@@ -823,6 +823,9 @@ static int proc_watchdog_common(int which, struct ctl_table *table, int write,
* Update the run state of the lockup detectors.
* Restore 'watchdog_enabled' on failure.
*/
+ if (old == new)
+ goto out;
+
err = proc_watchdog_update();
if (err)
watchdog_enabled = old;
@@ -868,7 +871,7 @@ 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;
mutex_lock(&watchdog_proc_mutex);
@@ -882,6 +885,10 @@ int proc_watchdog_thresh(struct ctl_table *table, int write,
* Update the sample period.
* Restore 'watchdog_thresh' on failure.
*/
+ new = ACCESS_ONCE(watchdog_thresh);
+ if (old == new)
+ goto out;
+
set_sample_period();
err = proc_watchdog_update();
if (err)