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-rw-r--r--kernel/timer.c126
1 files changed, 59 insertions, 67 deletions
diff --git a/kernel/timer.c b/kernel/timer.c
index ab189dd187cb..883773788836 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);