DAEMON_RUNNING is only used by checkerloop to indicate that
path checkers are running. checkerloop switches back and forth
between DAEMON_IDLE and DAEMON_RUNNING in every iteration, i.e.
it performs two status changes per second on an idle system.
The repeated sd_notify() calls cause a lot of traffic on dbus as
systemd forwards these messages on the system bus. This can be
seen with systemd.log_level=debug. Better skip these notifications
that don't provide useful information to the user, who is very
unlikely to catch the daemon in "running" state anyway.
Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
---
multipathd/main.c | 24 ++++++++++++++++++++----
1 file changed, 20 insertions(+), 4 deletions(-)
diff --git a/multipathd/main.c b/multipathd/main.c
index 4be2c579..b5e2b00d 100644
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -161,15 +161,27 @@ sd_notify_status(void)
case DAEMON_CONFIGURE:
return "STATUS=configure";
case DAEMON_IDLE:
- return "STATUS=idle";
case DAEMON_RUNNING:
- return "STATUS=running";
+ return "STATUS=up";
case DAEMON_SHUTDOWN:
return "STATUS=shutdown";
}
return NULL;
}
+static void do_sd_notify(enum daemon_status old_state)
+{
+ /*
+ * Checkerloop switches back and forth between idle and running state.
+ * No need to tell systemd each time.
+ * These notifications cause a lot of overhead on dbus.
+ */
+ if ((running_state == DAEMON_IDLE || running_state == DAEMON_RUNNING) &&
+ (old_state == DAEMON_IDLE || old_state == DAEMON_RUNNING))
+ return;
+ sd_notify(0, sd_notify_status());
+}
+
static void config_cleanup(void *arg)
{
pthread_mutex_unlock(&config_lock);
@@ -179,10 +191,12 @@ void post_config_state(enum daemon_status state)
{
pthread_mutex_lock(&config_lock);
if (state != running_state) {
+ enum daemon_status old_state = running_state;
+
running_state = state;
pthread_cond_broadcast(&config_cond);
#ifdef USE_SYSTEMD
- sd_notify(0, sd_notify_status());
+ do_sd_notify(old_state);
#endif
}
pthread_mutex_unlock(&config_lock);
@@ -195,6 +209,8 @@ int set_config_state(enum daemon_status state)
pthread_cleanup_push(config_cleanup, NULL);
pthread_mutex_lock(&config_lock);
if (running_state != state) {
+ enum daemon_status old_state = running_state;
+
if (running_state != DAEMON_IDLE) {
struct timespec ts;
@@ -207,7 +223,7 @@ int set_config_state(enum daemon_status state)
running_state = state;
pthread_cond_broadcast(&config_cond);
#ifdef USE_SYSTEMD
- sd_notify(0, sd_notify_status());
+ do_sd_notify(old_state);
#endif
}
}
--
2.14.0
--
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