* Re: [WARNING] tick_handle_oneshot_broadcast() on !online CPU
2019-03-21 15:39 ` Thomas Gleixner
@ 2019-03-21 16:31 ` Valentin Schneider
2019-03-23 11:25 ` [tip:timers/core] tick: Remove outgoing CPU from broadcast masks tip-bot for Thomas Gleixner
2019-03-23 17:28 ` tip-bot for Thomas Gleixner
2 siblings, 0 replies; 5+ messages in thread
From: Valentin Schneider @ 2019-03-21 16:31 UTC (permalink / raw)
To: Thomas Gleixner; +Cc: linux-kernel, Frederic Weisbecker, Ingo Molnar
On 21/03/2019 15:39, Thomas Gleixner wrote:
> On Thu, 21 Mar 2019, Valentin Schneider wrote:
>> I stared at the code and did a bit of tracing, the sequence seems to be:
>>
>> ---
>> echo 0 > /sys/devices/system/cpu/cpu2/online
>>
>> takedown_cpu()
>> take_cpu_down()
>> __cpu_disable() (clears CPU in cpu_online_mask & cpu_active_mask)
>
> active_mask has been cleared long ago.
Right, dunno where I picked that up...
[...]
> Hmm. This only seems to be an issue with forced broadcast. The dynamic
> broadcast stuff does not have that problem as the CPU is obviously not idle
> while going down.
>
> Patch below (completely untested) should fix it.
>
> Thanks,
>
No more warns after a few hundred iterations, and the tick_offline_cpu()
in take_cpu_down() makes sense to me.
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Thanks!
Valentin
> tglx
>
> 8<---------------
>
> --- a/include/linux/tick.h
> +++ b/include/linux/tick.h
> @@ -68,6 +68,12 @@ extern void tick_broadcast_control(enum
> static inline void tick_broadcast_control(enum tick_broadcast_mode mode) { }
> #endif /* BROADCAST */
>
> +#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_HOTPLUG_CPU)
> +extern void tick_offline_cpu(unsigned int cpu);
> +#else
> +static inline void tick_offline_cpu(unsigned int cpu) { }
> +#endif
> +
> #ifdef CONFIG_GENERIC_CLOCKEVENTS
> extern int tick_broadcast_oneshot_control(enum tick_broadcast_state state);
> #else
> --- a/kernel/cpu.c
> +++ b/kernel/cpu.c
> @@ -844,6 +844,8 @@ static int take_cpu_down(void *_param)
>
> /* Give up timekeeping duties */
> tick_handover_do_timer();
> + /* Remove CPU from timer broadcasting */
> + tick_offline_cpu(cpu);
> /* Park the stopper thread */
> stop_machine_park(cpu);
> return 0;
> --- a/kernel/time/clockevents.c
> +++ b/kernel/time/clockevents.c
> @@ -611,6 +611,22 @@ void clockevents_resume(void)
> }
>
> #ifdef CONFIG_HOTPLUG_CPU
> +
> +# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
> +/**
> + * tick_offline_cpu - Take CPU out of the broadcast mechanism
> + * @cpu: The outgoing CPU
> + *
> + * Called on the outgoing CPU after it took itself offline.
> + */
> +void tick_offline_cpu(unsigned int cpu)
> +{
> + raw_spin_lock(&clockevents_lock);
> + tick_broadcast_offline(cpu);
> + raw_spin_unlock(&clockevents_lock);
> +}
> +# endif
> +
> /**
> * tick_cleanup_dead_cpu - Cleanup the tick and clockevents of a dead cpu
> */
> @@ -621,8 +637,6 @@ void tick_cleanup_dead_cpu(int cpu)
>
> raw_spin_lock_irqsave(&clockevents_lock, flags);
>
> - tick_shutdown_broadcast_oneshot(cpu);
> - tick_shutdown_broadcast(cpu);
> tick_shutdown(cpu);
> /*
> * Unregister the clock event devices which were
> --- a/kernel/time/tick-broadcast.c
> +++ b/kernel/time/tick-broadcast.c
> @@ -36,10 +36,12 @@ static __cacheline_aligned_in_smp DEFINE
> static void tick_broadcast_setup_oneshot(struct clock_event_device *bc);
> static void tick_broadcast_clear_oneshot(int cpu);
> static void tick_resume_broadcast_oneshot(struct clock_event_device *bc);
> +static void tick_broadcast_oneshot_offline(unsigned int cpu);
> #else
> static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc) { BUG(); }
> static inline void tick_broadcast_clear_oneshot(int cpu) { }
> static inline void tick_resume_broadcast_oneshot(struct clock_event_device *bc) { }
> +static inline void tick_broadcast_oneshot_offline(unsigned int cpu) { }
> #endif
>
> /*
> @@ -444,8 +446,6 @@ void tick_shutdown_broadcast(unsigned in
> raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
>
> bc = tick_broadcast_device.evtdev;
> - cpumask_clear_cpu(cpu, tick_broadcast_mask);
> - cpumask_clear_cpu(cpu, tick_broadcast_on);
>
> if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) {
> if (bc && cpumask_empty(tick_broadcast_mask))
> @@ -454,6 +454,16 @@ void tick_shutdown_broadcast(unsigned in
>
> raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
> }
> +
> +void tick_broadcast_offline(unsigned int cpu)
> +{
> + raw_spin_lock(&tick_broadcast_lock);
> + cpumask_clear_cpu(cpu, tick_broadcast_mask);
> + cpumask_clear_cpu(cpu, tick_broadcast_on);
> + tick_broadcast_oneshot_offline(cpu);
> + raw_spin_unlock(&tick_broadcast_lock);
> +}
> +
> #endif
>
> void tick_suspend_broadcast(void)
> @@ -950,14 +960,10 @@ void hotplug_cpu__broadcast_tick_pull(in
> }
>
> /*
> - * Remove a dead CPU from broadcasting
> + * Remove a dying CPU from broadcasting
> */
> -void tick_shutdown_broadcast_oneshot(unsigned int cpu)
> +static void tick_broadcast_oneshot_offline(unsigned int cpu)
> {
> - unsigned long flags;
> -
> - raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
> -
> /*
> * Clear the broadcast masks for the dead cpu, but do not stop
> * the broadcast device!
> @@ -965,8 +971,6 @@ void tick_shutdown_broadcast_oneshot(uns
> cpumask_clear_cpu(cpu, tick_broadcast_oneshot_mask);
> cpumask_clear_cpu(cpu, tick_broadcast_pending_mask);
> cpumask_clear_cpu(cpu, tick_broadcast_force_mask);
> -
> - raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
> }
> #endif
>
> --- a/kernel/time/tick-internal.h
> +++ b/kernel/time/tick-internal.h
> @@ -64,7 +64,6 @@ extern ssize_t sysfs_get_uname(const cha
> extern int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu);
> extern void tick_install_broadcast_device(struct clock_event_device *dev);
> extern int tick_is_broadcast_device(struct clock_event_device *dev);
> -extern void tick_shutdown_broadcast(unsigned int cpu);
> extern void tick_suspend_broadcast(void);
> extern void tick_resume_broadcast(void);
> extern bool tick_resume_check_broadcast(void);
> @@ -78,7 +77,6 @@ static inline void tick_install_broadcas
> static inline int tick_is_broadcast_device(struct clock_event_device *dev) { return 0; }
> static inline int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) { return 0; }
> static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }
> -static inline void tick_shutdown_broadcast(unsigned int cpu) { }
> static inline void tick_suspend_broadcast(void) { }
> static inline void tick_resume_broadcast(void) { }
> static inline bool tick_resume_check_broadcast(void) { return false; }
> @@ -128,19 +126,23 @@ static inline int tick_check_oneshot_cha
> /* Functions related to oneshot broadcasting */
> #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
> extern void tick_broadcast_switch_to_oneshot(void);
> -extern void tick_shutdown_broadcast_oneshot(unsigned int cpu);
> extern int tick_broadcast_oneshot_active(void);
> extern void tick_check_oneshot_broadcast_this_cpu(void);
> bool tick_broadcast_oneshot_available(void);
> extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
> #else /* !(BROADCAST && ONESHOT): */
> static inline void tick_broadcast_switch_to_oneshot(void) { }
> -static inline void tick_shutdown_broadcast_oneshot(unsigned int cpu) { }
> static inline int tick_broadcast_oneshot_active(void) { return 0; }
> static inline void tick_check_oneshot_broadcast_this_cpu(void) { }
> static inline bool tick_broadcast_oneshot_available(void) { return tick_oneshot_possible(); }
> #endif /* !(BROADCAST && ONESHOT) */
>
> +#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_HOTPLUG_CPU)
> +extern void tick_broadcast_offline(unsigned int cpu);
> +#else
> +static inline void tick_broadcast_offline(unsigned int cpu) { }
> +#endif
> +
> /* NO_HZ_FULL internal */
> #ifdef CONFIG_NO_HZ_FULL
> extern void tick_nohz_init(void);
>
^ permalink raw reply [flat|nested] 5+ messages in thread* [tip:timers/core] tick: Remove outgoing CPU from broadcast masks
2019-03-21 15:39 ` Thomas Gleixner
2019-03-21 16:31 ` Valentin Schneider
@ 2019-03-23 11:25 ` tip-bot for Thomas Gleixner
2019-03-23 17:28 ` tip-bot for Thomas Gleixner
2 siblings, 0 replies; 5+ messages in thread
From: tip-bot for Thomas Gleixner @ 2019-03-23 11:25 UTC (permalink / raw)
To: linux-tip-commits
Cc: fweisbec, tglx, valentin.schneider, hpa, mingo, linux-kernel
Commit-ID: 973f88ca8b159592685b6ccedb0b91db376bf20d
Gitweb: https://git.kernel.org/tip/973f88ca8b159592685b6ccedb0b91db376bf20d
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Thu, 21 Mar 2019 16:39:20 +0100
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Sat, 23 Mar 2019 12:21:32 +0100
tick: Remove outgoing CPU from broadcast masks
Valentin reported that unplugging a CPU occasionally results in a warning
in the tick broadcast code which is triggered when an offline CPU is in the
broadcast mask.
This happens because the outgoing CPU is not removing itself from the
broadcast masks, especially not from the broadcast_force_mask. The removal
happens on the control CPU after the outgoing CPU is dead. It's a long
standing issue, but the warning is harmless.
Rework the hotplug mechanism so that the outgoing CPU removes itself from
the broadcast masks after disabling interrupts and removing itself from the
online mask.
Reported-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1903211540180.1784@nanos.tec.linutronix.de
---
include/linux/tick.h | 6 ++++++
kernel/cpu.c | 2 ++
kernel/time/clockevents.c | 18 ++++++++++++++++--
kernel/time/tick-broadcast.c | 24 ++++++++++++++----------
kernel/time/tick-internal.h | 10 ++++++----
5 files changed, 44 insertions(+), 16 deletions(-)
diff --git a/include/linux/tick.h b/include/linux/tick.h
index 55388ab45fd4..76acb48acdb7 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -68,6 +68,12 @@ extern void tick_broadcast_control(enum tick_broadcast_mode mode);
static inline void tick_broadcast_control(enum tick_broadcast_mode mode) { }
#endif /* BROADCAST */
+#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_HOTPLUG_CPU)
+extern void tick_offline_cpu(unsigned int cpu);
+#else
+static inline void tick_offline_cpu(unsigned int cpu) { }
+#endif
+
#ifdef CONFIG_GENERIC_CLOCKEVENTS
extern int tick_broadcast_oneshot_control(enum tick_broadcast_state state);
#else
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 025f419d16f6..f69ba38573c2 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -844,6 +844,8 @@ static int take_cpu_down(void *_param)
/* Give up timekeeping duties */
tick_handover_do_timer();
+ /* Remove CPU from timer broadcasting */
+ tick_offline_cpu(cpu);
/* Park the stopper thread */
stop_machine_park(cpu);
return 0;
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 5e77662dd2d9..f5490222e134 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -611,6 +611,22 @@ void clockevents_resume(void)
}
#ifdef CONFIG_HOTPLUG_CPU
+
+# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+/**
+ * tick_offline_cpu - Take CPU out of the broadcast mechanism
+ * @cpu: The outgoing CPU
+ *
+ * Called on the outgoing CPU after it took itself offline.
+ */
+void tick_offline_cpu(unsigned int cpu)
+{
+ raw_spin_lock(&clockevents_lock);
+ tick_broadcast_offline(cpu);
+ raw_spin_unlock(&clockevents_lock);
+}
+# endif
+
/**
* tick_cleanup_dead_cpu - Cleanup the tick and clockevents of a dead cpu
*/
@@ -621,8 +637,6 @@ void tick_cleanup_dead_cpu(int cpu)
raw_spin_lock_irqsave(&clockevents_lock, flags);
- tick_shutdown_broadcast_oneshot(cpu);
- tick_shutdown_broadcast(cpu);
tick_shutdown(cpu);
/*
* Unregister the clock event devices which were
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index ee834d4fb814..a4705191d344 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -36,10 +36,12 @@ static __cacheline_aligned_in_smp DEFINE_RAW_SPINLOCK(tick_broadcast_lock);
static void tick_broadcast_setup_oneshot(struct clock_event_device *bc);
static void tick_broadcast_clear_oneshot(int cpu);
static void tick_resume_broadcast_oneshot(struct clock_event_device *bc);
+static void tick_broadcast_oneshot_offline(unsigned int cpu);
#else
static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc) { BUG(); }
static inline void tick_broadcast_clear_oneshot(int cpu) { }
static inline void tick_resume_broadcast_oneshot(struct clock_event_device *bc) { }
+static inline void tick_broadcast_oneshot_offline(unsigned int cpu) { }
#endif
/*
@@ -444,8 +446,6 @@ void tick_shutdown_broadcast(unsigned int cpu)
raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
bc = tick_broadcast_device.evtdev;
- cpumask_clear_cpu(cpu, tick_broadcast_mask);
- cpumask_clear_cpu(cpu, tick_broadcast_on);
if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) {
if (bc && cpumask_empty(tick_broadcast_mask))
@@ -454,6 +454,16 @@ void tick_shutdown_broadcast(unsigned int cpu)
raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}
+
+void tick_broadcast_offline(unsigned int cpu)
+{
+ raw_spin_lock(&tick_broadcast_lock);
+ cpumask_clear_cpu(cpu, tick_broadcast_mask);
+ cpumask_clear_cpu(cpu, tick_broadcast_on);
+ tick_broadcast_oneshot_offline(cpu);
+ raw_spin_unlock(&tick_broadcast_lock);
+}
+
#endif
void tick_suspend_broadcast(void)
@@ -950,14 +960,10 @@ void hotplug_cpu__broadcast_tick_pull(int deadcpu)
}
/*
- * Remove a dead CPU from broadcasting
+ * Remove a dying CPU from broadcasting
*/
-void tick_shutdown_broadcast_oneshot(unsigned int cpu)
+static void tick_broadcast_oneshot_offline(unsigned int cpu)
{
- unsigned long flags;
-
- raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
-
/*
* Clear the broadcast masks for the dead cpu, but do not stop
* the broadcast device!
@@ -965,8 +971,6 @@ void tick_shutdown_broadcast_oneshot(unsigned int cpu)
cpumask_clear_cpu(cpu, tick_broadcast_oneshot_mask);
cpumask_clear_cpu(cpu, tick_broadcast_pending_mask);
cpumask_clear_cpu(cpu, tick_broadcast_force_mask);
-
- raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}
#endif
diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
index e277284c2831..7b2496136729 100644
--- a/kernel/time/tick-internal.h
+++ b/kernel/time/tick-internal.h
@@ -64,7 +64,6 @@ extern ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt);
extern int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu);
extern void tick_install_broadcast_device(struct clock_event_device *dev);
extern int tick_is_broadcast_device(struct clock_event_device *dev);
-extern void tick_shutdown_broadcast(unsigned int cpu);
extern void tick_suspend_broadcast(void);
extern void tick_resume_broadcast(void);
extern bool tick_resume_check_broadcast(void);
@@ -78,7 +77,6 @@ static inline void tick_install_broadcast_device(struct clock_event_device *dev)
static inline int tick_is_broadcast_device(struct clock_event_device *dev) { return 0; }
static inline int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) { return 0; }
static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }
-static inline void tick_shutdown_broadcast(unsigned int cpu) { }
static inline void tick_suspend_broadcast(void) { }
static inline void tick_resume_broadcast(void) { }
static inline bool tick_resume_check_broadcast(void) { return false; }
@@ -128,19 +126,23 @@ static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
/* Functions related to oneshot broadcasting */
#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
extern void tick_broadcast_switch_to_oneshot(void);
-extern void tick_shutdown_broadcast_oneshot(unsigned int cpu);
extern int tick_broadcast_oneshot_active(void);
extern void tick_check_oneshot_broadcast_this_cpu(void);
bool tick_broadcast_oneshot_available(void);
extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
#else /* !(BROADCAST && ONESHOT): */
static inline void tick_broadcast_switch_to_oneshot(void) { }
-static inline void tick_shutdown_broadcast_oneshot(unsigned int cpu) { }
static inline int tick_broadcast_oneshot_active(void) { return 0; }
static inline void tick_check_oneshot_broadcast_this_cpu(void) { }
static inline bool tick_broadcast_oneshot_available(void) { return tick_oneshot_possible(); }
#endif /* !(BROADCAST && ONESHOT) */
+#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_HOTPLUG_CPU)
+extern void tick_broadcast_offline(unsigned int cpu);
+#else
+static inline void tick_broadcast_offline(unsigned int cpu) { }
+#endif
+
/* NO_HZ_FULL internal */
#ifdef CONFIG_NO_HZ_FULL
extern void tick_nohz_init(void);
^ permalink raw reply related [flat|nested] 5+ messages in thread* [tip:timers/core] tick: Remove outgoing CPU from broadcast masks
2019-03-21 15:39 ` Thomas Gleixner
2019-03-21 16:31 ` Valentin Schneider
2019-03-23 11:25 ` [tip:timers/core] tick: Remove outgoing CPU from broadcast masks tip-bot for Thomas Gleixner
@ 2019-03-23 17:28 ` tip-bot for Thomas Gleixner
2 siblings, 0 replies; 5+ messages in thread
From: tip-bot for Thomas Gleixner @ 2019-03-23 17:28 UTC (permalink / raw)
To: linux-tip-commits
Cc: hpa, linux-kernel, tglx, valentin.schneider, fweisbec, mingo
Commit-ID: 1b72d43237980eab9b6ae6bb8181e51c840377e6
Gitweb: https://git.kernel.org/tip/1b72d43237980eab9b6ae6bb8181e51c840377e6
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Thu, 21 Mar 2019 16:39:20 +0100
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Sat, 23 Mar 2019 18:26:43 +0100
tick: Remove outgoing CPU from broadcast masks
Valentin reported that unplugging a CPU occasionally results in a warning
in the tick broadcast code which is triggered when an offline CPU is in the
broadcast mask.
This happens because the outgoing CPU is not removing itself from the
broadcast masks, especially not from the broadcast_force_mask. The removal
happens on the control CPU after the outgoing CPU is dead. It's a long
standing issue, but the warning is harmless.
Rework the hotplug mechanism so that the outgoing CPU removes itself from
the broadcast masks after disabling interrupts and removing itself from the
online mask.
Reported-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1903211540180.1784@nanos.tec.linutronix.de
---
include/linux/tick.h | 6 ++++++
kernel/cpu.c | 2 ++
kernel/time/clockevents.c | 18 ++++++++++++++++--
kernel/time/tick-broadcast.c | 40 +++++++++++++++++++---------------------
kernel/time/tick-internal.h | 10 ++++++----
5 files changed, 49 insertions(+), 27 deletions(-)
diff --git a/include/linux/tick.h b/include/linux/tick.h
index 55388ab45fd4..76acb48acdb7 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -68,6 +68,12 @@ extern void tick_broadcast_control(enum tick_broadcast_mode mode);
static inline void tick_broadcast_control(enum tick_broadcast_mode mode) { }
#endif /* BROADCAST */
+#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_HOTPLUG_CPU)
+extern void tick_offline_cpu(unsigned int cpu);
+#else
+static inline void tick_offline_cpu(unsigned int cpu) { }
+#endif
+
#ifdef CONFIG_GENERIC_CLOCKEVENTS
extern int tick_broadcast_oneshot_control(enum tick_broadcast_state state);
#else
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 025f419d16f6..f69ba38573c2 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -844,6 +844,8 @@ static int take_cpu_down(void *_param)
/* Give up timekeeping duties */
tick_handover_do_timer();
+ /* Remove CPU from timer broadcasting */
+ tick_offline_cpu(cpu);
/* Park the stopper thread */
stop_machine_park(cpu);
return 0;
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 5e77662dd2d9..f5490222e134 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -611,6 +611,22 @@ void clockevents_resume(void)
}
#ifdef CONFIG_HOTPLUG_CPU
+
+# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+/**
+ * tick_offline_cpu - Take CPU out of the broadcast mechanism
+ * @cpu: The outgoing CPU
+ *
+ * Called on the outgoing CPU after it took itself offline.
+ */
+void tick_offline_cpu(unsigned int cpu)
+{
+ raw_spin_lock(&clockevents_lock);
+ tick_broadcast_offline(cpu);
+ raw_spin_unlock(&clockevents_lock);
+}
+# endif
+
/**
* tick_cleanup_dead_cpu - Cleanup the tick and clockevents of a dead cpu
*/
@@ -621,8 +637,6 @@ void tick_cleanup_dead_cpu(int cpu)
raw_spin_lock_irqsave(&clockevents_lock, flags);
- tick_shutdown_broadcast_oneshot(cpu);
- tick_shutdown_broadcast(cpu);
tick_shutdown(cpu);
/*
* Unregister the clock event devices which were
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index ee834d4fb814..0283523de045 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -36,10 +36,12 @@ static __cacheline_aligned_in_smp DEFINE_RAW_SPINLOCK(tick_broadcast_lock);
static void tick_broadcast_setup_oneshot(struct clock_event_device *bc);
static void tick_broadcast_clear_oneshot(int cpu);
static void tick_resume_broadcast_oneshot(struct clock_event_device *bc);
+static void tick_broadcast_oneshot_offline(unsigned int cpu);
#else
static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc) { BUG(); }
static inline void tick_broadcast_clear_oneshot(int cpu) { }
static inline void tick_resume_broadcast_oneshot(struct clock_event_device *bc) { }
+static inline void tick_broadcast_oneshot_offline(unsigned int cpu) { }
#endif
/*
@@ -433,27 +435,29 @@ void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast)
}
#ifdef CONFIG_HOTPLUG_CPU
-/*
- * Remove a CPU from broadcasting
- */
-void tick_shutdown_broadcast(unsigned int cpu)
+static void tick_shutdown_broadcast(void)
{
- struct clock_event_device *bc;
- unsigned long flags;
-
- raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
-
- bc = tick_broadcast_device.evtdev;
- cpumask_clear_cpu(cpu, tick_broadcast_mask);
- cpumask_clear_cpu(cpu, tick_broadcast_on);
+ struct clock_event_device *bc = tick_broadcast_device.evtdev;
if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) {
if (bc && cpumask_empty(tick_broadcast_mask))
clockevents_shutdown(bc);
}
+}
- raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
+/*
+ * Remove a CPU from broadcasting
+ */
+void tick_broadcast_offline(unsigned int cpu)
+{
+ raw_spin_lock(&tick_broadcast_lock);
+ cpumask_clear_cpu(cpu, tick_broadcast_mask);
+ cpumask_clear_cpu(cpu, tick_broadcast_on);
+ tick_broadcast_oneshot_offline(cpu);
+ tick_shutdown_broadcast();
+ raw_spin_unlock(&tick_broadcast_lock);
}
+
#endif
void tick_suspend_broadcast(void)
@@ -950,14 +954,10 @@ void hotplug_cpu__broadcast_tick_pull(int deadcpu)
}
/*
- * Remove a dead CPU from broadcasting
+ * Remove a dying CPU from broadcasting
*/
-void tick_shutdown_broadcast_oneshot(unsigned int cpu)
+static void tick_broadcast_oneshot_offline(unsigned int cpu)
{
- unsigned long flags;
-
- raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
-
/*
* Clear the broadcast masks for the dead cpu, but do not stop
* the broadcast device!
@@ -965,8 +965,6 @@ void tick_shutdown_broadcast_oneshot(unsigned int cpu)
cpumask_clear_cpu(cpu, tick_broadcast_oneshot_mask);
cpumask_clear_cpu(cpu, tick_broadcast_pending_mask);
cpumask_clear_cpu(cpu, tick_broadcast_force_mask);
-
- raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}
#endif
diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
index e277284c2831..7b2496136729 100644
--- a/kernel/time/tick-internal.h
+++ b/kernel/time/tick-internal.h
@@ -64,7 +64,6 @@ extern ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt);
extern int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu);
extern void tick_install_broadcast_device(struct clock_event_device *dev);
extern int tick_is_broadcast_device(struct clock_event_device *dev);
-extern void tick_shutdown_broadcast(unsigned int cpu);
extern void tick_suspend_broadcast(void);
extern void tick_resume_broadcast(void);
extern bool tick_resume_check_broadcast(void);
@@ -78,7 +77,6 @@ static inline void tick_install_broadcast_device(struct clock_event_device *dev)
static inline int tick_is_broadcast_device(struct clock_event_device *dev) { return 0; }
static inline int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) { return 0; }
static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }
-static inline void tick_shutdown_broadcast(unsigned int cpu) { }
static inline void tick_suspend_broadcast(void) { }
static inline void tick_resume_broadcast(void) { }
static inline bool tick_resume_check_broadcast(void) { return false; }
@@ -128,19 +126,23 @@ static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
/* Functions related to oneshot broadcasting */
#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
extern void tick_broadcast_switch_to_oneshot(void);
-extern void tick_shutdown_broadcast_oneshot(unsigned int cpu);
extern int tick_broadcast_oneshot_active(void);
extern void tick_check_oneshot_broadcast_this_cpu(void);
bool tick_broadcast_oneshot_available(void);
extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
#else /* !(BROADCAST && ONESHOT): */
static inline void tick_broadcast_switch_to_oneshot(void) { }
-static inline void tick_shutdown_broadcast_oneshot(unsigned int cpu) { }
static inline int tick_broadcast_oneshot_active(void) { return 0; }
static inline void tick_check_oneshot_broadcast_this_cpu(void) { }
static inline bool tick_broadcast_oneshot_available(void) { return tick_oneshot_possible(); }
#endif /* !(BROADCAST && ONESHOT) */
+#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_HOTPLUG_CPU)
+extern void tick_broadcast_offline(unsigned int cpu);
+#else
+static inline void tick_broadcast_offline(unsigned int cpu) { }
+#endif
+
/* NO_HZ_FULL internal */
#ifdef CONFIG_NO_HZ_FULL
extern void tick_nohz_init(void);
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