X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=kernel%2Fwatchdog.c;h=1f1b05f5a94b8edaf014495a985168b39d73877f;hb=9aa987e46128bc063765af2a720561256cd69e32;hp=e864906af3fc7a733831542c52547acf7a4821d7;hpb=49f63e15598e09f24e0528e7cad18d6dec2ba804;p=firefly-linux-kernel-4.4.55.git

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index e864906af3fc..1f1b05f5a94b 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -1020,6 +1020,9 @@ static int proc_watchdog_common(int which, struct ctl_table *table, int write,
 		 * both lockup detectors are disabled if proc_watchdog_update()
 		 * returns an error.
 		 */
+		if (old == new)
+			goto out;
+
 		err = proc_watchdog_update();
 	}
 out:
@@ -1064,7 +1067,7 @@ int proc_soft_watchdog(struct ctl_table *table, int write,
 int proc_watchdog_thresh(struct ctl_table *table, int write,
 			 void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-	int err, old;
+	int err, old, new;
 
 	get_online_cpus();
 	mutex_lock(&watchdog_proc_mutex);
@@ -1084,6 +1087,10 @@ int proc_watchdog_thresh(struct ctl_table *table, int write,
 	/*
 	 * Update the sample period. Restore on failure.
 	 */
+	new = ACCESS_ONCE(watchdog_thresh);
+	if (old == new)
+		goto out;
+
 	set_sample_period();
 	err = proc_watchdog_update();
 	if (err) {