1 files changed, 33 insertions, 14 deletions

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index fa058510af9c..8ddf74e705d3 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -201,6 +201,27 @@ static inline void tick_sched_flag_clear(struct tick_sched *ts,
 	ts->flags &= ~flag;
 }
 
+/*
+ * Allow only one non-timekeeper CPU at a time update jiffies from
+ * the timer tick.
+ *
+ * Returns true if update was run.
+ */
+static bool tick_limited_update_jiffies64(struct tick_sched *ts, ktime_t now)
+{
+	static atomic_t in_progress;
+	int inp;
+
+	inp = atomic_read(&in_progress);
+	if (inp || !atomic_try_cmpxchg(&in_progress, &inp, 1))
+		return false;
+
+	if (ts->last_tick_jiffies == jiffies)
+		tick_do_update_jiffies64(now);
+	atomic_set(&in_progress, 0);
+	return true;
+}
+
 #define MAX_STALLED_JIFFIES 5
 
 static void tick_sched_do_timer(struct tick_sched *ts, ktime_t now)
@@ -239,10 +260,11 @@ static void tick_sched_do_timer(struct tick_sched *ts, ktime_t now)
 		ts->stalled_jiffies = 0;
 		ts->last_tick_jiffies = READ_ONCE(jiffies);
 	} else {
-		if (++ts->stalled_jiffies == MAX_STALLED_JIFFIES) {
-			tick_do_update_jiffies64(now);
-			ts->stalled_jiffies = 0;
-			ts->last_tick_jiffies = READ_ONCE(jiffies);
+		if (++ts->stalled_jiffies >= MAX_STALLED_JIFFIES) {
+			if (tick_limited_update_jiffies64(ts, now)) {
+				ts->stalled_jiffies = 0;
+				ts->last_tick_jiffies = READ_ONCE(jiffies);
+			}
 		}
 	}
 
@@ -1152,16 +1174,15 @@ static bool report_idle_softirq(void)
 			return false;
 	}
 
-	if (ratelimit >= 10)
-		return false;
-
 	/* On RT, softirq handling may be waiting on some lock */
 	if (local_bh_blocked())
 		return false;
 
-	pr_warn("NOHZ tick-stop error: local softirq work is pending, handler #%02x!!!\n",
-		pending);
-	ratelimit++;
+	if (ratelimit < 10) {
+		pr_warn("NOHZ tick-stop error: local softirq work is pending, handler #%02x!!!\n",
+			pending);
+		ratelimit++;
+	}
 
 	return true;
 }
@@ -1573,12 +1594,10 @@ void tick_setup_sched_timer(bool hrtimer)
 	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
 
 	/* Emulate tick processing via per-CPU hrtimers: */
-	hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
+	hrtimer_setup(&ts->sched_timer, tick_nohz_handler, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
 
-	if (IS_ENABLED(CONFIG_HIGH_RES_TIMERS) && hrtimer) {
+	if (IS_ENABLED(CONFIG_HIGH_RES_TIMERS) && hrtimer)
 		tick_sched_flag_set(ts, TS_FLAG_HIGHRES);
-		ts->sched_timer.function = tick_nohz_handler;
-	}
 
 	/* Get the next period (per-CPU) */
 	hrtimer_set_expires(&ts->sched_timer, tick_init_jiffy_update());