From a49b116dcb1265f238f3169507424257b0519069 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 3 Apr 2015 02:38:05 +0200 Subject: [PATCH] clockevents: Cleanup dead cpu explicitely clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the cleanup function for a dead cpu and invoke it directly from the cpu down code. Make it conditional on CPU_HOTPLUG as well. Temporary change, will be refined in the future. Signed-off-by: Thomas Gleixner [ Rebased, added clockevents_notify() removal ] Signed-off-by: Rafael J. Wysocki Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1735025.raBZdQHM3m@vostro.rjw.lan Signed-off-by: Ingo Molnar --- include/linux/clockchips.h | 6 ------ include/linux/tick.h | 2 ++ kernel/cpu.c | 1 + kernel/time/clockevents.c | 51 ++++++++++++++++++-------------------------- kernel/time/hrtimer.c | 3 --- kernel/time/tick-broadcast.c | 39 ++++++++++++++++----------------- kernel/time/tick-common.c | 6 +++--- kernel/time/tick-internal.h | 10 ++++----- 8 files changed, 52 insertions(+), 66 deletions(-) diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index f4bde22..96c280b 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -8,12 +8,6 @@ #ifndef _LINUX_CLOCKCHIPS_H #define _LINUX_CLOCKCHIPS_H -/* Clock event notification values */ -enum clock_event_nofitiers { - CLOCK_EVT_NOTIFY_ADD, - CLOCK_EVT_NOTIFY_CPU_DEAD, -}; - #ifdef CONFIG_GENERIC_CLOCKEVENTS # include diff --git a/include/linux/tick.h b/include/linux/tick.h index 2c68fa3..f8492da5 100644 --- a/include/linux/tick.h +++ b/include/linux/tick.h @@ -20,6 +20,7 @@ extern void tick_suspend_local(void); /* Should be core only, but XEN resume magic and ARM BL switcher require it */ extern void tick_resume_local(void); extern void tick_handover_do_timer(void); +extern void tick_cleanup_dead_cpu(int cpu); #else /* CONFIG_GENERIC_CLOCKEVENTS */ static inline void tick_init(void) { } static inline void tick_freeze(void) { } @@ -27,6 +28,7 @@ static inline void tick_unfreeze(void) { } static inline void tick_suspend_local(void) { } static inline void tick_resume_local(void) { } static inline void tick_handover_do_timer(void) { } +static inline void tick_cleanup_dead_cpu(int cpu) { } #endif /* !CONFIG_GENERIC_CLOCKEVENTS */ #ifdef CONFIG_TICK_ONESHOT diff --git a/kernel/cpu.c b/kernel/cpu.c index eba7eaa..82eea9c 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -419,6 +419,7 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) __cpu_die(cpu); /* CPU is completely dead: tell everyone. Too late to complain. */ + tick_cleanup_dead_cpu(cpu); cpu_notify_nofail(CPU_DEAD | mod, hcpu); check_for_tasks(cpu); diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index 88fb3b9..25d942d 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -642,49 +642,40 @@ void clockevents_resume(void) dev->resume(dev); } +#ifdef CONFIG_HOTPLUG_CPU /** - * clockevents_notify - notification about relevant events - * Returns 0 on success, any other value on error + * tick_cleanup_dead_cpu - Cleanup the tick and clockevents of a dead cpu */ -int clockevents_notify(unsigned long reason, void *arg) +void tick_cleanup_dead_cpu(int cpu) { struct clock_event_device *dev, *tmp; unsigned long flags; - int cpu, ret = 0; raw_spin_lock_irqsave(&clockevents_lock, flags); - switch (reason) { - case CLOCK_EVT_NOTIFY_CPU_DEAD: - tick_shutdown_broadcast_oneshot(arg); - tick_shutdown_broadcast(arg); - tick_shutdown(arg); - /* - * Unregister the clock event devices which were - * released from the users in the notify chain. - */ - list_for_each_entry_safe(dev, tmp, &clockevents_released, list) + tick_shutdown_broadcast_oneshot(cpu); + tick_shutdown_broadcast(cpu); + tick_shutdown(cpu); + /* + * Unregister the clock event devices which were + * released from the users in the notify chain. + */ + list_for_each_entry_safe(dev, tmp, &clockevents_released, list) + list_del(&dev->list); + /* + * Now check whether the CPU has left unused per cpu devices + */ + list_for_each_entry_safe(dev, tmp, &clockevent_devices, list) { + if (cpumask_test_cpu(cpu, dev->cpumask) && + cpumask_weight(dev->cpumask) == 1 && + !tick_is_broadcast_device(dev)) { + BUG_ON(dev->state != CLOCK_EVT_STATE_DETACHED); list_del(&dev->list); - /* - * Now check whether the CPU has left unused per cpu devices - */ - cpu = *((int *)arg); - list_for_each_entry_safe(dev, tmp, &clockevent_devices, list) { - if (cpumask_test_cpu(cpu, dev->cpumask) && - cpumask_weight(dev->cpumask) == 1 && - !tick_is_broadcast_device(dev)) { - BUG_ON(dev->state != CLOCK_EVT_STATE_DETACHED); - list_del(&dev->list); - } } - break; - default: - break; } raw_spin_unlock_irqrestore(&clockevents_lock, flags); - return ret; } -EXPORT_SYMBOL_GPL(clockevents_notify); +#endif #ifdef CONFIG_SYSFS struct bus_type clockevents_subsys = { diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 6a7a64e..76d4bd9 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -1709,11 +1709,8 @@ static int hrtimer_cpu_notify(struct notifier_block *self, #ifdef CONFIG_HOTPLUG_CPU case CPU_DEAD: case CPU_DEAD_FROZEN: - { - clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DEAD, &scpu); migrate_hrtimers(scpu); break; - } #endif default: diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index 55e43f2..7e8ca4f 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -410,14 +410,14 @@ void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast) dev->event_handler = tick_handle_periodic_broadcast; } +#ifdef CONFIG_HOTPLUG_CPU /* * Remove a CPU from broadcasting */ -void tick_shutdown_broadcast(unsigned int *cpup) +void tick_shutdown_broadcast(unsigned int cpu) { struct clock_event_device *bc; unsigned long flags; - unsigned int cpu = *cpup; raw_spin_lock_irqsave(&tick_broadcast_lock, flags); @@ -432,6 +432,7 @@ void tick_shutdown_broadcast(unsigned int *cpup) raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); } +#endif void tick_suspend_broadcast(void) { @@ -672,21 +673,6 @@ static void broadcast_shutdown_local(struct clock_event_device *bc, clockevents_set_state(dev, CLOCK_EVT_STATE_SHUTDOWN); } -void hotplug_cpu__broadcast_tick_pull(int deadcpu) -{ - struct clock_event_device *bc; - unsigned long flags; - - raw_spin_lock_irqsave(&tick_broadcast_lock, flags); - bc = tick_broadcast_device.evtdev; - - if (bc && broadcast_needs_cpu(bc, deadcpu)) { - /* This moves the broadcast assignment to this CPU: */ - clockevents_program_event(bc, bc->next_event, 1); - } - raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); -} - /** * tick_broadcast_oneshot_control - Enter/exit broadcast oneshot mode * @state: The target state (enter/exit) @@ -908,14 +894,28 @@ void tick_broadcast_switch_to_oneshot(void) raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); } +#ifdef CONFIG_HOTPLUG_CPU +void hotplug_cpu__broadcast_tick_pull(int deadcpu) +{ + struct clock_event_device *bc; + unsigned long flags; + + raw_spin_lock_irqsave(&tick_broadcast_lock, flags); + bc = tick_broadcast_device.evtdev; + + if (bc && broadcast_needs_cpu(bc, deadcpu)) { + /* This moves the broadcast assignment to this CPU: */ + clockevents_program_event(bc, bc->next_event, 1); + } + raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); +} /* * Remove a dead CPU from broadcasting */ -void tick_shutdown_broadcast_oneshot(unsigned int *cpup) +void tick_shutdown_broadcast_oneshot(unsigned int cpu) { unsigned long flags; - unsigned int cpu = *cpup; raw_spin_lock_irqsave(&tick_broadcast_lock, flags); @@ -929,6 +929,7 @@ void tick_shutdown_broadcast_oneshot(unsigned int *cpup) raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); } +#endif /* * Check, whether the broadcast device is in one shot mode diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index 055c868..fac3e98 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -348,7 +348,6 @@ void tick_handover_do_timer(void) TICK_DO_TIMER_NONE; } } -#endif /* * Shutdown an event device on a given cpu: @@ -357,9 +356,9 @@ void tick_handover_do_timer(void) * access the hardware device itself. * We just set the mode and remove it from the lists. */ -void tick_shutdown(unsigned int *cpup) +void tick_shutdown(unsigned int cpu) { - struct tick_device *td = &per_cpu(tick_cpu_device, *cpup); + struct tick_device *td = &per_cpu(tick_cpu_device, cpu); struct clock_event_device *dev = td->evtdev; td->mode = TICKDEV_MODE_PERIODIC; @@ -375,6 +374,7 @@ void tick_shutdown(unsigned int *cpup) td->evtdev = NULL; } } +#endif /** * tick_suspend_local - Suspend the local tick device diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h index aabcb5d..b64fdd8 100644 --- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -20,7 +20,7 @@ extern int tick_do_timer_cpu __read_mostly; extern void tick_setup_periodic(struct clock_event_device *dev, int broadcast); extern void tick_handle_periodic(struct clock_event_device *dev); extern void tick_check_new_device(struct clock_event_device *dev); -extern void tick_shutdown(unsigned int *cpup); +extern void tick_shutdown(unsigned int cpu); extern void tick_suspend(void); extern void tick_resume(void); extern bool tick_check_replacement(struct clock_event_device *curdev, @@ -52,7 +52,7 @@ 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 *cpup); +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); @@ -66,7 +66,7 @@ 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 *cpup) { } +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; } @@ -117,7 +117,7 @@ static inline int tick_check_oneshot_change(int allow_nohz) { return 0; } #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT) extern void tick_broadcast_setup_oneshot(struct clock_event_device *bc); extern void tick_broadcast_switch_to_oneshot(void); -extern void tick_shutdown_broadcast_oneshot(unsigned int *cpup); +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); @@ -125,7 +125,7 @@ extern struct cpumask *tick_get_broadcast_oneshot_mask(void); #else /* !(BROADCAST && ONESHOT): */ static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc) { BUG(); } static inline void tick_broadcast_switch_to_oneshot(void) { } -static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { } +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(); } -- 2.7.4