expiry = round_jiffies_up(req->deadline);
if (!timer_pending(&q->timeout) ||
- time_before(expiry, q->timeout.expires))
- mod_timer(&q->timeout, expiry);
+ time_before(expiry, q->timeout.expires)) {
+ unsigned long diff = q->timeout.expires - expiry;
+
+ /*
+ * Due to added timer slack to group timers, the timer
+ * will often be a little in front of what we asked for.
+ * So apply some tolerance here too, otherwise we keep
+ * modifying the timer because expires for value X
+ * will be X + something.
+ */
+ if (diff >= HZ / 2)
+ mod_timer(&q->timeout, expiry);
+ }
}