---

 libmultipath/config.c      |    1 +

 libmultipath/config.h      |    1 +

 libmultipath/dict.c        |   33 +++++++++++++++++++++++++++++++++

 libmultipath/discovery.c   |    8 ++++++--

 multipath.conf.annotated   |   10 ++++++++++

 multipath/multipath.conf.5 |    9 +++++++++

 6 files changed, 60 insertions(+), 2 deletions(-)

Index: multipath-tools-130222/libmultipath/config.c

===================================================================

--- multipath-tools-130222.orig/libmultipath/config.c

+++ multipath-tools-130222/libmultipath/config.c

@@ -556,6 +556,7 @@ load_config (char * file, struct udev *u

 	conf->retain_hwhandler = DEFAULT_RETAIN_HWHANDLER;

 	conf->detect_prio = DEFAULT_DETECT_PRIO;

 	conf->hw_strmatch = 0;

+	conf->force_sync = 0;

 	/*

 	 * preload default hwtable

Index: multipath-tools-130222/libmultipath/config.h

===================================================================

--- multipath-tools-130222.orig/libmultipath/config.h

+++ multipath-tools-130222/libmultipath/config.h

@@ -115,6 +115,7 @@ struct config {

 	int reassign_maps;

 	int retain_hwhandler;

 	int detect_prio;

+	int force_sync;

 	unsigned int version[3];

 	char * dev;

Index: multipath-tools-130222/libmultipath/dict.c

===================================================================

--- multipath-tools-130222.orig/libmultipath/dict.c

+++ multipath-tools-130222/libmultipath/dict.c

@@ -712,6 +712,29 @@ def_hw_strmatch_handler(vector strvec)

 	return 0;

 }

+static int

+def_force_sync_handler(vector strvec)

+{

+	char * buff;

+

+	buff = set_value(strvec);

+

+	if (!buff)

+		return 1;

+

+	if ((strlen(buff) == 2 && !strcmp(buff, "no")) ||

+	    (strlen(buff) == 1 && !strcmp(buff, "0")))

+		conf->force_sync = 0;

+	else if ((strlen(buff) == 3 && !strcmp(buff, "yes")) ||

+		 (strlen(buff) == 1 && !strcmp(buff, "1")))

+		conf->force_sync = 1;

+	else

+		conf->force_sync = 0;

+

+	FREE(buff);

+	return 0;

+}

+

 /*

  * blacklist block handlers

  */

@@ -2822,6 +2845,15 @@ snprint_def_hw_strmatch(char * buff, int

 }

 static int

+snprint_def_force_sync(char * buff, int len, void * data)

+{

+	if (conf->force_sync)

+		return snprintf(buff, len, "yes");

+	else

+		return snprintf(buff, len, "no");

+}

+

+static int

 snprint_ble_simple (char * buff, int len, void * data)

 {

 	struct blentry * ble = (struct blentry *)data;

@@ -2889,6 +2921,7 @@ init_keywords(void)

 	install_keyword("retain_attached_hw_handler", &def_retain_hwhandler_handler, &snprint_def_retain_hwhandler_handler);

 	install_keyword("detect_prio", &def_detect_prio_handler, &snprint_def_detect_prio);

 	install_keyword("hw_str_match", &def_hw_strmatch_handler, &snprint_def_hw_strmatch);

+	install_keyword("force_sync", &def_force_sync_handler, &snprint_def_force_sync);

 	__deprecated install_keyword("default_selector", &def_selector_handler, NULL);

 	__deprecated install_keyword("default_path_grouping_policy", &def_pgpolicy_handler, NULL);

 	__deprecated install_keyword("default_uid_attribute", &def_uid_attribute_handler, NULL);

Index: multipath-tools-130222/libmultipath/discovery.c

===================================================================

--- multipath-tools-130222.orig/libmultipath/discovery.c

+++ multipath-tools-130222/libmultipath/discovery.c

@@ -952,8 +952,12 @@ get_state (struct path * pp, int daemon)

 		}

 	}

 	checker_clear_message(c);

-	if (daemon)

-		checker_set_async(c);

+	if (daemon) {

+		if (conf->force_sync == 0)

+			checker_set_async(c);

+		else

+			checker_set_sync(c);

+	}

 	if (!conf->checker_timeout &&

 	    (pp->bus != SYSFS_BUS_SCSI ||

 	     sysfs_get_timeout(pp, &(c->timeout))))

Index: multipath-tools-130222/multipath.conf.annotated

===================================================================

--- multipath-tools-130222.orig/multipath.conf.annotated

+++ multipath-tools-130222/multipath.conf.annotated

@@ -214,6 +214,8 @@

 #	# values  : n > 0

 #	# default : determined by the OS

 #	dev_loss_tmo 600

+#

+#	#

 #	# name    : bindings_file

 #	# scope   : multipath

 #	# desc    : The location of the bindings file that is used with

@@ -222,6 +224,14 @@

 #	# default : "/var/lib/multipath/bindings"

 #	bindings_file "/etc/multipath_bindings"

 #

+#	#

+#	# name    : force_sync

+#	# scope   : multipathd

+#	# desc    : If set to yes, multipath will run all of the checkers in

+#	#           sync mode, even if the checker has an async mode.

+#	# values  : yes|no

+#	# default : no

+#	force_sync yes

 #}

 #	

 ##

Index: multipath-tools-130222/multipath/multipath.conf.5

===================================================================

--- multipath-tools-130222.orig/multipath/multipath.conf.5

+++ multipath-tools-130222/multipath/multipath.conf.5

@@ -411,6 +411,15 @@ modify an existing config, or create a n

 , the user device configs will be regular expression matched against the

 built-in configs instead. Default is

 .I no

+.TP

+.B force_sync

+If set to

+.I yes

+, multipathd will call the path checkers in sync mode only.  This means that

+only one checker will run at a time.  This is useful in the case where many

+multipathd checkers running in parallel causes significant CPU pressure. The

+Default is

+.I no

 .

 .SH "blacklist section"

 The