[PATCH] hrtimer: round up relative start time on low-res arches
[linux-3.10.git] / kernel / hrtimer.c
index 2b6e175..5ae51f1 100644 (file)
@@ -418,8 +418,19 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
        /* Switch the timer base, if necessary: */
        new_base = switch_hrtimer_base(timer, base);
 
-       if (mode == HRTIMER_REL)
+       if (mode == HRTIMER_REL) {
                tim = ktime_add(tim, new_base->get_time());
+               /*
+                * CONFIG_TIME_LOW_RES is a temporary way for architectures
+                * to signal that they simply return xtime in
+                * do_gettimeoffset(). In this case we want to round up by
+                * resolution when starting a relative timer, to avoid short
+                * timeouts. This will go away with the GTOD framework.
+                */
+#ifdef CONFIG_TIME_LOW_RES
+               tim = ktime_add(tim, base->resolution);
+#endif
+       }
        timer->expires = tim;
 
        enqueue_hrtimer(timer, new_base);