780,6 +783,7 @@ iscsi_set_global_params(struct spdk_iscsi_opts *opts) 
	g_iscsi.mutual_chap = opts->mutual_chap;

	g_iscsi.chap_group = opts->chap_group;

	g_iscsi.MaxLargeDataInPerConnection = opts->MaxLargeDataInPerConnection;

	g_iscsi.MaxR2TPerConnection = DEFAULT_MAXR2T;



	iscsi_log_globals();

test/unit/lib/iscsi/iscsi.c/iscsi_ut.c

+4 −0
Original line number Diff line number Diff line
@@ -280,6 +280,8 @@ maxburstlength_test(void) 
	struct spdk_iscsi_pdu *response_pdu;

	int rc;



	g_iscsi.MaxR2TPerConnection = DEFAULT_MAXR2T;



	req_pdu = iscsi_get_pdu(&conn);

	data_out_pdu = iscsi_get_pdu(&conn);
@@ -654,6 +656,8 @@ add_transfer_task_test(void) 
	int rc, count = 0;

	uint32_t buffer_offset, desired_xfer_len;



	g_iscsi.MaxR2TPerConnection = DEFAULT_MAXR2T;



	sess.MaxBurstLength = SPDK_ISCSI_MAX_BURST_LENGTH;	/* 1M */

	sess.MaxOutstandingR2T = DEFAULT_MAXR2T;	/* 4 */