tick: Sched: Restructure code

Get rid of one indentation level. Preparatory patch for a major
rework. No functional change.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Link: http://lkml.kernel.org/r/20150414203502.101563235@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

kernel/time/tick-sched.c

@@ -611,28 +611,26 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
 		}
 	}
 
-	/*
-	 * Do not stop the tick, if we are only one off (or less)
-	 * or if the cpu is required for RCU:
-	 */
-	if (!ts->tick_stopped && delta_jiffies <= 1)
+	if ((long)delta_jiffies <= 1) {
+		if (!ts->tick_stopped)
 			goto out;
-
-	/* Schedule the tick, if we are at least one jiffie off */
-	if ((long)delta_jiffies >= 1) {
+		if (delta_jiffies == 0) {
+			/* Tick is stopped, but required now. Enforce it */
+			tick_nohz_restart(ts, now);
+			goto out;
+		}
+	}
 
 	/*
-		 * If this cpu is the one which updates jiffies, then
-		 * give up the assignment and let it be taken by the
-		 * cpu which runs the tick timer next, which might be
-		 * this cpu as well. If we don't drop this here the
-		 * jiffies might be stale and do_timer() never
-		 * invoked. Keep track of the fact that it was the one
-		 * which had the do_timer() duty last. If this cpu is
-		 * the one which had the do_timer() duty last, we
-		 * limit the sleep time to the timekeeping
-		 * max_deferement value which we retrieved
-		 * above. Otherwise we can sleep as long as we want.
+	 * If this cpu is the one which updates jiffies, then give up
+	 * the assignment and let it be taken by the cpu which runs
+	 * the tick timer next, which might be this cpu as well. If we
+	 * don't drop this here the jiffies might be stale and
+	 * do_timer() never invoked. Keep track of the fact that it
+	 * was the one which had the do_timer() duty last. If this cpu
+	 * is the one which had the do_timer() duty last, we limit the
+	 * sleep time to the timekeeping max_deferement value which we
+	 * retrieved above. Otherwise we can sleep as long as we want.
 	 */
 	if (cpu == tick_do_timer_cpu) {
 		tick_do_timer_cpu = TICK_DO_TIMER_NONE;
@@ -645,18 +643,16 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
 	}
 
 #ifdef CONFIG_NO_HZ_FULL
-		if (!ts->inidle) {
-			time_delta = min(time_delta,
-					 scheduler_tick_max_deferment());
-		}
+	if (!ts->inidle)
+		time_delta = min(time_delta, scheduler_tick_max_deferment());
 #endif
 
 	/*
 	 * calculate the expiry time for the next timer wheel
-		 * timer. delta_jiffies >= NEXT_TIMER_MAX_DELTA signals
-		 * that there is no timer pending or at least extremely
-		 * far into the future (12 days for HZ=1000). In this
-		 * case we set the expiry to the end of time.
+	 * timer. delta_jiffies >= NEXT_TIMER_MAX_DELTA signals that
+	 * there is no timer pending or at least extremely far into
+	 * the future (12 days for HZ=1000). In this case we set the
+	 * expiry to the end of time.
 	 */
 	if (likely(delta_jiffies < NEXT_TIMER_MAX_DELTA)) {
 		/*
@@ -712,11 +708,6 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
 			      HRTIMER_MODE_ABS_PINNED);
 	else
 		tick_program_event(expires, 1);
-	} else {
-		/* Tick is stopped, but required now. Enforce it */
-		tick_nohz_restart(ts, now);
-	}
-
 out:
 	ts->next_jiffies = next_jiffies;
 	ts->last_jiffies = last_jiffies;