X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Ftimer.c;h=15533b792397be532ddcce7f2d24c04f78efba75;hb=285caad415f459f336247932b4db95a571357a02;hp=6d843e100e75d9c6ce2ccb269bf7c4dd6839e32f;hpb=fd064b9b7770d5c7705bf9542950c7bd81c30f98;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/timer.c b/kernel/timer.c index 6d843e1..15533b7 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1,7 +1,7 @@ /* * linux/kernel/timer.c * - * Kernel internal timers, kernel timekeeping, basic process system calls + * Kernel internal timers, basic process system calls * * Copyright (C) 1991, 1992 Linus Torvalds * @@ -26,6 +26,7 @@ #include #include #include +#include #include #include #include @@ -34,6 +35,10 @@ #include #include #include +#include +#include +#include +#include #include #include @@ -41,6 +46,9 @@ #include #include +#define CREATE_TRACE_POINTS +#include + u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES; EXPORT_SYMBOL(jiffies_64); @@ -55,52 +63,63 @@ EXPORT_SYMBOL(jiffies_64); #define TVN_MASK (TVN_SIZE - 1) #define TVR_MASK (TVR_SIZE - 1) -typedef struct tvec_s { +struct tvec { struct list_head vec[TVN_SIZE]; -} tvec_t; +}; -typedef struct tvec_root_s { +struct tvec_root { struct list_head vec[TVR_SIZE]; -} tvec_root_t; +}; -struct tvec_t_base_s { +struct tvec_base { spinlock_t lock; struct timer_list *running_timer; unsigned long timer_jiffies; - tvec_root_t tv1; - tvec_t tv2; - tvec_t tv3; - tvec_t tv4; - tvec_t tv5; -} ____cacheline_aligned_in_smp; - -typedef struct tvec_t_base_s tvec_base_t; - -tvec_base_t boot_tvec_bases; + unsigned long next_timer; + struct tvec_root tv1; + struct tvec tv2; + struct tvec tv3; + struct tvec tv4; + struct tvec tv5; +} ____cacheline_aligned; + +struct tvec_base boot_tvec_bases; EXPORT_SYMBOL(boot_tvec_bases); -static DEFINE_PER_CPU(tvec_base_t *, tvec_bases) = &boot_tvec_bases; +static DEFINE_PER_CPU(struct tvec_base *, tvec_bases) = &boot_tvec_bases; -/** - * __round_jiffies - function to round jiffies to a full second - * @j: the time in (absolute) jiffies that should be rounded - * @cpu: the processor number on which the timeout will happen - * - * __round_jiffies() rounds an absolute time in the future (in jiffies) - * up or down to (approximately) full seconds. This is useful for timers - * for which the exact time they fire does not matter too much, as long as - * they fire approximately every X seconds. - * - * By rounding these timers to whole seconds, all such timers will fire - * at the same time, rather than at various times spread out. The goal - * of this is to have the CPU wake up less, which saves power. - * - * The exact rounding is skewed for each processor to avoid all - * processors firing at the exact same time, which could lead - * to lock contention or spurious cache line bouncing. - * - * The return value is the rounded version of the @j parameter. +/* + * Note that all tvec_bases are 2 byte aligned and lower bit of + * base in timer_list is guaranteed to be zero. Use the LSB for + * the new flag to indicate whether the timer is deferrable */ -unsigned long __round_jiffies(unsigned long j, int cpu) +#define TBASE_DEFERRABLE_FLAG (0x1) + +/* Functions below help us manage 'deferrable' flag */ +static inline unsigned int tbase_get_deferrable(struct tvec_base *base) +{ + return ((unsigned int)(unsigned long)base & TBASE_DEFERRABLE_FLAG); +} + +static inline struct tvec_base *tbase_get_base(struct tvec_base *base) +{ + return ((struct tvec_base *)((unsigned long)base & ~TBASE_DEFERRABLE_FLAG)); +} + +static inline void timer_set_deferrable(struct timer_list *timer) +{ + timer->base = ((struct tvec_base *)((unsigned long)(timer->base) | + TBASE_DEFERRABLE_FLAG)); +} + +static inline void +timer_set_base(struct timer_list *timer, struct tvec_base *new_base) +{ + timer->base = (struct tvec_base *)((unsigned long)(new_base) | + tbase_get_deferrable(timer->base)); +} + +static unsigned long round_jiffies_common(unsigned long j, int cpu, + bool force_up) { int rem; unsigned long original = j; @@ -122,8 +141,9 @@ unsigned long __round_jiffies(unsigned long j, int cpu) * due to delays of the timer irq, long irq off times etc etc) then * we should round down to the whole second, not up. Use 1/4th second * as cutoff for this rounding as an extreme upper bound for this. + * But never round down if @force_up is set. */ - if (rem < HZ/4) /* round down */ + if (rem < HZ/4 && !force_up) /* round down */ j = j - rem; else /* round up */ j = j - rem + HZ; @@ -135,6 +155,31 @@ unsigned long __round_jiffies(unsigned long j, int cpu) return original; return j; } + +/** + * __round_jiffies - function to round jiffies to a full second + * @j: the time in (absolute) jiffies that should be rounded + * @cpu: the processor number on which the timeout will happen + * + * __round_jiffies() rounds an absolute time in the future (in jiffies) + * up or down to (approximately) full seconds. This is useful for timers + * for which the exact time they fire does not matter too much, as long as + * they fire approximately every X seconds. + * + * By rounding these timers to whole seconds, all such timers will fire + * at the same time, rather than at various times spread out. The goal + * of this is to have the CPU wake up less, which saves power. + * + * The exact rounding is skewed for each processor to avoid all + * processors firing at the exact same time, which could lead + * to lock contention or spurious cache line bouncing. + * + * The return value is the rounded version of the @j parameter. + */ +unsigned long __round_jiffies(unsigned long j, int cpu) +{ + return round_jiffies_common(j, cpu, false); +} EXPORT_SYMBOL_GPL(__round_jiffies); /** @@ -159,13 +204,10 @@ EXPORT_SYMBOL_GPL(__round_jiffies); */ unsigned long __round_jiffies_relative(unsigned long j, int cpu) { - /* - * In theory the following code can skip a jiffy in case jiffies - * increments right between the addition and the later subtraction. - * However since the entire point of this function is to use approximate - * timeouts, it's entirely ok to not handle that. - */ - return __round_jiffies(j + jiffies, cpu) - jiffies; + unsigned long j0 = jiffies; + + /* Use j0 because jiffies might change while we run */ + return round_jiffies_common(j + j0, cpu, false) - j0; } EXPORT_SYMBOL_GPL(__round_jiffies_relative); @@ -186,7 +228,7 @@ EXPORT_SYMBOL_GPL(__round_jiffies_relative); */ unsigned long round_jiffies(unsigned long j) { - return __round_jiffies(j, raw_smp_processor_id()); + return round_jiffies_common(j, raw_smp_processor_id(), false); } EXPORT_SYMBOL_GPL(round_jiffies); @@ -211,8 +253,73 @@ unsigned long round_jiffies_relative(unsigned long j) } EXPORT_SYMBOL_GPL(round_jiffies_relative); +/** + * __round_jiffies_up - function to round jiffies up to a full second + * @j: the time in (absolute) jiffies that should be rounded + * @cpu: the processor number on which the timeout will happen + * + * This is the same as __round_jiffies() except that it will never + * round down. This is useful for timeouts for which the exact time + * of firing does not matter too much, as long as they don't fire too + * early. + */ +unsigned long __round_jiffies_up(unsigned long j, int cpu) +{ + return round_jiffies_common(j, cpu, true); +} +EXPORT_SYMBOL_GPL(__round_jiffies_up); -static inline void set_running_timer(tvec_base_t *base, +/** + * __round_jiffies_up_relative - function to round jiffies up to a full second + * @j: the time in (relative) jiffies that should be rounded + * @cpu: the processor number on which the timeout will happen + * + * This is the same as __round_jiffies_relative() except that it will never + * round down. This is useful for timeouts for which the exact time + * of firing does not matter too much, as long as they don't fire too + * early. + */ +unsigned long __round_jiffies_up_relative(unsigned long j, int cpu) +{ + unsigned long j0 = jiffies; + + /* Use j0 because jiffies might change while we run */ + return round_jiffies_common(j + j0, cpu, true) - j0; +} +EXPORT_SYMBOL_GPL(__round_jiffies_up_relative); + +/** + * round_jiffies_up - function to round jiffies up to a full second + * @j: the time in (absolute) jiffies that should be rounded + * + * This is the same as round_jiffies() except that it will never + * round down. This is useful for timeouts for which the exact time + * of firing does not matter too much, as long as they don't fire too + * early. + */ +unsigned long round_jiffies_up(unsigned long j) +{ + return round_jiffies_common(j, raw_smp_processor_id(), true); +} +EXPORT_SYMBOL_GPL(round_jiffies_up); + +/** + * round_jiffies_up_relative - function to round jiffies up to a full second + * @j: the time in (relative) jiffies that should be rounded + * + * This is the same as round_jiffies_relative() except that it will never + * round down. This is useful for timeouts for which the exact time + * of firing does not matter too much, as long as they don't fire too + * early. + */ +unsigned long round_jiffies_up_relative(unsigned long j) +{ + return __round_jiffies_up_relative(j, raw_smp_processor_id()); +} +EXPORT_SYMBOL_GPL(round_jiffies_up_relative); + + +static inline void set_running_timer(struct tvec_base *base, struct timer_list *timer) { #ifdef CONFIG_SMP @@ -220,7 +327,7 @@ static inline void set_running_timer(tvec_base_t *base, #endif } -static void internal_add_timer(tvec_base_t *base, struct timer_list *timer) +static void internal_add_timer(struct tvec_base *base, struct timer_list *timer) { unsigned long expires = timer->expires; unsigned long idx = expires - base->timer_jiffies; @@ -262,25 +369,229 @@ static void internal_add_timer(tvec_base_t *base, struct timer_list *timer) list_add_tail(&timer->entry, vec); } +#ifdef CONFIG_TIMER_STATS +void __timer_stats_timer_set_start_info(struct timer_list *timer, void *addr) +{ + if (timer->start_site) + return; + + timer->start_site = addr; + memcpy(timer->start_comm, current->comm, TASK_COMM_LEN); + timer->start_pid = current->pid; +} + +static void timer_stats_account_timer(struct timer_list *timer) +{ + unsigned int flag = 0; + + if (likely(!timer->start_site)) + return; + if (unlikely(tbase_get_deferrable(timer->base))) + flag |= TIMER_STATS_FLAG_DEFERRABLE; + + timer_stats_update_stats(timer, timer->start_pid, timer->start_site, + timer->function, timer->start_comm, flag); +} + +#else +static void timer_stats_account_timer(struct timer_list *timer) {} +#endif + +#ifdef CONFIG_DEBUG_OBJECTS_TIMERS + +static struct debug_obj_descr timer_debug_descr; + +/* + * fixup_init is called when: + * - an active object is initialized + */ +static int timer_fixup_init(void *addr, enum debug_obj_state state) +{ + struct timer_list *timer = addr; + + switch (state) { + case ODEBUG_STATE_ACTIVE: + del_timer_sync(timer); + debug_object_init(timer, &timer_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 timer_fixup_activate(void *addr, enum debug_obj_state state) +{ + struct timer_list *timer = addr; + + switch (state) { + + case ODEBUG_STATE_NOTAVAILABLE: + /* + * This is not really a fixup. The timer was + * statically initialized. We just make sure that it + * is tracked in the object tracker. + */ + if (timer->entry.next == NULL && + timer->entry.prev == TIMER_ENTRY_STATIC) { + debug_object_init(timer, &timer_debug_descr); + debug_object_activate(timer, &timer_debug_descr); + return 0; + } else { + 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 timer_fixup_free(void *addr, enum debug_obj_state state) +{ + struct timer_list *timer = addr; + + switch (state) { + case ODEBUG_STATE_ACTIVE: + del_timer_sync(timer); + debug_object_free(timer, &timer_debug_descr); + return 1; + default: + return 0; + } +} + +static struct debug_obj_descr timer_debug_descr = { + .name = "timer_list", + .fixup_init = timer_fixup_init, + .fixup_activate = timer_fixup_activate, + .fixup_free = timer_fixup_free, +}; + +static inline void debug_timer_init(struct timer_list *timer) +{ + debug_object_init(timer, &timer_debug_descr); +} + +static inline void debug_timer_activate(struct timer_list *timer) +{ + debug_object_activate(timer, &timer_debug_descr); +} + +static inline void debug_timer_deactivate(struct timer_list *timer) +{ + debug_object_deactivate(timer, &timer_debug_descr); +} + +static inline void debug_timer_free(struct timer_list *timer) +{ + debug_object_free(timer, &timer_debug_descr); +} + +static void __init_timer(struct timer_list *timer, + const char *name, + struct lock_class_key *key); + +void init_timer_on_stack_key(struct timer_list *timer, + const char *name, + struct lock_class_key *key) +{ + debug_object_init_on_stack(timer, &timer_debug_descr); + __init_timer(timer, name, key); +} +EXPORT_SYMBOL_GPL(init_timer_on_stack_key); + +void destroy_timer_on_stack(struct timer_list *timer) +{ + debug_object_free(timer, &timer_debug_descr); +} +EXPORT_SYMBOL_GPL(destroy_timer_on_stack); + +#else +static inline void debug_timer_init(struct timer_list *timer) { } +static inline void debug_timer_activate(struct timer_list *timer) { } +static inline void debug_timer_deactivate(struct timer_list *timer) { } +#endif + +static inline void debug_init(struct timer_list *timer) +{ + debug_timer_init(timer); + trace_timer_init(timer); +} + +static inline void +debug_activate(struct timer_list *timer, unsigned long expires) +{ + debug_timer_activate(timer); + trace_timer_start(timer, expires); +} + +static inline void debug_deactivate(struct timer_list *timer) +{ + debug_timer_deactivate(timer); + trace_timer_cancel(timer); +} + +static void __init_timer(struct timer_list *timer, + const char *name, + struct lock_class_key *key) +{ + timer->entry.next = NULL; + timer->base = __raw_get_cpu_var(tvec_bases); +#ifdef CONFIG_TIMER_STATS + timer->start_site = NULL; + timer->start_pid = -1; + memset(timer->start_comm, 0, TASK_COMM_LEN); +#endif + lockdep_init_map(&timer->lockdep_map, name, key, 0); +} + /** - * init_timer - initialize a timer. + * init_timer_key - initialize a timer * @timer: the timer to be initialized + * @name: name of the timer + * @key: lockdep class key of the fake lock used for tracking timer + * sync lock dependencies * - * init_timer() must be done to a timer prior calling *any* of the + * init_timer_key() must be done to a timer prior calling *any* of the * other timer functions. */ -void fastcall init_timer(struct timer_list *timer) +void init_timer_key(struct timer_list *timer, + const char *name, + struct lock_class_key *key) { - timer->entry.next = NULL; - timer->base = __raw_get_cpu_var(tvec_bases); + debug_init(timer); + __init_timer(timer, name, key); +} +EXPORT_SYMBOL(init_timer_key); + +void init_timer_deferrable_key(struct timer_list *timer, + const char *name, + struct lock_class_key *key) +{ + init_timer_key(timer, name, key); + timer_set_deferrable(timer); } -EXPORT_SYMBOL(init_timer); +EXPORT_SYMBOL(init_timer_deferrable_key); static inline void detach_timer(struct timer_list *timer, - int clear_pending) + int clear_pending) { struct list_head *entry = &timer->entry; + debug_deactivate(timer); + __list_del(entry->prev, entry->next); if (clear_pending) entry->next = NULL; @@ -299,17 +610,18 @@ static inline void detach_timer(struct timer_list *timer, * possible to set timer->base = NULL and drop the lock: the timer remains * locked. */ -static tvec_base_t *lock_timer_base(struct timer_list *timer, +static struct tvec_base *lock_timer_base(struct timer_list *timer, unsigned long *flags) __acquires(timer->base->lock) { - tvec_base_t *base; + struct tvec_base *base; for (;;) { - base = timer->base; + struct tvec_base *prelock_base = timer->base; + base = tbase_get_base(prelock_base); if (likely(base != NULL)) { spin_lock_irqsave(&base->lock, *flags); - if (likely(base == timer->base)) + if (likely(prelock_base == timer->base)) return base; /* The timer has migrated to another CPU */ spin_unlock_irqrestore(&base->lock, *flags); @@ -318,22 +630,43 @@ static tvec_base_t *lock_timer_base(struct timer_list *timer, } } -int __mod_timer(struct timer_list *timer, unsigned long expires) +static inline int +__mod_timer(struct timer_list *timer, unsigned long expires, + bool pending_only, int pinned) { - tvec_base_t *base, *new_base; + struct tvec_base *base, *new_base; unsigned long flags; - int ret = 0; + int ret = 0 , cpu; + timer_stats_timer_set_start_info(timer); BUG_ON(!timer->function); base = lock_timer_base(timer, &flags); if (timer_pending(timer)) { detach_timer(timer, 0); + if (timer->expires == base->next_timer && + !tbase_get_deferrable(timer->base)) + base->next_timer = base->timer_jiffies; ret = 1; + } else { + if (pending_only) + goto out_unlock; } - new_base = __get_cpu_var(tvec_bases); + debug_activate(timer, expires); + + cpu = smp_processor_id(); + +#if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP) + if (!pinned && get_sysctl_timer_migration() && idle_cpu(cpu)) { + int preferred_cpu = get_nohz_load_balancer(); + + if (preferred_cpu >= 0) + cpu = preferred_cpu; + } +#endif + new_base = per_cpu(tvec_bases, cpu); if (base != new_base) { /* @@ -345,42 +678,41 @@ int __mod_timer(struct timer_list *timer, unsigned long expires) */ if (likely(base->running_timer != timer)) { /* See the comment in lock_timer_base() */ - timer->base = NULL; + timer_set_base(timer, NULL); spin_unlock(&base->lock); base = new_base; spin_lock(&base->lock); - timer->base = base; + timer_set_base(timer, base); } } timer->expires = expires; + if (time_before(timer->expires, base->next_timer) && + !tbase_get_deferrable(timer->base)) + base->next_timer = timer->expires; internal_add_timer(base, timer); + +out_unlock: spin_unlock_irqrestore(&base->lock, flags); return ret; } -EXPORT_SYMBOL(__mod_timer); - /** - * add_timer_on - start a timer on a particular CPU - * @timer: the timer to be added - * @cpu: the CPU to start it on + * mod_timer_pending - modify a pending timer's timeout + * @timer: the pending timer to be modified + * @expires: new timeout in jiffies * - * This is not very scalable on SMP. Double adds are not possible. + * mod_timer_pending() is the same for pending timers as mod_timer(), + * but will not re-activate and modify already deleted timers. + * + * It is useful for unserialized use of timers. */ -void add_timer_on(struct timer_list *timer, int cpu) +int mod_timer_pending(struct timer_list *timer, unsigned long expires) { - tvec_base_t *base = per_cpu(tvec_bases, cpu); - unsigned long flags; - - BUG_ON(timer_pending(timer) || !timer->function); - spin_lock_irqsave(&base->lock, flags); - timer->base = base; - internal_add_timer(base, timer); - spin_unlock_irqrestore(&base->lock, flags); + return __mod_timer(timer, expires, true, TIMER_NOT_PINNED); } - +EXPORT_SYMBOL(mod_timer_pending); /** * mod_timer - modify a timer's timeout @@ -404,20 +736,94 @@ void add_timer_on(struct timer_list *timer, int cpu) */ int mod_timer(struct timer_list *timer, unsigned long expires) { - BUG_ON(!timer->function); - /* * This is a common optimization triggered by the * networking code - if the timer is re-modified * to be the same thing then just return: */ + if (timer_pending(timer) && timer->expires == expires) + return 1; + + return __mod_timer(timer, expires, false, TIMER_NOT_PINNED); +} +EXPORT_SYMBOL(mod_timer); + +/** + * mod_timer_pinned - modify a timer's timeout + * @timer: the timer to be modified + * @expires: new timeout in jiffies + * + * mod_timer_pinned() is a way to update the expire field of an + * active timer (if the timer is inactive it will be activated) + * and not allow the timer to be migrated to a different CPU. + * + * mod_timer_pinned(timer, expires) is equivalent to: + * + * del_timer(timer); timer->expires = expires; add_timer(timer); + */ +int mod_timer_pinned(struct timer_list *timer, unsigned long expires) +{ if (timer->expires == expires && timer_pending(timer)) return 1; - return __mod_timer(timer, expires); + return __mod_timer(timer, expires, false, TIMER_PINNED); } +EXPORT_SYMBOL(mod_timer_pinned); -EXPORT_SYMBOL(mod_timer); +/** + * add_timer - start a timer + * @timer: the timer to be added + * + * The kernel will do a ->function(->data) callback from the + * timer interrupt at the ->expires point in the future. The + * current time is 'jiffies'. + * + * The timer's ->expires, ->function (and if the handler uses it, ->data) + * fields must be set prior calling this function. + * + * Timers with an ->expires field in the past will be executed in the next + * timer tick. + */ +void add_timer(struct timer_list *timer) +{ + BUG_ON(timer_pending(timer)); + mod_timer(timer, timer->expires); +} +EXPORT_SYMBOL(add_timer); + +/** + * add_timer_on - start a timer on a particular CPU + * @timer: the timer to be added + * @cpu: the CPU to start it on + * + * This is not very scalable on SMP. Double adds are not possible. + */ +void add_timer_on(struct timer_list *timer, int cpu) +{ + struct tvec_base *base = per_cpu(tvec_bases, cpu); + unsigned long flags; + + timer_stats_timer_set_start_info(timer); + BUG_ON(timer_pending(timer) || !timer->function); + spin_lock_irqsave(&base->lock, flags); + timer_set_base(timer, base); + debug_activate(timer, timer->expires); + if (time_before(timer->expires, base->next_timer) && + !tbase_get_deferrable(timer->base)) + base->next_timer = timer->expires; + internal_add_timer(base, timer); + /* + * Check whether the other CPU is idle and needs to be + * triggered to reevaluate the timer wheel when nohz is + * active. We are protected against the other CPU fiddling + * with the timer by holding the timer base lock. This also + * makes sure that a CPU on the way to idle can not evaluate + * the timer wheel. + */ + wake_up_idle_cpu(cpu); + spin_unlock_irqrestore(&base->lock, flags); +} +EXPORT_SYMBOL_GPL(add_timer_on); /** * del_timer - deactive a timer. @@ -432,14 +838,18 @@ EXPORT_SYMBOL(mod_timer); */ int del_timer(struct timer_list *timer) { - tvec_base_t *base; + struct tvec_base *base; unsigned long flags; int ret = 0; + timer_stats_timer_clear_start_info(timer); if (timer_pending(timer)) { base = lock_timer_base(timer, &flags); if (timer_pending(timer)) { detach_timer(timer, 1); + if (timer->expires == base->next_timer && + !tbase_get_deferrable(timer->base)) + base->next_timer = base->timer_jiffies; ret = 1; } spin_unlock_irqrestore(&base->lock, flags); @@ -447,7 +857,6 @@ int del_timer(struct timer_list *timer) return ret; } - EXPORT_SYMBOL(del_timer); #ifdef CONFIG_SMP @@ -462,7 +871,7 @@ EXPORT_SYMBOL(del_timer); */ int try_to_del_timer_sync(struct timer_list *timer) { - tvec_base_t *base; + struct tvec_base *base; unsigned long flags; int ret = -1; @@ -474,6 +883,9 @@ int try_to_del_timer_sync(struct timer_list *timer) ret = 0; if (timer_pending(timer)) { detach_timer(timer, 1); + if (timer->expires == base->next_timer && + !tbase_get_deferrable(timer->base)) + base->next_timer = base->timer_jiffies; ret = 1; } out: @@ -481,6 +893,7 @@ out: return ret; } +EXPORT_SYMBOL(try_to_del_timer_sync); /** * del_timer_sync - deactivate a timer and wait for the handler to finish. @@ -501,6 +914,15 @@ out: */ int del_timer_sync(struct timer_list *timer) { +#ifdef CONFIG_LOCKDEP + unsigned long flags; + + local_irq_save(flags); + lock_map_acquire(&timer->lockdep_map); + lock_map_release(&timer->lockdep_map); + local_irq_restore(flags); +#endif + for (;;) { int ret = try_to_del_timer_sync(timer); if (ret >= 0) @@ -508,11 +930,10 @@ int del_timer_sync(struct timer_list *timer) cpu_relax(); } } - EXPORT_SYMBOL(del_timer_sync); #endif -static int cascade(tvec_base_t *base, tvec_t *tv, int index) +static int cascade(struct tvec_base *base, struct tvec *tv, int index) { /* cascade all the timers from tv up one level */ struct timer_list *timer, *tmp; @@ -525,7 +946,7 @@ static int cascade(tvec_base_t *base, tvec_t *tv, int index) * don't have to detach them individually. */ list_for_each_entry_safe(timer, tmp, &tv_list, entry) { - BUG_ON(timer->base != base); + BUG_ON(tbase_get_base(timer->base) != base); internal_add_timer(base, timer); } @@ -541,7 +962,7 @@ static int cascade(tvec_base_t *base, tvec_t *tv, int index) * This function cascades all vectors and executes all expired timer * vectors. */ -static inline void __run_timers(tvec_base_t *base) +static inline void __run_timers(struct tvec_base *base) { struct timer_list *timer; @@ -549,7 +970,7 @@ static inline void __run_timers(tvec_base_t *base) while (time_after_eq(jiffies, base->timer_jiffies)) { struct list_head work_list; struct list_head *head = &work_list; - int index = base->timer_jiffies & TVR_MASK; + int index = base->timer_jiffies & TVR_MASK; /* * Cascade timers: @@ -565,592 +986,206 @@ static inline void __run_timers(tvec_base_t *base) void (*fn)(unsigned long); unsigned long data; - timer = list_entry(head->next,struct timer_list,entry); - fn = timer->function; - data = timer->data; - - set_running_timer(base, timer); - detach_timer(timer, 1); - spin_unlock_irq(&base->lock); - { - int preempt_count = preempt_count(); - fn(data); - if (preempt_count != preempt_count()) { - printk(KERN_WARNING "huh, entered %p " - "with preempt_count %08x, exited" - " with %08x?\n", - fn, preempt_count, - preempt_count()); - BUG(); - } - } - spin_lock_irq(&base->lock); - } - } - set_running_timer(base, NULL); - spin_unlock_irq(&base->lock); -} - -#if defined(CONFIG_NO_IDLE_HZ) || defined(CONFIG_NO_HZ) -/* - * Find out when the next timer event is due to happen. This - * is used on S/390 to stop all activity when a cpus is idle. - * This functions needs to be called disabled. - */ -static unsigned long __next_timer_interrupt(tvec_base_t *base) -{ - unsigned long timer_jiffies = base->timer_jiffies; - unsigned long expires = timer_jiffies + (LONG_MAX >> 1); - int index, slot, array, found = 0; - struct timer_list *nte; - tvec_t *varray[4]; - - /* Look for timer events in tv1. */ - index = slot = timer_jiffies & TVR_MASK; - do { - list_for_each_entry(nte, base->tv1.vec + slot, entry) { - found = 1; - expires = nte->expires; - /* Look at the cascade bucket(s)? */ - if (!index || slot < index) - goto cascade; - return expires; - } - slot = (slot + 1) & TVR_MASK; - } while (slot != index); - -cascade: - /* Calculate the next cascade event */ - if (index) - timer_jiffies += TVR_SIZE - index; - timer_jiffies >>= TVR_BITS; - - /* Check tv2-tv5. */ - varray[0] = &base->tv2; - varray[1] = &base->tv3; - varray[2] = &base->tv4; - varray[3] = &base->tv5; - - for (array = 0; array < 4; array++) { - tvec_t *varp = varray[array]; - - index = slot = timer_jiffies & TVN_MASK; - do { - list_for_each_entry(nte, varp->vec + slot, entry) { - found = 1; - if (time_before(nte->expires, expires)) - expires = nte->expires; - } - /* - * Do we still search for the first timer or are - * we looking up the cascade buckets ? - */ - if (found) { - /* Look at the cascade bucket(s)? */ - if (!index || slot < index) - break; - return expires; - } - slot = (slot + 1) & TVN_MASK; - } while (slot != index); - - if (index) - timer_jiffies += TVN_SIZE - index; - timer_jiffies >>= TVN_BITS; - } - return expires; -} - -/* - * Check, if the next hrtimer event is before the next timer wheel - * event: - */ -static unsigned long cmp_next_hrtimer_event(unsigned long now, - unsigned long expires) -{ - ktime_t hr_delta = hrtimer_get_next_event(); - struct timespec tsdelta; - - if (hr_delta.tv64 == KTIME_MAX) - return expires; - - if (hr_delta.tv64 <= TICK_NSEC) - return now; - - tsdelta = ktime_to_timespec(hr_delta); - now += timespec_to_jiffies(&tsdelta); - if (time_before(now, expires)) - return now; - return expires; -} - -/** - * next_timer_interrupt - return the jiffy of the next pending timer - */ -unsigned long get_next_timer_interrupt(unsigned long now) -{ - tvec_base_t *base = __get_cpu_var(tvec_bases); - unsigned long expires; - - spin_lock(&base->lock); - expires = __next_timer_interrupt(base); - spin_unlock(&base->lock); - - if (time_before_eq(expires, now)) - return now; - - return cmp_next_hrtimer_event(now, expires); -} - -#ifdef CONFIG_NO_IDLE_HZ -unsigned long next_timer_interrupt(void) -{ - return get_next_timer_interrupt(jiffies); -} -#endif - -#endif - -/******************************************************************/ - -/* - * The current time - * wall_to_monotonic is what we need to add to xtime (or xtime corrected - * for sub jiffie times) to get to monotonic time. Monotonic is pegged - * at zero at system boot time, so wall_to_monotonic will be negative, - * however, we will ALWAYS keep the tv_nsec part positive so we can use - * the usual normalization. - */ -struct timespec xtime __attribute__ ((aligned (16))); -struct timespec wall_to_monotonic __attribute__ ((aligned (16))); - -EXPORT_SYMBOL(xtime); - - -/* XXX - all of this timekeeping code should be later moved to time.c */ -#include -static struct clocksource *clock; /* pointer to current clocksource */ - -#ifdef CONFIG_GENERIC_TIME -/** - * __get_nsec_offset - Returns nanoseconds since last call to periodic_hook - * - * private function, must hold xtime_lock lock when being - * called. Returns the number of nanoseconds since the - * last call to update_wall_time() (adjusted by NTP scaling) - */ -static inline s64 __get_nsec_offset(void) -{ - cycle_t cycle_now, cycle_delta; - s64 ns_offset; - - /* read clocksource: */ - cycle_now = clocksource_read(clock); - - /* calculate the delta since the last update_wall_time: */ - cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; - - /* convert to nanoseconds: */ - ns_offset = cyc2ns(clock, cycle_delta); - - return ns_offset; -} - -/** - * __get_realtime_clock_ts - Returns the time of day in a timespec - * @ts: pointer to the timespec to be set - * - * Returns the time of day in a timespec. Used by - * do_gettimeofday() and get_realtime_clock_ts(). - */ -static inline void __get_realtime_clock_ts(struct timespec *ts) -{ - unsigned long seq; - s64 nsecs; - - do { - seq = read_seqbegin(&xtime_lock); - - *ts = xtime; - nsecs = __get_nsec_offset(); - - } while (read_seqretry(&xtime_lock, seq)); - - timespec_add_ns(ts, nsecs); -} - -/** - * getnstimeofday - Returns the time of day in a timespec - * @ts: pointer to the timespec to be set - * - * Returns the time of day in a timespec. - */ -void getnstimeofday(struct timespec *ts) -{ - __get_realtime_clock_ts(ts); -} - -EXPORT_SYMBOL(getnstimeofday); - -/** - * do_gettimeofday - Returns the time of day in a timeval - * @tv: pointer to the timeval to be set - * - * NOTE: Users should be converted to using get_realtime_clock_ts() - */ -void do_gettimeofday(struct timeval *tv) -{ - struct timespec now; - - __get_realtime_clock_ts(&now); - tv->tv_sec = now.tv_sec; - tv->tv_usec = now.tv_nsec/1000; -} - -EXPORT_SYMBOL(do_gettimeofday); -/** - * do_settimeofday - Sets the time of day - * @tv: pointer to the timespec variable containing the new time - * - * Sets the time of day to the new time and update NTP and notify hrtimers - */ -int do_settimeofday(struct timespec *tv) -{ - unsigned long flags; - time_t wtm_sec, sec = tv->tv_sec; - long wtm_nsec, nsec = tv->tv_nsec; - - if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) - return -EINVAL; - - write_seqlock_irqsave(&xtime_lock, flags); - - nsec -= __get_nsec_offset(); - - wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); - wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); - - set_normalized_timespec(&xtime, sec, nsec); - set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); - - clock->error = 0; - ntp_clear(); - - write_sequnlock_irqrestore(&xtime_lock, flags); - - /* signal hrtimers about time change */ - clock_was_set(); - - return 0; -} - -EXPORT_SYMBOL(do_settimeofday); - -/** - * change_clocksource - Swaps clocksources if a new one is available - * - * Accumulates current time interval and initializes new clocksource - */ -static void change_clocksource(void) -{ - struct clocksource *new; - cycle_t now; - u64 nsec; - - new = clocksource_get_next(); - - if (clock == new) - return; - - now = clocksource_read(new); - nsec = __get_nsec_offset(); - timespec_add_ns(&xtime, nsec); - - clock = new; - clock->cycle_last = now; - - clock->error = 0; - clock->xtime_nsec = 0; - clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH); - - printk(KERN_INFO "Time: %s clocksource has been installed.\n", - clock->name); -} -#else -static inline void change_clocksource(void) { } -#endif - -/** - * timeofday_is_continuous - check to see if timekeeping is free running - */ -int timekeeping_is_continuous(void) -{ - unsigned long seq; - int ret; - - do { - seq = read_seqbegin(&xtime_lock); - - ret = clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; - - } while (read_seqretry(&xtime_lock, seq)); - - return ret; -} - -/** - * read_persistent_clock - Return time in seconds from the persistent clock. - * - * Weak dummy function for arches that do not yet support it. - * Returns seconds from epoch using the battery backed persistent clock. - * Returns zero if unsupported. - * - * XXX - Do be sure to remove it once all arches implement it. - */ -unsigned long __attribute__((weak)) read_persistent_clock(void) -{ - return 0; -} - -/* - * timekeeping_init - Initializes the clocksource and common timekeeping values - */ -void __init timekeeping_init(void) -{ - unsigned long flags; - unsigned long sec = read_persistent_clock(); - - write_seqlock_irqsave(&xtime_lock, flags); + timer = list_first_entry(head, struct timer_list,entry); + fn = timer->function; + data = timer->data; - ntp_clear(); + timer_stats_account_timer(timer); - clock = clocksource_get_next(); - clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH); - clock->cycle_last = clocksource_read(clock); + set_running_timer(base, timer); + detach_timer(timer, 1); - xtime.tv_sec = sec; - xtime.tv_nsec = 0; - set_normalized_timespec(&wall_to_monotonic, - -xtime.tv_sec, -xtime.tv_nsec); + spin_unlock_irq(&base->lock); + { + int preempt_count = preempt_count(); - write_sequnlock_irqrestore(&xtime_lock, flags); -} +#ifdef CONFIG_LOCKDEP + /* + * It is permissible to free the timer from + * inside the function that is called from + * it, this we need to take into account for + * lockdep too. To avoid bogus "held lock + * freed" warnings as well as problems when + * looking into timer->lockdep_map, make a + * copy and use that here. + */ + struct lockdep_map lockdep_map = + timer->lockdep_map; +#endif + /* + * Couple the lock chain with the lock chain at + * del_timer_sync() by acquiring the lock_map + * around the fn() call here and in + * del_timer_sync(). + */ + lock_map_acquire(&lockdep_map); + + trace_timer_expire_entry(timer); + fn(data); + trace_timer_expire_exit(timer); + lock_map_release(&lockdep_map); -/* flag for if timekeeping is suspended */ -static int timekeeping_suspended; -/* time in seconds when suspend began */ -static unsigned long timekeeping_suspend_time; + if (preempt_count != preempt_count()) { + printk(KERN_ERR "huh, entered %p " + "with preempt_count %08x, exited" + " with %08x?\n", + fn, preempt_count, + preempt_count()); + BUG(); + } + } + spin_lock_irq(&base->lock); + } + } + set_running_timer(base, NULL); + spin_unlock_irq(&base->lock); +} -/** - * timekeeping_resume - Resumes the generic timekeeping subsystem. - * @dev: unused - * - * This is for the generic clocksource timekeeping. - * xtime/wall_to_monotonic/jiffies/etc are - * still managed by arch specific suspend/resume code. +#ifdef CONFIG_NO_HZ +/* + * Find out when the next timer event is due to happen. This + * is used on S/390 to stop all activity when a CPU is idle. + * This function needs to be called with interrupts disabled. */ -static int timekeeping_resume(struct sys_device *dev) +static unsigned long __next_timer_interrupt(struct tvec_base *base) { - unsigned long flags; - unsigned long now = read_persistent_clock(); - - write_seqlock_irqsave(&xtime_lock, flags); - - if (now && (now > timekeeping_suspend_time)) { - unsigned long sleep_length = now - timekeeping_suspend_time; + unsigned long timer_jiffies = base->timer_jiffies; + unsigned long expires = timer_jiffies + NEXT_TIMER_MAX_DELTA; + int index, slot, array, found = 0; + struct timer_list *nte; + struct tvec *varray[4]; - xtime.tv_sec += sleep_length; - wall_to_monotonic.tv_sec -= sleep_length; - } - /* re-base the last cycle value */ - clock->cycle_last = clocksource_read(clock); - clock->error = 0; - timekeeping_suspended = 0; - write_sequnlock_irqrestore(&xtime_lock, flags); + /* Look for timer events in tv1. */ + index = slot = timer_jiffies & TVR_MASK; + do { + list_for_each_entry(nte, base->tv1.vec + slot, entry) { + if (tbase_get_deferrable(nte->base)) + continue; - touch_softlockup_watchdog(); - hrtimer_notify_resume(); + found = 1; + expires = nte->expires; + /* Look at the cascade bucket(s)? */ + if (!index || slot < index) + goto cascade; + return expires; + } + slot = (slot + 1) & TVR_MASK; + } while (slot != index); - return 0; -} +cascade: + /* Calculate the next cascade event */ + if (index) + timer_jiffies += TVR_SIZE - index; + timer_jiffies >>= TVR_BITS; -static int timekeeping_suspend(struct sys_device *dev, pm_message_t state) -{ - unsigned long flags; + /* Check tv2-tv5. */ + varray[0] = &base->tv2; + varray[1] = &base->tv3; + varray[2] = &base->tv4; + varray[3] = &base->tv5; - write_seqlock_irqsave(&xtime_lock, flags); - timekeeping_suspended = 1; - timekeeping_suspend_time = read_persistent_clock(); - write_sequnlock_irqrestore(&xtime_lock, flags); - return 0; -} + for (array = 0; array < 4; array++) { + struct tvec *varp = varray[array]; -/* sysfs resume/suspend bits for timekeeping */ -static struct sysdev_class timekeeping_sysclass = { - .resume = timekeeping_resume, - .suspend = timekeeping_suspend, - set_kset_name("timekeeping"), -}; + index = slot = timer_jiffies & TVN_MASK; + do { + list_for_each_entry(nte, varp->vec + slot, entry) { + if (tbase_get_deferrable(nte->base)) + continue; -static struct sys_device device_timer = { - .id = 0, - .cls = &timekeeping_sysclass, -}; + found = 1; + if (time_before(nte->expires, expires)) + expires = nte->expires; + } + /* + * Do we still search for the first timer or are + * we looking up the cascade buckets ? + */ + if (found) { + /* Look at the cascade bucket(s)? */ + if (!index || slot < index) + break; + return expires; + } + slot = (slot + 1) & TVN_MASK; + } while (slot != index); -static int __init timekeeping_init_device(void) -{ - int error = sysdev_class_register(&timekeeping_sysclass); - if (!error) - error = sysdev_register(&device_timer); - return error; + if (index) + timer_jiffies += TVN_SIZE - index; + timer_jiffies >>= TVN_BITS; + } + return expires; } -device_initcall(timekeeping_init_device); - /* - * If the error is already larger, we look ahead even further - * to compensate for late or lost adjustments. + * Check, if the next hrtimer event is before the next timer wheel + * event: */ -static __always_inline int clocksource_bigadjust(s64 error, s64 *interval, - s64 *offset) +static unsigned long cmp_next_hrtimer_event(unsigned long now, + unsigned long expires) { - s64 tick_error, i; - u32 look_ahead, adj; - s32 error2, mult; + ktime_t hr_delta = hrtimer_get_next_event(); + struct timespec tsdelta; + unsigned long delta; - /* - * Use the current error value to determine how much to look ahead. - * The larger the error the slower we adjust for it to avoid problems - * with losing too many ticks, otherwise we would overadjust and - * produce an even larger error. The smaller the adjustment the - * faster we try to adjust for it, as lost ticks can do less harm - * here. This is tuned so that an error of about 1 msec is adusted - * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks). - */ - error2 = clock->error >> (TICK_LENGTH_SHIFT + 22 - 2 * SHIFT_HZ); - error2 = abs(error2); - for (look_ahead = 0; error2 > 0; look_ahead++) - error2 >>= 2; + if (hr_delta.tv64 == KTIME_MAX) + return expires; /* - * Now calculate the error in (1 << look_ahead) ticks, but first - * remove the single look ahead already included in the error. + * Expired timer available, let it expire in the next tick */ - tick_error = current_tick_length() >> - (TICK_LENGTH_SHIFT - clock->shift + 1); - tick_error -= clock->xtime_interval >> 1; - error = ((error - tick_error) >> look_ahead) + tick_error; - - /* Finally calculate the adjustment shift value. */ - i = *interval; - mult = 1; - if (error < 0) { - error = -error; - *interval = -*interval; - *offset = -*offset; - mult = -1; - } - for (adj = 0; error > i; adj++) - error >>= 1; + if (hr_delta.tv64 <= 0) + return now + 1; - *interval <<= adj; - *offset <<= adj; - return mult << adj; -} + tsdelta = ktime_to_timespec(hr_delta); + delta = timespec_to_jiffies(&tsdelta); -/* - * Adjust the multiplier to reduce the error value, - * this is optimized for the most common adjustments of -1,0,1, - * for other values we can do a bit more work. - */ -static void clocksource_adjust(struct clocksource *clock, s64 offset) -{ - s64 error, interval = clock->cycle_interval; - int adj; - - error = clock->error >> (TICK_LENGTH_SHIFT - clock->shift - 1); - if (error > interval) { - error >>= 2; - if (likely(error <= interval)) - adj = 1; - else - adj = clocksource_bigadjust(error, &interval, &offset); - } else if (error < -interval) { - error >>= 2; - if (likely(error >= -interval)) { - adj = -1; - interval = -interval; - offset = -offset; - } else - adj = clocksource_bigadjust(error, &interval, &offset); - } else - return; + /* + * Limit the delta to the max value, which is checked in + * tick_nohz_stop_sched_tick(): + */ + if (delta > NEXT_TIMER_MAX_DELTA) + delta = NEXT_TIMER_MAX_DELTA; - clock->mult += adj; - clock->xtime_interval += interval; - clock->xtime_nsec -= offset; - clock->error -= (interval - offset) << - (TICK_LENGTH_SHIFT - clock->shift); + /* + * Take rounding errors in to account and make sure, that it + * expires in the next tick. Otherwise we go into an endless + * ping pong due to tick_nohz_stop_sched_tick() retriggering + * the timer softirq + */ + if (delta < 1) + delta = 1; + now += delta; + if (time_before(now, expires)) + return now; + return expires; } /** - * update_wall_time - Uses the current clocksource to increment the wall time - * - * Called from the timer interrupt, must hold a write on xtime_lock. + * get_next_timer_interrupt - return the jiffy of the next pending timer + * @now: current time (in jiffies) */ -static void update_wall_time(void) +unsigned long get_next_timer_interrupt(unsigned long now) { - cycle_t offset; - - /* Make sure we're fully resumed: */ - if (unlikely(timekeeping_suspended)) - return; - -#ifdef CONFIG_GENERIC_TIME - offset = (clocksource_read(clock) - clock->cycle_last) & clock->mask; -#else - offset = clock->cycle_interval; -#endif - clock->xtime_nsec += (s64)xtime.tv_nsec << clock->shift; - - /* normally this loop will run just once, however in the - * case of lost or late ticks, it will accumulate correctly. - */ - while (offset >= clock->cycle_interval) { - /* accumulate one interval */ - clock->xtime_nsec += clock->xtime_interval; - clock->cycle_last += clock->cycle_interval; - offset -= clock->cycle_interval; - - if (clock->xtime_nsec >= (u64)NSEC_PER_SEC << clock->shift) { - clock->xtime_nsec -= (u64)NSEC_PER_SEC << clock->shift; - xtime.tv_sec++; - second_overflow(); - } - - /* interpolator bits */ - time_interpolator_update(clock->xtime_interval - >> clock->shift); - - /* accumulate error between NTP and clock interval */ - clock->error += current_tick_length(); - clock->error -= clock->xtime_interval << (TICK_LENGTH_SHIFT - clock->shift); - } + struct tvec_base *base = __get_cpu_var(tvec_bases); + unsigned long expires; - /* correct the clock when NTP error is too big */ - clocksource_adjust(clock, offset); + spin_lock(&base->lock); + if (time_before_eq(base->next_timer, base->timer_jiffies)) + base->next_timer = __next_timer_interrupt(base); + expires = base->next_timer; + spin_unlock(&base->lock); - /* store full nanoseconds into xtime */ - xtime.tv_nsec = (s64)clock->xtime_nsec >> clock->shift; - clock->xtime_nsec -= (s64)xtime.tv_nsec << clock->shift; + if (time_before_eq(expires, now)) + return now; - /* check to see if there is a new clocksource to use */ - change_clocksource(); + return cmp_next_hrtimer_event(now, expires); } +#endif /* - * Called from the timer interrupt handler to charge one tick to the current + * Called from the timer interrupt handler to charge one tick to the current * process. user_tick is 1 if the tick is user time, 0 for system. */ void update_process_times(int user_tick) @@ -1159,74 +1194,25 @@ void update_process_times(int user_tick) int cpu = smp_processor_id(); /* Note: this timer irq context must be accounted for as well. */ - if (user_tick) - account_user_time(p, jiffies_to_cputime(1)); - else - account_system_time(p, HARDIRQ_OFFSET, jiffies_to_cputime(1)); + account_process_tick(p, user_tick); run_local_timers(); - if (rcu_pending(cpu)) - rcu_check_callbacks(cpu, user_tick); + rcu_check_callbacks(cpu, user_tick); + printk_tick(); scheduler_tick(); - run_posix_cpu_timers(p); -} - -/* - * Nr of active tasks - counted in fixed-point numbers - */ -static unsigned long count_active_tasks(void) -{ - return nr_active() * FIXED_1; -} - -/* - * Hmm.. Changed this, as the GNU make sources (load.c) seems to - * imply that avenrun[] is the standard name for this kind of thing. - * Nothing else seems to be standardized: the fractional size etc - * all seem to differ on different machines. - * - * Requires xtime_lock to access. - */ -unsigned long avenrun[3]; - -EXPORT_SYMBOL(avenrun); - -/* - * calc_load - given tick count, update the avenrun load estimates. - * This is called while holding a write_lock on xtime_lock. - */ -static inline void calc_load(unsigned long ticks) -{ - unsigned long active_tasks; /* fixed-point */ - static int count = LOAD_FREQ; - - count -= ticks; - if (unlikely(count < 0)) { - active_tasks = count_active_tasks(); - do { - CALC_LOAD(avenrun[0], EXP_1, active_tasks); - CALC_LOAD(avenrun[1], EXP_5, active_tasks); - CALC_LOAD(avenrun[2], EXP_15, active_tasks); - count += LOAD_FREQ; - } while (count < 0); - } + run_posix_cpu_timers(p); } /* - * This read-write spinlock protects us from races in SMP while - * playing with xtime and avenrun. - */ -__attribute__((weak)) __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock); - -EXPORT_SYMBOL(xtime_lock); - -/* * This function runs timers and the timer-tq in bottom half context. */ static void run_timer_softirq(struct softirq_action *h) { - tvec_base_t *base = __get_cpu_var(tvec_bases); + struct tvec_base *base = __get_cpu_var(tvec_bases); + + perf_event_do_pending(); + + hrtimer_run_pending(); - hrtimer_run_queues(); if (time_after_eq(jiffies, base->timer_jiffies)) __run_timers(base); } @@ -1236,21 +1222,12 @@ static void run_timer_softirq(struct softirq_action *h) */ void run_local_timers(void) { + hrtimer_run_queues(); raise_softirq(TIMER_SOFTIRQ); softlockup_tick(); } /* - * Called by the timer interrupt. xtime_lock must already be taken - * by the timer IRQ! - */ -static inline void update_times(unsigned long ticks) -{ - update_wall_time(); - calc_load(ticks); -} - -/* * The 64-bit jiffies value is not atomic - you MUST NOT read it * without sampling the sequence number in xtime_lock. * jiffies is defined in the linker script... @@ -1259,7 +1236,8 @@ static inline void update_times(unsigned long ticks) void do_timer(unsigned long ticks) { jiffies_64 += ticks; - update_times(ticks); + update_wall_time(); + calc_global_load(); } #ifdef __ARCH_WANT_SYS_ALARM @@ -1268,7 +1246,7 @@ void do_timer(unsigned long ticks) * For backwards compatibility? This can be done in libc so Alpha * and all newer ports shouldn't need it. */ -asmlinkage unsigned long sys_alarm(unsigned int seconds) +SYSCALL_DEFINE1(alarm, unsigned int, seconds) { return alarm_setitimer(seconds); } @@ -1291,9 +1269,9 @@ asmlinkage unsigned long sys_alarm(unsigned int seconds) * * This is SMP safe as current->tgid does not change. */ -asmlinkage long sys_getpid(void) +SYSCALL_DEFINE0(getpid) { - return current->tgid; + return task_tgid_vnr(current); } /* @@ -1302,39 +1280,39 @@ asmlinkage long sys_getpid(void) * value of ->real_parent under rcu_read_lock(), see * release_task()->call_rcu(delayed_put_task_struct). */ -asmlinkage long sys_getppid(void) +SYSCALL_DEFINE0(getppid) { int pid; rcu_read_lock(); - pid = rcu_dereference(current->real_parent)->tgid; + pid = task_tgid_vnr(current->real_parent); rcu_read_unlock(); return pid; } -asmlinkage long sys_getuid(void) +SYSCALL_DEFINE0(getuid) { /* Only we change this so SMP safe */ - return current->uid; + return current_uid(); } -asmlinkage long sys_geteuid(void) +SYSCALL_DEFINE0(geteuid) { /* Only we change this so SMP safe */ - return current->euid; + return current_euid(); } -asmlinkage long sys_getgid(void) +SYSCALL_DEFINE0(getgid) { /* Only we change this so SMP safe */ - return current->gid; + return current_gid(); } -asmlinkage long sys_getegid(void) +SYSCALL_DEFINE0(getegid) { /* Only we change this so SMP safe */ - return current->egid; + return current_egid(); } #endif @@ -1370,7 +1348,7 @@ static void process_timeout(unsigned long __data) * * In all cases the return value is guaranteed to be non-negative. */ -fastcall signed long __sched schedule_timeout(signed long timeout) +signed long __sched schedule_timeout(signed long timeout) { struct timer_list timer; unsigned long expire; @@ -1406,11 +1384,14 @@ fastcall signed long __sched schedule_timeout(signed long timeout) expire = timeout + jiffies; - setup_timer(&timer, process_timeout, (unsigned long)current); - __mod_timer(&timer, expire); + setup_timer_on_stack(&timer, process_timeout, (unsigned long)current); + __mod_timer(&timer, expire, false, TIMER_NOT_PINNED); schedule(); del_singleshot_timer_sync(&timer); + /* Remove the timer from the object tracker */ + destroy_timer_on_stack(&timer); + timeout = expire - jiffies; out: @@ -1429,6 +1410,13 @@ signed long __sched schedule_timeout_interruptible(signed long timeout) } EXPORT_SYMBOL(schedule_timeout_interruptible); +signed long __sched schedule_timeout_killable(signed long timeout) +{ + __set_current_state(TASK_KILLABLE); + return schedule_timeout(timeout); +} +EXPORT_SYMBOL(schedule_timeout_killable); + signed long __sched schedule_timeout_uninterruptible(signed long timeout) { __set_current_state(TASK_UNINTERRUPTIBLE); @@ -1437,49 +1425,30 @@ signed long __sched schedule_timeout_uninterruptible(signed long timeout) EXPORT_SYMBOL(schedule_timeout_uninterruptible); /* Thread ID - the internal kernel "pid" */ -asmlinkage long sys_gettid(void) +SYSCALL_DEFINE0(gettid) { - return current->pid; + return task_pid_vnr(current); } /** * do_sysinfo - fill in sysinfo struct * @info: pointer to buffer to fill - */ + */ int do_sysinfo(struct sysinfo *info) { unsigned long mem_total, sav_total; unsigned int mem_unit, bitcount; - unsigned long seq; + struct timespec tp; memset(info, 0, sizeof(struct sysinfo)); - do { - struct timespec tp; - seq = read_seqbegin(&xtime_lock); - - /* - * This is annoying. The below is the same thing - * posix_get_clock_monotonic() does, but it wants to - * take the lock which we want to cover the loads stuff - * too. - */ - - getnstimeofday(&tp); - tp.tv_sec += wall_to_monotonic.tv_sec; - tp.tv_nsec += wall_to_monotonic.tv_nsec; - if (tp.tv_nsec - NSEC_PER_SEC >= 0) { - tp.tv_nsec = tp.tv_nsec - NSEC_PER_SEC; - tp.tv_sec++; - } - info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); + ktime_get_ts(&tp); + monotonic_to_bootbased(&tp); + info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); - info->loads[0] = avenrun[0] << (SI_LOAD_SHIFT - FSHIFT); - info->loads[1] = avenrun[1] << (SI_LOAD_SHIFT - FSHIFT); - info->loads[2] = avenrun[2] << (SI_LOAD_SHIFT - FSHIFT); + get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); - info->procs = nr_threads; - } while (read_seqretry(&xtime_lock, seq)); + info->procs = nr_threads; si_meminfo(info); si_swapinfo(info); @@ -1528,7 +1497,7 @@ out: return 0; } -asmlinkage long sys_sysinfo(struct sysinfo __user *info) +SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) { struct sysinfo val; @@ -1540,18 +1509,11 @@ asmlinkage long sys_sysinfo(struct sysinfo __user *info) return 0; } -/* - * lockdep: we want to track each per-CPU base as a separate lock-class, - * but timer-bases are kmalloc()-ed, so we need to attach separate - * keys to them: - */ -static struct lock_class_key base_lock_keys[NR_CPUS]; - -static int __devinit init_timers_cpu(int cpu) +static int __cpuinit init_timers_cpu(int cpu) { int j; - tvec_base_t *base; - static char __devinitdata tvec_base_done[NR_CPUS]; + struct tvec_base *base; + static char __cpuinitdata tvec_base_done[NR_CPUS]; if (!tvec_base_done[cpu]) { static char boot_done; @@ -1560,11 +1522,18 @@ static int __devinit init_timers_cpu(int cpu) /* * The APs use this path later in boot */ - base = kmalloc_node(sizeof(*base), GFP_KERNEL, + base = kmalloc_node(sizeof(*base), + GFP_KERNEL | __GFP_ZERO, cpu_to_node(cpu)); if (!base) return -ENOMEM; - memset(base, 0, sizeof(*base)); + + /* Make sure that tvec_base is 2 byte aligned */ + if (tbase_get_deferrable(base)) { + WARN_ON(1); + kfree(base); + return -ENOMEM; + } per_cpu(tvec_bases, cpu) = base; } else { /* @@ -1582,7 +1551,6 @@ static int __devinit init_timers_cpu(int cpu) } spin_lock_init(&base->lock); - lockdep_set_class(&base->lock, base_lock_keys + cpu); for (j = 0; j < TVN_SIZE; j++) { INIT_LIST_HEAD(base->tv5.vec + j); @@ -1594,35 +1562,41 @@ static int __devinit init_timers_cpu(int cpu) INIT_LIST_HEAD(base->tv1.vec + j); base->timer_jiffies = jiffies; + base->next_timer = base->timer_jiffies; return 0; } #ifdef CONFIG_HOTPLUG_CPU -static void migrate_timer_list(tvec_base_t *new_base, struct list_head *head) +static void migrate_timer_list(struct tvec_base *new_base, struct list_head *head) { struct timer_list *timer; while (!list_empty(head)) { - timer = list_entry(head->next, struct timer_list, entry); + timer = list_first_entry(head, struct timer_list, entry); detach_timer(timer, 0); - timer->base = new_base; + timer_set_base(timer, new_base); + if (time_before(timer->expires, new_base->next_timer) && + !tbase_get_deferrable(timer->base)) + new_base->next_timer = timer->expires; internal_add_timer(new_base, timer); } } -static void __devinit migrate_timers(int cpu) +static void __cpuinit migrate_timers(int cpu) { - tvec_base_t *old_base; - tvec_base_t *new_base; + struct tvec_base *old_base; + struct tvec_base *new_base; int i; BUG_ON(cpu_online(cpu)); old_base = per_cpu(tvec_bases, cpu); new_base = get_cpu_var(tvec_bases); - - local_irq_disable(); - spin_lock(&new_base->lock); - spin_lock(&old_base->lock); + /* + * The caller is globally serialized and nobody else + * takes two locks at once, deadlock is not possible. + */ + spin_lock_irq(&new_base->lock); + spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING); BUG_ON(old_base->running_timer); @@ -1636,8 +1610,7 @@ static void __devinit migrate_timers(int cpu) } spin_unlock(&old_base->lock); - spin_unlock(&new_base->lock); - local_irq_enable(); + spin_unlock_irq(&new_base->lock); put_cpu_var(tvec_bases); } #endif /* CONFIG_HOTPLUG_CPU */ @@ -1648,11 +1621,13 @@ static int __cpuinit timer_cpu_notify(struct notifier_block *self, long cpu = (long)hcpu; switch(action) { case CPU_UP_PREPARE: + case CPU_UP_PREPARE_FROZEN: if (init_timers_cpu(cpu) < 0) return NOTIFY_BAD; break; #ifdef CONFIG_HOTPLUG_CPU case CPU_DEAD: + case CPU_DEAD_FROZEN: migrate_timers(cpu); break; #endif @@ -1672,198 +1647,12 @@ void __init init_timers(void) int err = timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE, (void *)(long)smp_processor_id()); + init_timer_stats(); + BUG_ON(err == NOTIFY_BAD); register_cpu_notifier(&timers_nb); - open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL); -} - -#ifdef CONFIG_TIME_INTERPOLATION - -struct time_interpolator *time_interpolator __read_mostly; -static struct time_interpolator *time_interpolator_list __read_mostly; -static DEFINE_SPINLOCK(time_interpolator_lock); - -static inline cycles_t time_interpolator_get_cycles(unsigned int src) -{ - unsigned long (*x)(void); - - switch (src) - { - case TIME_SOURCE_FUNCTION: - x = time_interpolator->addr; - return x(); - - case TIME_SOURCE_MMIO64 : - return readq_relaxed((void __iomem *)time_interpolator->addr); - - case TIME_SOURCE_MMIO32 : - return readl_relaxed((void __iomem *)time_interpolator->addr); - - default: return get_cycles(); - } -} - -static inline u64 time_interpolator_get_counter(int writelock) -{ - unsigned int src = time_interpolator->source; - - if (time_interpolator->jitter) - { - cycles_t lcycle; - cycles_t now; - - do { - lcycle = time_interpolator->last_cycle; - now = time_interpolator_get_cycles(src); - if (lcycle && time_after(lcycle, now)) - return lcycle; - - /* When holding the xtime write lock, there's no need - * to add the overhead of the cmpxchg. Readers are - * force to retry until the write lock is released. - */ - if (writelock) { - time_interpolator->last_cycle = now; - return now; - } - /* Keep track of the last timer value returned. The use of cmpxchg here - * will cause contention in an SMP environment. - */ - } while (unlikely(cmpxchg(&time_interpolator->last_cycle, lcycle, now) != lcycle)); - return now; - } - else - return time_interpolator_get_cycles(src); -} - -void time_interpolator_reset(void) -{ - time_interpolator->offset = 0; - time_interpolator->last_counter = time_interpolator_get_counter(1); -} - -#define GET_TI_NSECS(count,i) (((((count) - i->last_counter) & (i)->mask) * (i)->nsec_per_cyc) >> (i)->shift) - -unsigned long time_interpolator_get_offset(void) -{ - /* If we do not have a time interpolator set up then just return zero */ - if (!time_interpolator) - return 0; - - return time_interpolator->offset + - GET_TI_NSECS(time_interpolator_get_counter(0), time_interpolator); -} - -#define INTERPOLATOR_ADJUST 65536 -#define INTERPOLATOR_MAX_SKIP 10*INTERPOLATOR_ADJUST - -void time_interpolator_update(long delta_nsec) -{ - u64 counter; - unsigned long offset; - - /* If there is no time interpolator set up then do nothing */ - if (!time_interpolator) - return; - - /* - * The interpolator compensates for late ticks by accumulating the late - * time in time_interpolator->offset. A tick earlier than expected will - * lead to a reset of the offset and a corresponding jump of the clock - * forward. Again this only works if the interpolator clock is running - * slightly slower than the regular clock and the tuning logic insures - * that. - */ - - counter = time_interpolator_get_counter(1); - offset = time_interpolator->offset + - GET_TI_NSECS(counter, time_interpolator); - - if (delta_nsec < 0 || (unsigned long) delta_nsec < offset) - time_interpolator->offset = offset - delta_nsec; - else { - time_interpolator->skips++; - time_interpolator->ns_skipped += delta_nsec - offset; - time_interpolator->offset = 0; - } - time_interpolator->last_counter = counter; - - /* Tuning logic for time interpolator invoked every minute or so. - * Decrease interpolator clock speed if no skips occurred and an offset is carried. - * Increase interpolator clock speed if we skip too much time. - */ - if (jiffies % INTERPOLATOR_ADJUST == 0) - { - if (time_interpolator->skips == 0 && time_interpolator->offset > tick_nsec) - time_interpolator->nsec_per_cyc--; - if (time_interpolator->ns_skipped > INTERPOLATOR_MAX_SKIP && time_interpolator->offset == 0) - time_interpolator->nsec_per_cyc++; - time_interpolator->skips = 0; - time_interpolator->ns_skipped = 0; - } -} - -static inline int -is_better_time_interpolator(struct time_interpolator *new) -{ - if (!time_interpolator) - return 1; - return new->frequency > 2*time_interpolator->frequency || - (unsigned long)new->drift < (unsigned long)time_interpolator->drift; -} - -void -register_time_interpolator(struct time_interpolator *ti) -{ - unsigned long flags; - - /* Sanity check */ - BUG_ON(ti->frequency == 0 || ti->mask == 0); - - ti->nsec_per_cyc = ((u64)NSEC_PER_SEC << ti->shift) / ti->frequency; - spin_lock(&time_interpolator_lock); - write_seqlock_irqsave(&xtime_lock, flags); - if (is_better_time_interpolator(ti)) { - time_interpolator = ti; - time_interpolator_reset(); - } - write_sequnlock_irqrestore(&xtime_lock, flags); - - ti->next = time_interpolator_list; - time_interpolator_list = ti; - spin_unlock(&time_interpolator_lock); -} - -void -unregister_time_interpolator(struct time_interpolator *ti) -{ - struct time_interpolator *curr, **prev; - unsigned long flags; - - spin_lock(&time_interpolator_lock); - prev = &time_interpolator_list; - for (curr = *prev; curr; curr = curr->next) { - if (curr == ti) { - *prev = curr->next; - break; - } - prev = &curr->next; - } - - write_seqlock_irqsave(&xtime_lock, flags); - if (ti == time_interpolator) { - /* we lost the best time-interpolator: */ - time_interpolator = NULL; - /* find the next-best interpolator */ - for (curr = time_interpolator_list; curr; curr = curr->next) - if (is_better_time_interpolator(curr)) - time_interpolator = curr; - time_interpolator_reset(); - } - write_sequnlock_irqrestore(&xtime_lock, flags); - spin_unlock(&time_interpolator_lock); + open_softirq(TIMER_SOFTIRQ, run_timer_softirq); } -#endif /* CONFIG_TIME_INTERPOLATION */ /** * msleep - sleep safely even with waitqueue interruptions