[PATCH 5.14 013/334] hrtimer: Ensure timerfd notification for HIGHRES=n

Greg Kroah-Hartman
2021-09-13T14:21:14Z

From: Thomas Gleixner <tglx@linutronix.de>

[ Upstream commit 8c3b5e6ec0fee18bc2ce38d1dfe913413205f908 ]

If high resolution timers are disabled the timerfd notification about a
clock was set event is not happening for all cases which use
clock_was_set_delayed() because that's a NOP for HIGHRES=n, which is wrong.

Make clock_was_set_delayed() unconditially available to fix that.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210713135158.196661266@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/linux/hrtimer.h | 5 -----
kernel/time/hrtimer.c | 32 ++++++++++++++++----------------
kernel/time/tick-internal.h | 3 +++
3 files changed, 19 insertions(+), 21 deletions(-)

diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index bb5e7b0a4274..77295af72426 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -318,16 +318,12 @@ struct clock_event_device;

extern void hrtimer_interrupt(struct clock_event_device *dev);

-extern void clock_was_set_delayed(void);
-
extern unsigned int hrtimer_resolution;

#else

#define hrtimer_resolution (unsigned int)LOW_RES_NSEC

-static inline void clock_was_set_delayed(void) { }
-
#endif

static inline ktime_t
@@ -351,7 +347,6 @@ hrtimer_expires_remaining_adjusted(const struct hrtimer *timer)
timer->base->get_time());
}

-extern void clock_was_set(void);
#ifdef CONFIG_TIMERFD
extern void timerfd_clock_was_set(void);
#else
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index ba2e0d0a0e5a..5af758473488 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -758,22 +758,6 @@ static void hrtimer_switch_to_hres(void)
retrigger_next_event(NULL);
}

-static void clock_was_set_work(struct work_struct *work)
-{
- clock_was_set();
-}
-
-static DECLARE_WORK(hrtimer_work, clock_was_set_work);
-
-/*
- * Called from timekeeping and resume code to reprogram the hrtimer
- * interrupt device on all cpus.
- */
-void clock_was_set_delayed(void)
-{
- schedule_work(&hrtimer_work);
-}
-
#else

static inline int hrtimer_is_hres_enabled(void) { return 0; }
@@ -891,6 +875,22 @@ void clock_was_set(void)
timerfd_clock_was_set();
}

+static void clock_was_set_work(struct work_struct *work)
+{
+ clock_was_set();
+}
+
+static DECLARE_WORK(hrtimer_work, clock_was_set_work);
+
+/*
+ * Called from timekeeping and resume code to reprogram the hrtimer
+ * interrupt device on all cpus and to notify timerfd.
+ */
+void clock_was_set_delayed(void)
+{
+ schedule_work(&hrtimer_work);
+}
+
/*
* During resume we might have to reprogram the high resolution timer
* interrupt on all online CPUs. However, all other CPUs will be
diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
index 6a742a29e545..cd610faa2523 100644
--- a/kernel/time/tick-internal.h
+++ b/kernel/time/tick-internal.h
@@ -165,3 +165,6 @@ DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);

extern u64 get_next_timer_interrupt(unsigned long basej, u64 basem);
void timer_clear_idle(void);
+
+void clock_was_set(void);
+void clock_was_set_delayed(void);
--
2.30.2