Commit 7bae25df authored by Jim Harris's avatar Jim Harris
Browse files

iscsi: remove flush timeout 



This concept was added very early in the SPDK iSCSI target
development process when there was a high focus on maximizing
throughput on a single iSCSI connection with 512-byte reads.

Realistically, in multi-connection environments focused on
predominantly 4KB (or more) workloads, this concept loses its
effectiveness - it is relatively rare that PDUs from multiple
I/O would coalesce within the default 8us flush timeout period.

There were no users of flush timeout in the SPDK tree - it was
not even documented in the iSCSI configuration file example and
there was no way to modify it at run time.  So leave the change
out of the CHANGELOG.

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: I08c3e959fb3945dc2c9cb89248305d0c88aa778f

Reviewed-on: https://review.gerrithub.io/395520


Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatar <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
parent 5f247660

lib/iscsi/conn.c

+3 −9
Original line number Diff line number Diff line
@@ -1372,7 +1372,6 @@ static int 
spdk_iscsi_conn_execute(struct spdk_iscsi_conn *conn)

{

	int				rc = 0;

	uint64_t			tsc;

	bool				conn_active = false;



	if (conn->state == ISCSI_CONN_STATE_EXITED) {
@@ -1399,15 +1398,10 @@ spdk_iscsi_conn_execute(struct spdk_iscsi_conn *conn) 
		conn_active = true;

	}



	/* If flush timer has expired, flush all PDUs */

	tsc = spdk_get_ticks();

	if (tsc - conn->last_flush > g_spdk_iscsi.flush_timeout) {

		conn->last_flush = tsc;

	if (spdk_iscsi_conn_flush_pdus(conn) != 0) {

		conn->state = ISCSI_CONN_STATE_EXITING;

		goto conn_exit;

	}

	}



	spdk_iscsi_conn_handle_queued_datain_tasks(conn);

lib/iscsi/iscsi.h

+0 −2
Original line number Diff line number Diff line
@@ -76,7 +76,6 @@ 
#define DEFAULT_TIMEOUT 60

#define MAX_NOPININTERVAL 60

#define DEFAULT_NOPININTERVAL 30

#define DEFAULT_FLUSH_TIMEOUT 8



/*

 * SPDK iSCSI target currently only supports 64KB as the maximum data segment length
@@ -271,7 +270,6 @@ struct spdk_iscsi_globals { 
	int req_discovery_auth;

	int req_discovery_auth_mutual;

	int discovery_auth_group;

	uint64_t flush_timeout;



	uint32_t MaxSessions;

	uint32_t MaxConnectionsPerSession;

lib/iscsi/iscsi_rpc.c

+0 −3
Original line number Diff line number Diff line
@@ -1104,9 +1104,6 @@ spdk_rpc_get_iscsi_global_params(struct spdk_jsonrpc_request *request, 
	spdk_json_write_name(w, "timeout");

	spdk_json_write_int32(w, g_spdk_iscsi.timeout);



	spdk_json_write_name(w, "flush_timeout");

	spdk_json_write_uint64(w, g_spdk_iscsi.flush_timeout);



	spdk_json_write_name(w, "nop_in_interval");

	spdk_json_write_int32(w, g_spdk_iscsi.nopininterval);

lib/iscsi/iscsi_subsystem.c

+0 −9
Original line number Diff line number Diff line
@@ -538,7 +538,6 @@ spdk_iscsi_log_globals(void) 
	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "ErrorRecoveryLevel %d\n",

		      g_spdk_iscsi.ErrorRecoveryLevel);

	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "Timeout %d\n", g_spdk_iscsi.timeout);

	SPDK_DEBUGLOG(SPDK_LOG_ISCSI, "FlushTimeout %"PRIu64"\n", g_spdk_iscsi.flush_timeout);

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

		      g_spdk_iscsi.nopininterval);

	if (g_spdk_iscsi.no_discovery_auth != 0) {
@@ -579,7 +578,6 @@ spdk_iscsi_read_parameters_from_config_file(struct spdk_conf_section *sp) 
	int nopininterval;

	int min_conn_per_core = 0;

	int conn_idle_interval = 0;

	int flush_timeout = 0;

	const char *ag_tag;

	int ag_tag_i;
@@ -685,10 +683,6 @@ spdk_iscsi_read_parameters_from_config_file(struct spdk_conf_section *sp) 
	if (timeout >= 0) {

		g_spdk_iscsi.timeout = timeout;

	}

	flush_timeout = spdk_conf_section_get_intval(sp, "FlushTimeout");

	if (flush_timeout >= 0) {

		g_spdk_iscsi.flush_timeout = flush_timeout;

	}

	nopininterval = spdk_conf_section_get_intval(sp, "NopInInterval");

	if (nopininterval >= 0) {

		if (nopininterval > MAX_NOPININTERVAL) {
@@ -761,7 +755,6 @@ spdk_iscsi_app_read_parameters(void) 
	g_spdk_iscsi.AllowDuplicateIsid = 0;

	g_spdk_iscsi.ErrorRecoveryLevel = DEFAULT_ERRORRECOVERYLEVEL;

	g_spdk_iscsi.timeout = DEFAULT_TIMEOUT;

	g_spdk_iscsi.flush_timeout = DEFAULT_FLUSH_TIMEOUT;

	g_spdk_iscsi.nopininterval = DEFAULT_NOPININTERVAL;

	g_spdk_iscsi.no_discovery_auth = 0;

	g_spdk_iscsi.req_discovery_auth = 0;
@@ -799,8 +792,6 @@ spdk_iscsi_app_read_parameters(void) 
	 */

	g_spdk_iscsi.MaxConnections = g_spdk_iscsi.MaxSessions;



	g_spdk_iscsi.flush_timeout *= (spdk_get_ticks_hz() >> 20);



	spdk_iscsi_log_globals();



	/* portal groups */