Merge tag 'timers-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer and timekeeping updates from Thomas Gleixner:

 - Expose CLOCK_TAI to instrumentation to aid with TSN debugging.

 - Ensure that the clockevent is stopped when there is no timer armed to
   avoid pointless wakeups.

 - Make the sched clock frequency handling and rounding consistent.

 - Provide a better debugobject hint for delayed works. The timer
   callback is always the same, which makes it difficult to identify the
   underlying work. Use the work function as a hint instead.

 - Move the timer specific sysctl code into the timer subsystem.

 - The usual set of improvements and cleanups

* tag 'timers-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timers: Provide a better debugobjects hint for delayed works
  time/sched_clock: Fix formatting of frequency reporting code
  time/sched_clock: Use Hz as the unit for clock rate reporting below 4kHz
  time/sched_clock: Round the frequency reported to nearest rather than down
  timekeeping: Consolidate fast timekeeper
  timekeeping: Annotate ktime_get_boot_fast_ns() with data_race()
  timers/nohz: Switch to ONESHOT_STOPPED in the low-res handler when the tick is stopped
  timekeeping: Introduce fast accessor to clock tai
  tracing/timer: Add missing argument documentation of trace points
  clocksource: Replace cpumask_weight() with cpumask_empty()
  timers: Move timer sysctl into the timer code
  clockevents: Use dedicated list iterator variable
  timers: Simplify calc_index()
  timers: Initialize base::next_expiry_recalc in timers_prepare_cpu()

1 files changed, 10 insertions, 2 deletions

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index d257721c68b8..58a11f859ac7 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -928,6 +928,8 @@ static void tick_nohz_stop_tick(struct tick_sched *ts, int cpu)
 	if (unlikely(expires == KTIME_MAX)) {
 		if (ts->nohz_mode == NOHZ_MODE_HIGHRES)
 			hrtimer_cancel(&ts->sched_timer);
+		else
+			tick_program_event(KTIME_MAX, 1);
 		return;
 	}
 
@@ -1364,9 +1366,15 @@ static void tick_nohz_handler(struct clock_event_device *dev)
 	tick_sched_do_timer(ts, now);
 	tick_sched_handle(ts, regs);
 
-	/* No need to reprogram if we are running tickless  */
-	if (unlikely(ts->tick_stopped))
+	if (unlikely(ts->tick_stopped)) {
+		/*
+		 * The clockevent device is not reprogrammed, so change the
+		 * clock event device to ONESHOT_STOPPED to avoid spurious
+		 * interrupts on devices which might not be truly one shot.
+		 */
+		tick_program_event(KTIME_MAX, 1);
 		return;
+	}
 
 	hrtimer_forward(&ts->sched_timer, now, TICK_NSEC);
 	tick_program_event(hrtimer_get_expires(&ts->sched_timer), 1);