summaryrefslogtreecommitdiffstats
path: root/kernel/timer.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/timer.c')
-rw-r--r--kernel/timer.c166
1 files changed, 76 insertions, 90 deletions
diff --git a/kernel/timer.c b/kernel/timer.c
index bf7c4193b93..6b812c04737 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;
@@ -86,13 +81,15 @@ 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 DEFINE_PER_CPU(tvec_base_t *, tvec_bases);
+tvec_base_t boot_tvec_bases;
+EXPORT_SYMBOL(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
}
@@ -138,15 +135,6 @@ 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
@@ -157,7 +145,7 @@ 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);
@@ -173,7 +161,7 @@ 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.
*
@@ -184,10 +172,10 @@ 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;
@@ -204,8 +192,7 @@ 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;
@@ -218,9 +205,9 @@ int __mod_timer(struct timer_list *timer, unsigned long expires)
ret = 1;
}
- new_base = &__get_cpu_var(tvec_bases);
+ 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,
@@ -228,21 +215,19 @@ 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;
}
@@ -258,14 +243,14 @@ EXPORT_SYMBOL(__mod_timer);
*/
void add_timer_on(struct timer_list *timer, int cpu)
{
- tvec_base_t *base = &per_cpu(tvec_bases, cpu);
+ tvec_base_t *base = per_cpu(tvec_bases, 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);
}
@@ -318,7 +303,7 @@ 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;
@@ -345,7 +330,7 @@ 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;
@@ -409,7 +394,7 @@ 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);
}
@@ -431,7 +416,7 @@ 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;
@@ -457,7 +442,7 @@ 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);
@@ -470,11 +455,11 @@ 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
@@ -504,8 +489,8 @@ unsigned long next_timer_interrupt(void)
}
hr_expires += jiffies;
- base = &__get_cpu_var(tvec_bases);
- spin_lock(&base->t_base.lock);
+ base = __get_cpu_var(tvec_bases);
+ spin_lock(&base->lock);
expires = base->timer_jiffies + (LONG_MAX >> 1);
list = NULL;
@@ -553,7 +538,7 @@ found:
expires = nte->expires;
}
}
- spin_unlock(&base->t_base.lock);
+ spin_unlock(&base->lock);
if (time_before(hr_expires, expires))
return hr_expires;
@@ -696,18 +681,9 @@ static void second_overflow(void)
/*
* Compute the frequency estimate and additional phase adjustment due
- * to frequency error for the next second. When the PPS signal is
- * engaged, gnaw on the watchdog counter and update the frequency
- * computed by the pll and the PPS signal.
+ * to frequency error for the next second.
*/
- pps_valid++;
- if (pps_valid == PPS_VALID) { /* PPS signal lost */
- pps_jitter = MAXTIME;
- pps_stabil = MAXFREQ;
- time_status &= ~(STA_PPSSIGNAL | STA_PPSJITTER |
- STA_PPSWANDER | STA_PPSERROR);
- }
- ltemp = time_freq + pps_freq;
+ ltemp = time_freq;
time_adj += shift_right(ltemp,(SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE));
#if HZ == 100
@@ -849,7 +825,7 @@ 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;
}
/*
@@ -901,7 +877,7 @@ EXPORT_SYMBOL(xtime_lock);
*/
static void run_timer_softirq(struct softirq_action *h)
{
- tvec_base_t *base = &__get_cpu_var(tvec_bases);
+ tvec_base_t *base = __get_cpu_var(tvec_bases);
hrtimer_run_queues();
if (time_after_eq(jiffies, base->timer_jiffies))
@@ -914,6 +890,7 @@ static void run_timer_softirq(struct softirq_action *h)
void run_local_timers(void)
{
raise_softirq(TIMER_SOFTIRQ);
+ softlockup_tick();
}
/*
@@ -944,7 +921,6 @@ void do_timer(struct pt_regs *regs)
/* prevent loading jiffies before storing new jiffies_64 value. */
barrier();
update_times();
- softlockup_tick(regs);
}
#ifdef __ARCH_WANT_SYS_ALARM
@@ -955,19 +931,7 @@ void do_timer(struct pt_regs *regs)
*/
asmlinkage unsigned long sys_alarm(unsigned int seconds)
{
- struct itimerval it_new, it_old;
- unsigned int oldalarm;
-
- it_new.it_interval.tv_sec = it_new.it_interval.tv_usec = 0;
- it_new.it_value.tv_sec = seconds;
- it_new.it_value.tv_usec = 0;
- do_setitimer(ITIMER_REAL, &it_new, &it_old);
- oldalarm = it_old.it_value.tv_sec;
- /* ehhh.. We can't return 0 if we have an alarm pending.. */
- /* And we'd better return too much than too little anyway */
- if ((!oldalarm && it_old.it_value.tv_usec) || it_old.it_value.tv_usec >= 500000)
- oldalarm++;
- return oldalarm;
+ return alarm_setitimer(seconds);
}
#endif
@@ -1256,13 +1220,33 @@ asmlinkage long sys_sysinfo(struct sysinfo __user *info)
return 0;
}
-static void __devinit init_timers_cpu(int cpu)
+static int __devinit init_timers_cpu(int cpu)
{
int j;
tvec_base_t *base;
- base = &per_cpu(tvec_bases, cpu);
- spin_lock_init(&base->t_base.lock);
+ base = per_cpu(tvec_bases, cpu);
+ if (!base) {
+ 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) {
+ base = kmalloc_node(sizeof(*base), GFP_KERNEL,
+ cpu_to_node(cpu));
+ if (!base)
+ return -ENOMEM;
+ memset(base, 0, sizeof(*base));
+ } else {
+ base = &boot_tvec_bases;
+ boot_done = 1;
+ }
+ per_cpu(tvec_bases, cpu) = base;
+ }
+ 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);
@@ -1273,6 +1257,7 @@ static void __devinit init_timers_cpu(int cpu)
INIT_LIST_HEAD(base->tv1.vec + j);
base->timer_jiffies = jiffies;
+ return 0;
}
#ifdef CONFIG_HOTPLUG_CPU
@@ -1283,7 +1268,7 @@ 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);
}
}
@@ -1295,15 +1280,15 @@ static void __devinit migrate_timers(int cpu)
int i;
BUG_ON(cpu_online(cpu));
- old_base = &per_cpu(tvec_bases, cpu);
- new_base = &get_cpu_var(tvec_bases);
+ old_base = per_cpu(tvec_bases, 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++) {
@@ -1313,8 +1298,8 @@ 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);
}
@@ -1326,7 +1311,8 @@ static int __devinit timer_cpu_notify(struct notifier_block *self,
long cpu = (long)hcpu;
switch(action) {
case CPU_UP_PREPARE:
- init_timers_cpu(cpu);
+ if (init_timers_cpu(cpu) < 0)
+ return NOTIFY_BAD;
break;
#ifdef CONFIG_HOTPLUG_CPU
case CPU_DEAD:
@@ -1354,8 +1340,8 @@ void __init init_timers(void)
#ifdef CONFIG_TIME_INTERPOLATION
-struct time_interpolator *time_interpolator;
-static struct time_interpolator *time_interpolator_list;
+struct time_interpolator *time_interpolator __read_mostly;
+static struct time_interpolator *time_interpolator_list __read_mostly;
static DEFINE_SPINLOCK(time_interpolator_lock);
static inline u64 time_interpolator_get_cycles(unsigned int src)