diff options
Diffstat (limited to 'kernel/hrtimer.c')
| -rw-r--r-- | kernel/hrtimer.c | 205 |
1 files changed, 174 insertions, 31 deletions
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index e379ef0e9c2..421be5fe5cc 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -43,6 +43,7 @@ #include <linux/tick.h> #include <linux/seq_file.h> #include <linux/err.h> +#include <linux/debugobjects.h> #include <asm/uaccess.h> @@ -153,15 +154,6 @@ static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base) } /* - * Helper function to check, whether the timer is running the callback - * function - */ -static inline int hrtimer_callback_running(struct hrtimer *timer) -{ - return timer->state & HRTIMER_STATE_CALLBACK; -} - -/* * Functions and macros which are different for UP/SMP systems are kept in a * single place */ @@ -342,6 +334,115 @@ ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs) return res; } +#ifdef CONFIG_DEBUG_OBJECTS_TIMERS + +static struct debug_obj_descr hrtimer_debug_descr; + +/* + * fixup_init is called when: + * - an active object is initialized + */ +static int hrtimer_fixup_init(void *addr, enum debug_obj_state state) +{ + struct hrtimer *timer = addr; + + switch (state) { + case ODEBUG_STATE_ACTIVE: + hrtimer_cancel(timer); + debug_object_init(timer, &hrtimer_debug_descr); + return 1; + default: + return 0; + } +} + +/* + * fixup_activate is called when: + * - an active object is activated + * - an unknown object is activated (might be a statically initialized object) + */ +static int hrtimer_fixup_activate(void *addr, enum debug_obj_state state) +{ + switch (state) { + + case ODEBUG_STATE_NOTAVAILABLE: + WARN_ON_ONCE(1); + return 0; + + case ODEBUG_STATE_ACTIVE: + WARN_ON(1); + + default: + return 0; + } +} + +/* + * fixup_free is called when: + * - an active object is freed + */ +static int hrtimer_fixup_free(void *addr, enum debug_obj_state state) +{ + struct hrtimer *timer = addr; + + switch (state) { + case ODEBUG_STATE_ACTIVE: + hrtimer_cancel(timer); + debug_object_free(timer, &hrtimer_debug_descr); + return 1; + default: + return 0; + } +} + +static struct debug_obj_descr hrtimer_debug_descr = { + .name = "hrtimer", + .fixup_init = hrtimer_fixup_init, + .fixup_activate = hrtimer_fixup_activate, + .fixup_free = hrtimer_fixup_free, +}; + +static inline void debug_hrtimer_init(struct hrtimer *timer) +{ + debug_object_init(timer, &hrtimer_debug_descr); +} + +static inline void debug_hrtimer_activate(struct hrtimer *timer) +{ + debug_object_activate(timer, &hrtimer_debug_descr); +} + +static inline void debug_hrtimer_deactivate(struct hrtimer *timer) +{ + debug_object_deactivate(timer, &hrtimer_debug_descr); +} + +static inline void debug_hrtimer_free(struct hrtimer *timer) +{ + debug_object_free(timer, &hrtimer_debug_descr); +} + +static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, + enum hrtimer_mode mode); + +void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id, + enum hrtimer_mode mode) +{ + debug_object_init_on_stack(timer, &hrtimer_debug_descr); + __hrtimer_init(timer, clock_id, mode); +} + +void destroy_hrtimer_on_stack(struct hrtimer *timer) +{ + debug_object_free(timer, &hrtimer_debug_descr); +} + +#else +static inline void debug_hrtimer_init(struct hrtimer *timer) { } +static inline void debug_hrtimer_activate(struct hrtimer *timer) { } +static inline void debug_hrtimer_deactivate(struct hrtimer *timer) { } +#endif + /* * Check, whether the timer is on the callback pending list */ @@ -567,6 +668,7 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer, /* Timer is expired, act upon the callback mode */ switch(timer->cb_mode) { case HRTIMER_CB_IRQSAFE_NO_RESTART: + debug_hrtimer_deactivate(timer); /* * We can call the callback from here. No restart * happens, so no danger of recursion @@ -581,6 +683,7 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer, * the tick timer in the softirq ! The calling site * takes care of this. */ + debug_hrtimer_deactivate(timer); return 1; case HRTIMER_CB_IRQSAFE: case HRTIMER_CB_SOFTIRQ: @@ -590,7 +693,6 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer, list_add_tail(&timer->cb_entry, &base->cpu_base->cb_pending); timer->state = HRTIMER_STATE_PENDING; - raise_softirq(HRTIMER_SOFTIRQ); return 1; default: BUG(); @@ -633,6 +735,11 @@ static int hrtimer_switch_to_hres(void) return 1; } +static inline void hrtimer_raise_softirq(void) +{ + raise_softirq(HRTIMER_SOFTIRQ); +} + #else static inline int hrtimer_hres_active(void) { return 0; } @@ -651,6 +758,7 @@ static inline int hrtimer_reprogram(struct hrtimer *timer, { return 0; } +static inline void hrtimer_raise_softirq(void) { } #endif /* CONFIG_HIGH_RES_TIMERS */ @@ -730,6 +838,8 @@ static void enqueue_hrtimer(struct hrtimer *timer, struct hrtimer *entry; int leftmost = 1; + debug_hrtimer_activate(timer); + /* * Find the right place in the rbtree: */ @@ -826,6 +936,7 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base) * reprogramming happens in the interrupt handler. This is a * rare case and less expensive than a smp call. */ + debug_hrtimer_deactivate(timer); timer_stats_hrtimer_clear_start_info(timer); reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases); __remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE, @@ -850,7 +961,7 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) { struct hrtimer_clock_base *base, *new_base; unsigned long flags; - int ret; + int ret, raise; base = lock_hrtimer_base(timer, &flags); @@ -873,6 +984,7 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) tim = ktime_add_safe(tim, base->resolution); #endif } + timer->expires = tim; timer_stats_hrtimer_set_start_info(timer); @@ -884,8 +996,18 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) enqueue_hrtimer(timer, new_base, new_base->cpu_base == &__get_cpu_var(hrtimer_bases)); + /* + * The timer may be expired and moved to the cb_pending + * list. We can not raise the softirq with base lock held due + * to a possible deadlock with runqueue lock. + */ + raise = timer->state == HRTIMER_STATE_PENDING; + unlock_hrtimer_base(timer, &flags); + if (raise) + hrtimer_raise_softirq(); + return ret; } EXPORT_SYMBOL_GPL(hrtimer_start); @@ -996,14 +1118,8 @@ ktime_t hrtimer_get_next_event(void) } #endif -/** - * hrtimer_init - initialize a timer to the given clock - * @timer: the timer to be initialized - * @clock_id: the clock to be used - * @mode: timer mode abs/rel - */ -void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, - enum hrtimer_mode mode) +static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, + enum hrtimer_mode mode) { struct hrtimer_cpu_base *cpu_base; @@ -1024,6 +1140,19 @@ void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, memset(timer->start_comm, 0, TASK_COMM_LEN); #endif } + +/** + * hrtimer_init - initialize a timer to the given clock + * @timer: the timer to be initialized + * @clock_id: the clock to be used + * @mode: timer mode abs/rel + */ +void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, + enum hrtimer_mode mode) +{ + debug_hrtimer_init(timer); + __hrtimer_init(timer, clock_id, mode); +} EXPORT_SYMBOL_GPL(hrtimer_init); /** @@ -1057,6 +1186,7 @@ static void run_hrtimer_pending(struct hrtimer_cpu_base *cpu_base) timer = list_entry(cpu_base->cb_pending.next, struct hrtimer, cb_entry); + debug_hrtimer_deactivate(timer); timer_stats_account_hrtimer(timer); fn = timer->function; @@ -1105,6 +1235,7 @@ static void __run_hrtimer(struct hrtimer *timer) enum hrtimer_restart (*fn)(struct hrtimer *); int restart; + debug_hrtimer_deactivate(timer); __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0); timer_stats_account_hrtimer(timer); @@ -1363,22 +1494,27 @@ long __sched hrtimer_nanosleep_restart(struct restart_block *restart) { struct hrtimer_sleeper t; struct timespec __user *rmtp; + int ret = 0; - hrtimer_init(&t.timer, restart->nanosleep.index, HRTIMER_MODE_ABS); + hrtimer_init_on_stack(&t.timer, restart->nanosleep.index, + HRTIMER_MODE_ABS); t.timer.expires.tv64 = restart->nanosleep.expires; if (do_nanosleep(&t, HRTIMER_MODE_ABS)) - return 0; + goto out; rmtp = restart->nanosleep.rmtp; if (rmtp) { - int ret = update_rmtp(&t.timer, rmtp); + ret = update_rmtp(&t.timer, rmtp); if (ret <= 0) - return ret; + goto out; } /* The other values in restart are already filled in */ - return -ERESTART_RESTARTBLOCK; + ret = -ERESTART_RESTARTBLOCK; +out: + destroy_hrtimer_on_stack(&t.timer); + return ret; } long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, @@ -1386,20 +1522,23 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, { struct restart_block *restart; struct hrtimer_sleeper t; + int ret = 0; - hrtimer_init(&t.timer, clockid, mode); + hrtimer_init_on_stack(&t.timer, clockid, mode); t.timer.expires = timespec_to_ktime(*rqtp); if (do_nanosleep(&t, mode)) - return 0; + goto out; /* Absolute timers do not update the rmtp value and restart: */ - if (mode == HRTIMER_MODE_ABS) - return -ERESTARTNOHAND; + if (mode == HRTIMER_MODE_ABS) { + ret = -ERESTARTNOHAND; + goto out; + } if (rmtp) { - int ret = update_rmtp(&t.timer, rmtp); + ret = update_rmtp(&t.timer, rmtp); if (ret <= 0) - return ret; + goto out; } restart = ¤t_thread_info()->restart_block; @@ -1408,7 +1547,10 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, restart->nanosleep.rmtp = rmtp; restart->nanosleep.expires = t.timer.expires.tv64; - return -ERESTART_RESTARTBLOCK; + ret = -ERESTART_RESTARTBLOCK; +out: + destroy_hrtimer_on_stack(&t.timer); + return ret; } asmlinkage long @@ -1453,6 +1595,7 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, while ((node = rb_first(&old_base->active))) { timer = rb_entry(node, struct hrtimer, node); BUG_ON(hrtimer_callback_running(timer)); + debug_hrtimer_deactivate(timer); __remove_hrtimer(timer, old_base, HRTIMER_STATE_INACTIVE, 0); timer->base = new_base; /* |