nohz: Gather tick_sched booleans under a common flag field

Optimize the space and leave plenty of room for further flags.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
[ rjw: Do not use __this_cpu_read() to access tick_stopped and add
       got_idle_tick to avoid overloading inidle ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

kernel/time/tick-sched.c

@@ -465,7 +465,9 @@ __setup("nohz=", setup_tick_nohz);
 
 bool tick_nohz_tick_stopped(void)
 {
-	return __this_cpu_read(tick_cpu_sched.tick_stopped);
+	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
+
+	return ts->tick_stopped;
 }
 
 bool tick_nohz_tick_stopped_cpu(int cpu)
@@ -1014,8 +1016,8 @@ bool tick_nohz_idle_got_tick(void)
 {
 	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
 
-	if (ts->inidle > 1) {
-		ts->inidle = 1;
+	if (ts->got_idle_tick) {
+		ts->got_idle_tick = 0;
 		return true;
 	}
 	return false;
@@ -1161,7 +1163,7 @@ static void tick_nohz_handler(struct clock_event_device *dev)
 	ktime_t now = ktime_get();
 
 	if (ts->inidle)
-		ts->inidle = 2;
+		ts->got_idle_tick = 1;
 
 	dev->next_event = KTIME_MAX;
 
@@ -1261,7 +1263,7 @@ static enum hrtimer_restart tick_sched_timer(struct hrtimer *timer)
 	ktime_t now = ktime_get();
 
 	if (ts->inidle)
-		ts->inidle = 2;
+		ts->got_idle_tick = 1;
 
 	tick_sched_do_timer(now);
 

kernel/time/tick-sched.h

@@ -41,19 +41,24 @@ enum tick_nohz_mode {
  * @timer_expires:	Anticipated timer expiration time (in case sched tick is stopped)
  * @timer_expires_base:	Base time clock monotonic for @timer_expires
  * @do_timer_lst:	CPU was the last one doing do_timer before going idle
+ * @got_idle_tick:	Tick timer function has run with @inidle set
  */
 struct tick_sched {
 	struct hrtimer			sched_timer;
 	unsigned long			check_clocks;
 	enum tick_nohz_mode		nohz_mode;
+
+	unsigned int			inidle		: 1;
+	unsigned int			tick_stopped	: 1;
+	unsigned int			idle_active	: 1;
+	unsigned int			do_timer_last	: 1;
+	unsigned int			got_idle_tick	: 1;
+
 	ktime_t				last_tick;
 	ktime_t				next_tick;
-	int				inidle;
-	int				tick_stopped;
 	unsigned long			idle_jiffies;
 	unsigned long			idle_calls;
 	unsigned long			idle_sleeps;
-	int				idle_active;
 	ktime_t				idle_entrytime;
 	ktime_t				idle_waketime;
 	ktime_t				idle_exittime;
@@ -64,7 +69,6 @@ struct tick_sched {
 	u64				timer_expires_base;
 	u64				next_timer;
 	ktime_t				idle_expires;
-	int				do_timer_last;
 	atomic_t			tick_dep_mask;
 };