diff options
Diffstat (limited to 'kernel/timer.c')
-rw-r--r-- | kernel/timer.c | 126 |
1 files changed, 59 insertions, 67 deletions
diff --git a/kernel/timer.c b/kernel/timer.c index ab189dd187c..88377378883 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -54,7 +54,6 @@ EXPORT_SYMBOL(jiffies_64); /* * per-CPU timer vector definitions: */ - #define TVN_BITS (CONFIG_BASE_SMALL ? 4 : 6) #define TVR_BITS (CONFIG_BASE_SMALL ? 6 : 8) #define TVN_SIZE (1 << TVN_BITS) @@ -62,11 +61,6 @@ EXPORT_SYMBOL(jiffies_64); #define TVN_MASK (TVN_SIZE - 1) #define TVR_MASK (TVR_SIZE - 1) -struct timer_base_s { - spinlock_t lock; - struct timer_list *running_timer; -}; - typedef struct tvec_s { struct list_head vec[TVN_SIZE]; } tvec_t; @@ -76,7 +70,8 @@ typedef struct tvec_root_s { } tvec_root_t; struct tvec_t_base_s { - struct timer_base_s t_base; + spinlock_t lock; + struct timer_list *running_timer; unsigned long timer_jiffies; tvec_root_t tv1; tvec_t tv2; @@ -86,14 +81,16 @@ struct tvec_t_base_s { } ____cacheline_aligned_in_smp; typedef struct tvec_t_base_s tvec_base_t; -static DEFINE_PER_CPU(tvec_base_t *, tvec_bases); -static tvec_base_t boot_tvec_bases; + +tvec_base_t boot_tvec_bases; +EXPORT_SYMBOL(boot_tvec_bases); +static DEFINE_PER_CPU(tvec_base_t *, tvec_bases) = { &boot_tvec_bases }; static inline void set_running_timer(tvec_base_t *base, struct timer_list *timer) { #ifdef CONFIG_SMP - base->t_base.running_timer = timer; + base->running_timer = timer; #endif } @@ -139,15 +136,6 @@ static void internal_add_timer(tvec_base_t *base, struct timer_list *timer) list_add_tail(&timer->entry, vec); } -typedef struct timer_base_s timer_base_t; -/* - * Used by TIMER_INITIALIZER, we can't use per_cpu(tvec_bases) - * at compile time, and we need timer->base to lock the timer. - */ -timer_base_t __init_timer_base - ____cacheline_aligned_in_smp = { .lock = SPIN_LOCK_UNLOCKED }; -EXPORT_SYMBOL(__init_timer_base); - /*** * init_timer - initialize a timer. * @timer: the timer to be initialized @@ -158,7 +146,7 @@ EXPORT_SYMBOL(__init_timer_base); void fastcall init_timer(struct timer_list *timer) { timer->entry.next = NULL; - timer->base = &per_cpu(tvec_bases, raw_smp_processor_id())->t_base; + timer->base = per_cpu(tvec_bases, raw_smp_processor_id()); } EXPORT_SYMBOL(init_timer); @@ -174,7 +162,7 @@ static inline void detach_timer(struct timer_list *timer, } /* - * We are using hashed locking: holding per_cpu(tvec_bases).t_base.lock + * We are using hashed locking: holding per_cpu(tvec_bases).lock * means that all timers which are tied to this base via timer->base are * locked, and the base itself is locked too. * @@ -185,10 +173,10 @@ static inline void detach_timer(struct timer_list *timer, * possible to set timer->base = NULL and drop the lock: the timer remains * locked. */ -static timer_base_t *lock_timer_base(struct timer_list *timer, +static tvec_base_t *lock_timer_base(struct timer_list *timer, unsigned long *flags) { - timer_base_t *base; + tvec_base_t *base; for (;;) { base = timer->base; @@ -205,8 +193,7 @@ static timer_base_t *lock_timer_base(struct timer_list *timer, int __mod_timer(struct timer_list *timer, unsigned long expires) { - timer_base_t *base; - tvec_base_t *new_base; + tvec_base_t *base, *new_base; unsigned long flags; int ret = 0; @@ -221,7 +208,7 @@ int __mod_timer(struct timer_list *timer, unsigned long expires) new_base = __get_cpu_var(tvec_bases); - if (base != &new_base->t_base) { + if (base != new_base) { /* * We are trying to schedule the timer on the local CPU. * However we can't change timer's base while it is running, @@ -229,21 +216,19 @@ int __mod_timer(struct timer_list *timer, unsigned long expires) * handler yet has not finished. This also guarantees that * the timer is serialized wrt itself. */ - if (unlikely(base->running_timer == timer)) { - /* The timer remains on a former base */ - new_base = container_of(base, tvec_base_t, t_base); - } else { + if (likely(base->running_timer != timer)) { /* See the comment in lock_timer_base() */ timer->base = NULL; spin_unlock(&base->lock); - spin_lock(&new_base->t_base.lock); - timer->base = &new_base->t_base; + base = new_base; + spin_lock(&base->lock); + timer->base = base; } } timer->expires = expires; - internal_add_timer(new_base, timer); - spin_unlock_irqrestore(&new_base->t_base.lock, flags); + internal_add_timer(base, timer); + spin_unlock_irqrestore(&base->lock, flags); return ret; } @@ -263,10 +248,10 @@ void add_timer_on(struct timer_list *timer, int cpu) unsigned long flags; BUG_ON(timer_pending(timer) || !timer->function); - spin_lock_irqsave(&base->t_base.lock, flags); - timer->base = &base->t_base; + spin_lock_irqsave(&base->lock, flags); + timer->base = base; internal_add_timer(base, timer); - spin_unlock_irqrestore(&base->t_base.lock, flags); + spin_unlock_irqrestore(&base->lock, flags); } @@ -319,7 +304,7 @@ EXPORT_SYMBOL(mod_timer); */ int del_timer(struct timer_list *timer) { - timer_base_t *base; + tvec_base_t *base; unsigned long flags; int ret = 0; @@ -346,7 +331,7 @@ EXPORT_SYMBOL(del_timer); */ int try_to_del_timer_sync(struct timer_list *timer) { - timer_base_t *base; + tvec_base_t *base; unsigned long flags; int ret = -1; @@ -410,7 +395,7 @@ static int cascade(tvec_base_t *base, tvec_t *tv, int index) struct timer_list *tmp; tmp = list_entry(curr, struct timer_list, entry); - BUG_ON(tmp->base != &base->t_base); + BUG_ON(tmp->base != base); curr = curr->next; internal_add_timer(base, tmp); } @@ -432,7 +417,7 @@ static inline void __run_timers(tvec_base_t *base) { struct timer_list *timer; - spin_lock_irq(&base->t_base.lock); + spin_lock_irq(&base->lock); while (time_after_eq(jiffies, base->timer_jiffies)) { struct list_head work_list = LIST_HEAD_INIT(work_list); struct list_head *head = &work_list; @@ -458,7 +443,7 @@ static inline void __run_timers(tvec_base_t *base) set_running_timer(base, timer); detach_timer(timer, 1); - spin_unlock_irq(&base->t_base.lock); + spin_unlock_irq(&base->lock); { int preempt_count = preempt_count(); fn(data); @@ -471,11 +456,11 @@ static inline void __run_timers(tvec_base_t *base) BUG(); } } - spin_lock_irq(&base->t_base.lock); + spin_lock_irq(&base->lock); } } set_running_timer(base, NULL); - spin_unlock_irq(&base->t_base.lock); + spin_unlock_irq(&base->lock); } #ifdef CONFIG_NO_IDLE_HZ @@ -506,7 +491,7 @@ unsigned long next_timer_interrupt(void) hr_expires += jiffies; base = __get_cpu_var(tvec_bases); - spin_lock(&base->t_base.lock); + spin_lock(&base->lock); expires = base->timer_jiffies + (LONG_MAX >> 1); list = NULL; @@ -554,7 +539,7 @@ found: expires = nte->expires; } } - spin_unlock(&base->t_base.lock); + spin_unlock(&base->lock); if (time_before(hr_expires, expires)) return hr_expires; @@ -841,7 +826,7 @@ void update_process_times(int user_tick) */ static unsigned long count_active_tasks(void) { - return (nr_running() + nr_uninterruptible()) * FIXED_1; + return nr_active() * FIXED_1; } /* @@ -1240,29 +1225,37 @@ static int __devinit init_timers_cpu(int cpu) { int j; tvec_base_t *base; + static char __devinitdata tvec_base_done[NR_CPUS]; - base = per_cpu(tvec_bases, cpu); - if (!base) { + if (!tvec_base_done[cpu]) { static char boot_done; - /* - * Cannot do allocation in init_timers as that runs before the - * allocator initializes (and would waste memory if there are - * more possible CPUs than will ever be installed/brought up). - */ if (boot_done) { + /* + * The APs use this path later in boot + */ base = kmalloc_node(sizeof(*base), GFP_KERNEL, cpu_to_node(cpu)); if (!base) return -ENOMEM; memset(base, 0, sizeof(*base)); + per_cpu(tvec_bases, cpu) = base; } else { - base = &boot_tvec_bases; + /* + * This is for the boot CPU - we use compile-time + * static initialisation because per-cpu memory isn't + * ready yet and because the memory allocators are not + * initialised either. + */ boot_done = 1; + base = &boot_tvec_bases; } - per_cpu(tvec_bases, cpu) = base; + tvec_base_done[cpu] = 1; + } else { + base = per_cpu(tvec_bases, cpu); } - spin_lock_init(&base->t_base.lock); + + spin_lock_init(&base->lock); for (j = 0; j < TVN_SIZE; j++) { INIT_LIST_HEAD(base->tv5.vec + j); INIT_LIST_HEAD(base->tv4.vec + j); @@ -1284,7 +1277,7 @@ static void migrate_timer_list(tvec_base_t *new_base, struct list_head *head) while (!list_empty(head)) { timer = list_entry(head->next, struct timer_list, entry); detach_timer(timer, 0); - timer->base = &new_base->t_base; + timer->base = new_base; internal_add_timer(new_base, timer); } } @@ -1300,11 +1293,11 @@ static void __devinit migrate_timers(int cpu) new_base = get_cpu_var(tvec_bases); local_irq_disable(); - spin_lock(&new_base->t_base.lock); - spin_lock(&old_base->t_base.lock); + spin_lock(&new_base->lock); + spin_lock(&old_base->lock); + + BUG_ON(old_base->running_timer); - if (old_base->t_base.running_timer) - BUG(); for (i = 0; i < TVR_SIZE; i++) migrate_timer_list(new_base, old_base->tv1.vec + i); for (i = 0; i < TVN_SIZE; i++) { @@ -1314,8 +1307,8 @@ static void __devinit migrate_timers(int cpu) migrate_timer_list(new_base, old_base->tv5.vec + i); } - spin_unlock(&old_base->t_base.lock); - spin_unlock(&new_base->t_base.lock); + spin_unlock(&old_base->lock); + spin_unlock(&new_base->lock); local_irq_enable(); put_cpu_var(tvec_bases); } @@ -1471,7 +1464,7 @@ static void time_interpolator_update(long delta_nsec) */ if (jiffies % INTERPOLATOR_ADJUST == 0) { - if (time_interpolator->skips == 0 && time_interpolator->offset > TICK_NSEC) + 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++; @@ -1495,8 +1488,7 @@ register_time_interpolator(struct time_interpolator *ti) unsigned long flags; /* Sanity check */ - if (ti->frequency == 0 || ti->mask == 0) - BUG(); + 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); |