X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Fhrtimer.c;h=cdec83e722fa1b80ee0af0f828d8e47532431a20;hb=07454bfff151d2465ada809bbaddf3548cc1097c;hp=dea4c9124ac808b872d43a3dd83c15fc7cbb38a9;hpb=f05c463be51898e745c4aa8245b05e25d73fa975;p=pandora-kernel.git diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index dea4c9124ac8..cdec83e722fa 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -43,6 +43,7 @@ #include #include #include +#include #include @@ -152,15 +153,6 @@ static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base) ktime_add(xtim, tomono); } -/* - * 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 @@ -308,11 +300,10 @@ EXPORT_SYMBOL_GPL(ktime_sub_ns); */ u64 ktime_divns(const ktime_t kt, s64 div) { - u64 dclc, inc, dns; + u64 dclc; int sft = 0; - dclc = dns = ktime_to_ns(kt); - inc = div; + dclc = ktime_to_ns(kt); /* Make sure the divisor is less than 2^32: */ while (div >> 32) { sft++; @@ -342,6 +333,115 @@ 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 */ @@ -522,7 +622,7 @@ static void retrigger_next_event(void *arg) void clock_was_set(void) { /* Retrigger the CPU local events everywhere */ - on_each_cpu(retrigger_next_event, NULL, 0, 1); + on_each_cpu(retrigger_next_event, NULL, 1); } /* @@ -531,8 +631,6 @@ void clock_was_set(void) */ void hres_timers_resume(void) { - WARN_ON_ONCE(num_online_cpus() > 1); - /* Retrigger the CPU local events: */ retrigger_next_event(NULL); } @@ -567,20 +665,23 @@ 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 */ BUG_ON(timer->function(timer) != HRTIMER_NORESTART); return 1; - case HRTIMER_CB_IRQSAFE_NO_SOFTIRQ: + case HRTIMER_CB_IRQSAFE_PERCPU: + case HRTIMER_CB_IRQSAFE_UNLOCKED: /* * This is solely for the sched tick emulation with * dynamic tick support to ensure that we do not * restart the tick right on the edge and end up with * the tick timer in the softirq ! The calling site - * takes care of this. + * takes care of this. Also used for hrtimer sleeper ! */ + debug_hrtimer_deactivate(timer); return 1; case HRTIMER_CB_IRQSAFE: case HRTIMER_CB_SOFTIRQ: @@ -735,6 +836,8 @@ static void enqueue_hrtimer(struct hrtimer *timer, struct hrtimer *entry; int leftmost = 1; + debug_hrtimer_activate(timer); + /* * Find the right place in the rbtree: */ @@ -831,6 +934,7 @@ 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, @@ -878,6 +982,7 @@ 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); @@ -896,10 +1001,18 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) */ raise = timer->state == HRTIMER_STATE_PENDING; + /* + * We use preempt_disable to prevent this task from migrating after + * setting up the softirq and raising it. Otherwise, if me migrate + * we will raise the softirq on the wrong CPU. + */ + preempt_disable(); + unlock_hrtimer_base(timer, &flags); if (raise) hrtimer_raise_softirq(); + preempt_enable(); return ret; } @@ -971,7 +1084,7 @@ ktime_t hrtimer_get_remaining(const struct hrtimer *timer) } EXPORT_SYMBOL_GPL(hrtimer_get_remaining); -#if defined(CONFIG_NO_IDLE_HZ) || defined(CONFIG_NO_HZ) +#ifdef CONFIG_NO_HZ /** * hrtimer_get_next_event - get the time until next expiry event * @@ -1011,14 +1124,8 @@ 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; @@ -1039,6 +1146,19 @@ 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); /** @@ -1072,6 +1192,7 @@ 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; @@ -1120,11 +1241,13 @@ 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); fn = timer->function; - if (timer->cb_mode == HRTIMER_CB_IRQSAFE_NO_SOFTIRQ) { + if (timer->cb_mode == HRTIMER_CB_IRQSAFE_PERCPU || + timer->cb_mode == HRTIMER_CB_IRQSAFE_UNLOCKED) { /* * Used for scheduler timers, avoid lock inversion with * rq->lock and tasklist_lock. @@ -1331,7 +1454,7 @@ void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task) sl->timer.function = hrtimer_wakeup; sl->task = task; #ifdef CONFIG_HIGH_RES_TIMERS - sl->timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ; + sl->timer.cb_mode = HRTIMER_CB_IRQSAFE_UNLOCKED; #endif } @@ -1378,22 +1501,27 @@ 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, @@ -1401,20 +1529,23 @@ 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; @@ -1423,7 +1554,10 @@ 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 @@ -1459,28 +1593,95 @@ static void __cpuinit init_hrtimers_cpu(int cpu) #ifdef CONFIG_HOTPLUG_CPU -static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, - struct hrtimer_clock_base *new_base) +static int migrate_hrtimer_list(struct hrtimer_clock_base *old_base, + struct hrtimer_clock_base *new_base, int dcpu) { struct hrtimer *timer; struct rb_node *node; + int raise = 0; while ((node = rb_first(&old_base->active))) { timer = rb_entry(node, struct hrtimer, node); BUG_ON(hrtimer_callback_running(timer)); - __remove_hrtimer(timer, old_base, HRTIMER_STATE_INACTIVE, 0); + debug_hrtimer_deactivate(timer); + + /* + * Should not happen. Per CPU timers should be + * canceled _before_ the migration code is called + */ + if (timer->cb_mode == HRTIMER_CB_IRQSAFE_PERCPU) { + __remove_hrtimer(timer, old_base, + HRTIMER_STATE_INACTIVE, 0); + WARN(1, "hrtimer (%p %p)active but cpu %d dead\n", + timer, timer->function, dcpu); + continue; + } + + /* + * Mark it as STATE_MIGRATE not INACTIVE otherwise the + * timer could be seen as !active and just vanish away + * under us on another CPU + */ + __remove_hrtimer(timer, old_base, HRTIMER_STATE_MIGRATE, 0); timer->base = new_base; /* * Enqueue the timer. Allow reprogramming of the event device */ enqueue_hrtimer(timer, new_base, 1); + +#ifdef CONFIG_HIGH_RES_TIMERS + /* + * Happens with high res enabled when the timer was + * already expired and the callback mode is + * HRTIMER_CB_IRQSAFE_UNLOCKED (hrtimer_sleeper). The + * enqueue code does not move them to the soft irq + * pending list for performance/latency reasons, but + * in the migration state, we need to do that + * otherwise we end up with a stale timer. + */ + if (timer->state == HRTIMER_STATE_MIGRATE) { + timer->state = HRTIMER_STATE_PENDING; + list_add_tail(&timer->cb_entry, + &new_base->cpu_base->cb_pending); + raise = 1; + } +#endif + /* Clear the migration state bit */ + timer->state &= ~HRTIMER_STATE_MIGRATE; + } + return raise; +} + +#ifdef CONFIG_HIGH_RES_TIMERS +static int migrate_hrtimer_pending(struct hrtimer_cpu_base *old_base, + struct hrtimer_cpu_base *new_base) +{ + struct hrtimer *timer; + int raise = 0; + + while (!list_empty(&old_base->cb_pending)) { + timer = list_entry(old_base->cb_pending.next, + struct hrtimer, cb_entry); + + __remove_hrtimer(timer, timer->base, HRTIMER_STATE_PENDING, 0); + timer->base = &new_base->clock_base[timer->base->index]; + list_add_tail(&timer->cb_entry, &new_base->cb_pending); + raise = 1; } + return raise; +} +#else +static int migrate_hrtimer_pending(struct hrtimer_cpu_base *old_base, + struct hrtimer_cpu_base *new_base) +{ + return 0; } +#endif static void migrate_hrtimers(int cpu) { struct hrtimer_cpu_base *old_base, *new_base; - int i; + int i, raise = 0; BUG_ON(cpu_online(cpu)); old_base = &per_cpu(hrtimer_bases, cpu); @@ -1493,14 +1694,21 @@ static void migrate_hrtimers(int cpu) spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING); for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { - migrate_hrtimer_list(&old_base->clock_base[i], - &new_base->clock_base[i]); + if (migrate_hrtimer_list(&old_base->clock_base[i], + &new_base->clock_base[i], cpu)) + raise = 1; } + if (migrate_hrtimer_pending(old_base, new_base)) + raise = 1; + spin_unlock(&old_base->lock); spin_unlock(&new_base->lock); local_irq_enable(); put_cpu_var(hrtimer_bases); + + if (raise) + hrtimer_raise_softirq(); } #endif /* CONFIG_HOTPLUG_CPU */ @@ -1541,7 +1749,7 @@ void __init hrtimers_init(void) (void *)(long)smp_processor_id()); register_cpu_notifier(&hrtimers_nb); #ifdef CONFIG_HIGH_RES_TIMERS - open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq, NULL); + open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq); #endif }