/*
* 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
*
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/swap.h>
+#include <linux/pid_namespace.h>
#include <linux/notifier.h>
#include <linux/thread_info.h>
#include <linux/time.h>
#include <linux/posix-timers.h>
#include <linux/cpu.h>
#include <linux/syscalls.h>
+#include <linux/delay.h>
+#include <linux/tick.h>
+#include <linux/kallsyms.h>
+#include <linux/perf_event.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
#include <asm/timex.h>
#include <asm/io.h>
-#ifdef CONFIG_TIME_INTERPOLATION
-static void time_interpolator_update(long delta_nsec);
-#else
-#define time_interpolator_update(x)
-#endif
+#define CREATE_TRACE_POINTS
+#include <trace/events/timer.h>
+
+u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES;
+
+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)
#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 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 timer_base_s t_base;
+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;
+ 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(struct tvec_base *, tvec_bases) = &boot_tvec_bases;
-typedef struct tvec_t_base_s tvec_base_t;
-static DEFINE_PER_CPU(tvec_base_t, tvec_bases);
+/*
+ * 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
+ */
+#define TBASE_DEFERRABLE_FLAG (0x1)
-static inline void set_running_timer(tvec_base_t *base,
- struct timer_list *timer)
+/* Functions below help us manage 'deferrable' flag */
+static inline unsigned int tbase_get_deferrable(struct tvec_base *base)
{
-#ifdef CONFIG_SMP
- base->t_base.running_timer = timer;
-#endif
+ return ((unsigned int)(unsigned long)base & TBASE_DEFERRABLE_FLAG);
}
-static void check_timer_failed(struct timer_list *timer)
+static inline struct tvec_base *tbase_get_base(struct tvec_base *base)
{
- static int whine_count;
- if (whine_count < 16) {
- whine_count++;
- printk("Uninitialised timer!\n");
- printk("This is just a warning. Your computer is OK\n");
- printk("function=0x%p, data=0x%lx\n",
- timer->function, timer->data);
- dump_stack();
- }
+ 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;
+
/*
- * Now fix it up
+ * We don't want all cpus firing their timers at once hitting the
+ * same lock or cachelines, so we skew each extra cpu with an extra
+ * 3 jiffies. This 3 jiffies came originally from the mm/ code which
+ * already did this.
+ * The skew is done by adding 3*cpunr, then round, then subtract this
+ * extra offset again.
*/
- timer->magic = TIMER_MAGIC;
+ j += cpu * 3;
+
+ rem = j % HZ;
+
+ /*
+ * If the target jiffie is just after a whole second (which can happen
+ * 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 && !force_up) /* round down */
+ j = j - rem;
+ else /* round up */
+ j = j - rem + HZ;
+
+ /* now that we have rounded, subtract the extra skew again */
+ j -= cpu * 3;
+
+ if (j <= jiffies) /* rounding ate our timeout entirely; */
+ 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);
+
+/**
+ * __round_jiffies_relative - function to round jiffies to a full second
+ * @j: the time in (relative) jiffies that should be rounded
+ * @cpu: the processor number on which the timeout will happen
+ *
+ * __round_jiffies_relative() rounds a time delta 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_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, false) - j0;
+}
+EXPORT_SYMBOL_GPL(__round_jiffies_relative);
+
+/**
+ * round_jiffies - function to round jiffies to a full second
+ * @j: the time in (absolute) jiffies that should be rounded
+ *
+ * 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 return value is the rounded version of the @j parameter.
+ */
+unsigned long round_jiffies(unsigned long j)
+{
+ return round_jiffies_common(j, raw_smp_processor_id(), false);
+}
+EXPORT_SYMBOL_GPL(round_jiffies);
+
+/**
+ * round_jiffies_relative - function to round jiffies to a full second
+ * @j: the time in (relative) jiffies that should be rounded
+ *
+ * round_jiffies_relative() rounds a time delta 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 return value is the rounded version of the @j parameter.
+ */
+unsigned long round_jiffies_relative(unsigned long j)
+{
+ return __round_jiffies_relative(j, raw_smp_processor_id());
+}
+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);
+
+/**
+ * __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);
-static inline void check_timer(struct timer_list *timer)
+/**
+ * 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)
{
- if (timer->magic != TIMER_MAGIC)
- check_timer_failed(timer);
+ return __round_jiffies_up_relative(j, raw_smp_processor_id());
}
+EXPORT_SYMBOL_GPL(round_jiffies_up_relative);
-static void internal_add_timer(tvec_base_t *base, struct timer_list *timer)
+static inline void set_running_timer(struct tvec_base *base,
+ struct timer_list *timer)
+{
+#ifdef CONFIG_SMP
+ base->running_timer = timer;
+#endif
+}
+
+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;
list_add_tail(&timer->entry, vec);
}
-typedef struct timer_base_s timer_base_t;
+#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;
+
/*
- * Used by TIMER_INITIALIZER, we can't use per_cpu(tvec_bases)
- * at compile time, and we need timer->base to lock the timer.
+ * fixup_init is called when:
+ * - an active object is initialized
*/
-timer_base_t __init_timer_base
- ____cacheline_aligned_in_smp = { .lock = SPIN_LOCK_UNLOCKED };
-EXPORT_SYMBOL(__init_timer_base);
+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) {
-/***
- * init_timer - initialize a timer.
+ 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_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 = &per_cpu(tvec_bases, raw_smp_processor_id()).t_base;
- timer->magic = TIMER_MAGIC;
+ debug_init(timer);
+ __init_timer(timer, name, key);
}
-EXPORT_SYMBOL(init_timer);
+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_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;
}
/*
- * 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.
*
* 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 struct tvec_base *lock_timer_base(struct timer_list *timer,
unsigned long *flags)
+ __acquires(timer->base->lock)
{
- timer_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);
}
}
-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)
{
- timer_base_t *base;
- tvec_base_t *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);
- check_timer(timer);
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 (base != &new_base->t_base) {
+ if (preferred_cpu >= 0)
+ cpu = preferred_cpu;
+ }
+#endif
+ new_base = per_cpu(tvec_bases, cpu);
+
+ 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,
* 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;
+ timer_set_base(timer, 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_set_base(timer, base);
}
}
timer->expires = expires;
- internal_add_timer(new_base, timer);
- spin_unlock_irqrestore(&new_base->t_base.lock, flags);
+ 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);
-
- check_timer(timer);
-
- spin_lock_irqsave(&base->t_base.lock, flags);
- timer->base = &base->t_base;
- internal_add_timer(base, timer);
- spin_unlock_irqrestore(&base->t_base.lock, flags);
+ return __mod_timer(timer, expires, true, TIMER_NOT_PINNED);
}
+EXPORT_SYMBOL(mod_timer_pending);
-
-/***
+/**
* mod_timer - modify a timer's timeout
* @timer: the timer to be modified
+ * @expires: new timeout in jiffies
*
- * mod_timer is a more efficient way to update the expire field of an
+ * mod_timer() is a more efficient way to update the expire field of an
* active timer (if the timer is inactive it will be activated)
*
* mod_timer(timer, expires) is equivalent to:
*/
int mod_timer(struct timer_list *timer, unsigned long expires)
{
- BUG_ON(!timer->function);
-
- check_timer(timer);
-
/*
* 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.
* @timer: the timer to be deactivated
*
*/
int del_timer(struct timer_list *timer)
{
- timer_base_t *base;
+ struct tvec_base *base;
unsigned long flags;
int ret = 0;
- check_timer(timer);
-
+ 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);
return ret;
}
-
EXPORT_SYMBOL(del_timer);
#ifdef CONFIG_SMP
-/*
+/**
+ * try_to_del_timer_sync - Try to deactivate a timer
+ * @timer: timer do del
+ *
* This function tries to deactivate a timer. Upon successful (ret >= 0)
* exit the timer is not queued and the handler is not running on any CPU.
*
*/
int try_to_del_timer_sync(struct timer_list *timer)
{
- timer_base_t *base;
+ struct tvec_base *base;
unsigned long flags;
int ret = -1;
if (base->running_timer == timer)
goto out;
+ timer_stats_timer_clear_start_info(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:
return ret;
}
+EXPORT_SYMBOL(try_to_del_timer_sync);
-/***
+/**
* del_timer_sync - deactivate a timer and wait for the handler to finish.
* @timer: the timer to be deactivated
*
* the timer it also makes sure the handler has finished executing on other
* CPUs.
*
- * Synchronization rules: callers must prevent restarting of the timer,
+ * Synchronization rules: Callers must prevent restarting of the timer,
* otherwise this function is meaningless. It must not be called from
* interrupt contexts. The caller must not hold locks which would prevent
* completion of the timer's handler. The timer's handler must not call
*/
int del_timer_sync(struct timer_list *timer)
{
- check_timer(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)
return ret;
+ 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 list_head *head, *curr;
+ struct timer_list *timer, *tmp;
+ struct list_head tv_list;
+
+ list_replace_init(tv->vec + index, &tv_list);
- head = tv->vec + index;
- curr = head->next;
/*
- * We are removing _all_ timers from the list, so we don't have to
- * detach them individually, just clear the list afterwards.
+ * We are removing _all_ timers from the list, so we
+ * don't have to detach them individually.
*/
- while (curr != head) {
- struct timer_list *tmp;
-
- tmp = list_entry(curr, struct timer_list, entry);
- BUG_ON(tmp->base != &base->t_base);
- curr = curr->next;
- internal_add_timer(base, tmp);
+ list_for_each_entry_safe(timer, tmp, &tv_list, entry) {
+ BUG_ON(tbase_get_base(timer->base) != base);
+ internal_add_timer(base, timer);
}
- INIT_LIST_HEAD(head);
return index;
}
-/***
+#define INDEX(N) ((base->timer_jiffies >> (TVR_BITS + (N) * TVN_BITS)) & TVN_MASK)
+
+/**
* __run_timers - run all expired timers (if any) on this CPU.
* @base: the timer vector to be processed.
*
* This function cascades all vectors and executes all expired timer
* vectors.
*/
-#define INDEX(N) (base->timer_jiffies >> (TVR_BITS + N * TVN_BITS)) & TVN_MASK
-
-static inline void __run_timers(tvec_base_t *base)
+static inline void __run_timers(struct tvec_base *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 work_list;
struct list_head *head = &work_list;
- int index = base->timer_jiffies & TVR_MASK;
-
+ int index = base->timer_jiffies & TVR_MASK;
+
/*
* Cascade timers:
*/
(!cascade(base, &base->tv3, INDEX(1))) &&
!cascade(base, &base->tv4, INDEX(2)))
cascade(base, &base->tv5, INDEX(3));
- ++base->timer_jiffies;
- list_splice_init(base->tv1.vec + index, &work_list);
+ ++base->timer_jiffies;
+ list_replace_init(base->tv1.vec + index, &work_list);
while (!list_empty(head)) {
void (*fn)(unsigned long);
unsigned long data;
- timer = list_entry(head->next,struct timer_list,entry);
- fn = timer->function;
- data = timer->data;
+ timer = list_first_entry(head, struct timer_list,entry);
+ fn = timer->function;
+ data = timer->data;
+
+ timer_stats_account_timer(timer);
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();
+
+#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);
+
if (preempt_count != preempt_count()) {
- printk(KERN_WARNING "huh, entered %p "
+ printk(KERN_ERR "huh, entered %p "
"with preempt_count %08x, exited"
" with %08x?\n",
fn, preempt_count,
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
+#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 cpus is idle.
- * This functions needs to be called disabled.
+ * is used on S/390 to stop all activity when a CPU is idle.
+ * This function needs to be called with interrupts disabled.
*/
-unsigned long next_timer_interrupt(void)
+static unsigned long __next_timer_interrupt(struct tvec_base *base)
{
- tvec_base_t *base;
- struct list_head *list;
+ 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;
- unsigned long expires;
- tvec_t *varray[4];
- int i, j;
-
- base = &__get_cpu_var(tvec_bases);
- spin_lock(&base->t_base.lock);
- expires = base->timer_jiffies + (LONG_MAX >> 1);
- list = 0;
+ struct tvec *varray[4];
/* Look for timer events in tv1. */
- j = base->timer_jiffies & TVR_MASK;
+ index = slot = timer_jiffies & TVR_MASK;
do {
- list_for_each_entry(nte, base->tv1.vec + j, entry) {
+ list_for_each_entry(nte, base->tv1.vec + slot, entry) {
+ if (tbase_get_deferrable(nte->base))
+ continue;
+
+ found = 1;
expires = nte->expires;
- if (j < (base->timer_jiffies & TVR_MASK))
- list = base->tv2.vec + (INDEX(0));
- goto found;
+ /* Look at the cascade bucket(s)? */
+ if (!index || slot < index)
+ goto cascade;
+ return expires;
}
- j = (j + 1) & TVR_MASK;
- } while (j != (base->timer_jiffies & TVR_MASK));
+ 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 (i = 0; i < 4; i++) {
- j = INDEX(i);
+
+ for (array = 0; array < 4; array++) {
+ struct tvec *varp = varray[array];
+
+ index = slot = timer_jiffies & TVN_MASK;
do {
- if (list_empty(varray[i]->vec + j)) {
- j = (j + 1) & TVN_MASK;
- continue;
- }
- list_for_each_entry(nte, varray[i]->vec + j, entry)
+ list_for_each_entry(nte, varp->vec + slot, entry) {
+ if (tbase_get_deferrable(nte->base))
+ continue;
+
+ found = 1;
if (time_before(nte->expires, expires))
expires = nte->expires;
- if (j < (INDEX(i)) && i < 3)
- list = varray[i + 1]->vec + (INDEX(i + 1));
- goto found;
- } while (j != (INDEX(i)));
- }
-found:
- if (list) {
- /*
- * The search wrapped. We need to look at the next list
- * from next tv element that would cascade into tv element
- * where we found the timer element.
- */
- list_for_each_entry(nte, list, entry) {
- 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;
}
- spin_unlock(&base->t_base.lock);
return expires;
}
-#endif
-
-/******************************************************************/
/*
- * Timekeeping variables
+ * Check, if the next hrtimer event is before the next timer wheel
+ * event:
*/
-unsigned long tick_usec = TICK_USEC; /* USER_HZ period (usec) */
-unsigned long tick_nsec = TICK_NSEC; /* ACTHZ period (nsec) */
-
-/*
- * 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);
+static unsigned long cmp_next_hrtimer_event(unsigned long now,
+ unsigned long expires)
+{
+ ktime_t hr_delta = hrtimer_get_next_event();
+ struct timespec tsdelta;
+ unsigned long delta;
-/* Don't completely fail for HZ > 500. */
-int tickadj = 500/HZ ? : 1; /* microsecs */
+ if (hr_delta.tv64 == KTIME_MAX)
+ return expires;
+ /*
+ * Expired timer available, let it expire in the next tick
+ */
+ if (hr_delta.tv64 <= 0)
+ return now + 1;
-/*
- * phase-lock loop variables
- */
-/* TIME_ERROR prevents overwriting the CMOS clock */
-int time_state = TIME_OK; /* clock synchronization status */
-int time_status = STA_UNSYNC; /* clock status bits */
-long time_offset; /* time adjustment (us) */
-long time_constant = 2; /* pll time constant */
-long time_tolerance = MAXFREQ; /* frequency tolerance (ppm) */
-long time_precision = 1; /* clock precision (us) */
-long time_maxerror = NTP_PHASE_LIMIT; /* maximum error (us) */
-long time_esterror = NTP_PHASE_LIMIT; /* estimated error (us) */
-static long time_phase; /* phase offset (scaled us) */
-long time_freq = (((NSEC_PER_SEC + HZ/2) % HZ - HZ/2) << SHIFT_USEC) / NSEC_PER_USEC;
- /* frequency offset (scaled ppm)*/
-static long time_adj; /* tick adjust (scaled 1 / HZ) */
-long time_reftime; /* time at last adjustment (s) */
-long time_adjust;
-long time_next_adjust;
+ tsdelta = ktime_to_timespec(hr_delta);
+ delta = timespec_to_jiffies(&tsdelta);
-/*
- * this routine handles the overflow of the microsecond field
- *
- * The tricky bits of code to handle the accurate clock support
- * were provided by Dave Mills (Mills@UDEL.EDU) of NTP fame.
- * They were originally developed for SUN and DEC kernels.
- * All the kudos should go to Dave for this stuff.
- *
- */
-static void second_overflow(void)
-{
- long ltemp;
-
- /* Bump the maxerror field */
- time_maxerror += time_tolerance >> SHIFT_USEC;
- if ( time_maxerror > NTP_PHASE_LIMIT ) {
- time_maxerror = NTP_PHASE_LIMIT;
- time_status |= STA_UNSYNC;
- }
-
- /*
- * Leap second processing. If in leap-insert state at
- * the end of the day, the system clock is set back one
- * second; if in leap-delete state, the system clock is
- * set ahead one second. The microtime() routine or
- * external clock driver will insure that reported time
- * is always monotonic. The ugly divides should be
- * replaced.
- */
- switch (time_state) {
-
- case TIME_OK:
- if (time_status & STA_INS)
- time_state = TIME_INS;
- else if (time_status & STA_DEL)
- time_state = TIME_DEL;
- break;
-
- case TIME_INS:
- if (xtime.tv_sec % 86400 == 0) {
- xtime.tv_sec--;
- wall_to_monotonic.tv_sec++;
- /* The timer interpolator will make time change gradually instead
- * of an immediate jump by one second.
- */
- time_interpolator_update(-NSEC_PER_SEC);
- time_state = TIME_OOP;
- clock_was_set();
- printk(KERN_NOTICE "Clock: inserting leap second 23:59:60 UTC\n");
- }
- break;
-
- case TIME_DEL:
- if ((xtime.tv_sec + 1) % 86400 == 0) {
- xtime.tv_sec++;
- wall_to_monotonic.tv_sec--;
- /* Use of time interpolator for a gradual change of time */
- time_interpolator_update(NSEC_PER_SEC);
- time_state = TIME_WAIT;
- clock_was_set();
- printk(KERN_NOTICE "Clock: deleting leap second 23:59:59 UTC\n");
- }
- break;
-
- case TIME_OOP:
- time_state = TIME_WAIT;
- break;
-
- case TIME_WAIT:
- if (!(time_status & (STA_INS | STA_DEL)))
- time_state = TIME_OK;
- }
-
- /*
- * Compute the phase adjustment for the next second. In
- * PLL mode, the offset is reduced by a fixed factor
- * times the time constant. In FLL mode the offset is
- * used directly. In either mode, the maximum phase
- * adjustment for each second is clamped so as to spread
- * the adjustment over not more than the number of
- * seconds between updates.
- */
- if (time_offset < 0) {
- ltemp = -time_offset;
- if (!(time_status & STA_FLL))
- ltemp >>= SHIFT_KG + time_constant;
- if (ltemp > (MAXPHASE / MINSEC) << SHIFT_UPDATE)
- ltemp = (MAXPHASE / MINSEC) << SHIFT_UPDATE;
- time_offset += ltemp;
- time_adj = -ltemp << (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE);
- } else {
- ltemp = time_offset;
- if (!(time_status & STA_FLL))
- ltemp >>= SHIFT_KG + time_constant;
- if (ltemp > (MAXPHASE / MINSEC) << SHIFT_UPDATE)
- ltemp = (MAXPHASE / MINSEC) << SHIFT_UPDATE;
- time_offset -= ltemp;
- time_adj = ltemp << (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE);
- }
-
- /*
- * 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.
- */
- 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;
- if (ltemp < 0)
- time_adj -= -ltemp >>
- (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE);
- else
- time_adj += ltemp >>
- (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE);
-
-#if HZ == 100
- /* Compensate for (HZ==100) != (1 << SHIFT_HZ).
- * Add 25% and 3.125% to get 128.125; => only 0.125% error (p. 14)
- */
- if (time_adj < 0)
- time_adj -= (-time_adj >> 2) + (-time_adj >> 5);
- else
- time_adj += (time_adj >> 2) + (time_adj >> 5);
-#endif
-#if HZ == 1000
- /* Compensate for (HZ==1000) != (1 << SHIFT_HZ).
- * Add 1.5625% and 0.78125% to get 1023.4375; => only 0.05% error (p. 14)
- */
- if (time_adj < 0)
- time_adj -= (-time_adj >> 6) + (-time_adj >> 7);
- else
- time_adj += (time_adj >> 6) + (time_adj >> 7);
-#endif
-}
-
-/* in the NTP reference this is called "hardclock()" */
-static void update_wall_time_one_tick(void)
-{
- long time_adjust_step, delta_nsec;
-
- if ( (time_adjust_step = time_adjust) != 0 ) {
- /* We are doing an adjtime thing.
- *
- * Prepare time_adjust_step to be within bounds.
- * Note that a positive time_adjust means we want the clock
- * to run faster.
- *
- * Limit the amount of the step to be in the range
- * -tickadj .. +tickadj
- */
- if (time_adjust > tickadj)
- time_adjust_step = tickadj;
- else if (time_adjust < -tickadj)
- time_adjust_step = -tickadj;
-
- /* Reduce by this step the amount of time left */
- time_adjust -= time_adjust_step;
- }
- delta_nsec = tick_nsec + time_adjust_step * 1000;
/*
- * Advance the phase, once it gets to one microsecond, then
- * advance the tick more.
+ * Limit the delta to the max value, which is checked in
+ * tick_nohz_stop_sched_tick():
*/
- time_phase += time_adj;
- if (time_phase <= -FINENSEC) {
- long ltemp = -time_phase >> (SHIFT_SCALE - 10);
- time_phase += ltemp << (SHIFT_SCALE - 10);
- delta_nsec -= ltemp;
- }
- else if (time_phase >= FINENSEC) {
- long ltemp = time_phase >> (SHIFT_SCALE - 10);
- time_phase -= ltemp << (SHIFT_SCALE - 10);
- delta_nsec += ltemp;
- }
- xtime.tv_nsec += delta_nsec;
- time_interpolator_update(delta_nsec);
+ if (delta > NEXT_TIMER_MAX_DELTA)
+ delta = NEXT_TIMER_MAX_DELTA;
- /* Changes by adjtime() do not take effect till next tick. */
- if (time_next_adjust != 0) {
- time_adjust = time_next_adjust;
- time_next_adjust = 0;
- }
+ /*
+ * 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;
}
-/*
- * Using a loop looks inefficient, but "ticks" is
- * usually just one (we shouldn't be losing ticks,
- * we're doing this this way mainly for interrupt
- * latency reasons, not because we think we'll
- * have lots of lost timer ticks
+/**
+ * get_next_timer_interrupt - return the jiffy of the next pending timer
+ * @now: current time (in jiffies)
*/
-static void update_wall_time(unsigned long ticks)
+unsigned long get_next_timer_interrupt(unsigned long now)
{
- do {
- ticks--;
- update_wall_time_one_tick();
- if (xtime.tv_nsec >= 1000000000) {
- xtime.tv_nsec -= 1000000000;
- xtime.tv_sec++;
- second_overflow();
- }
- } while (ticks);
+ struct tvec_base *base = __get_cpu_var(tvec_bases);
+ unsigned long expires;
+
+ 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);
+
+ if (time_before_eq(expires, now))
+ return now;
+
+ 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)
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();
+ perf_event_do_pending();
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_running() + nr_uninterruptible()) * FIXED_1;
+ run_posix_cpu_timers(p);
}
/*
- * 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 (count < 0) {
- count += LOAD_FREQ;
- active_tasks = count_active_tasks();
- CALC_LOAD(avenrun[0], EXP_1, active_tasks);
- CALC_LOAD(avenrun[1], EXP_5, active_tasks);
- CALC_LOAD(avenrun[2], EXP_15, active_tasks);
- }
-}
-
-/* jiffies at the most recent update of wall time */
-unsigned long wall_jiffies = INITIAL_JIFFIES;
-
-/*
- * This read-write spinlock protects us from races in SMP while
- * playing with xtime and avenrun.
- */
-#ifndef ARCH_HAVE_XTIME_LOCK
-seqlock_t xtime_lock __cacheline_aligned_in_smp = SEQLOCK_UNLOCKED;
-
-EXPORT_SYMBOL(xtime_lock);
-#endif
-
-/*
* 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);
+
+ hrtimer_run_pending();
if (time_after_eq(jiffies, base->timer_jiffies))
__run_timers(base);
*/
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(void)
-{
- unsigned long ticks;
-
- ticks = jiffies - wall_jiffies;
- if (ticks) {
- wall_jiffies += ticks;
- update_wall_time(ticks);
- }
- 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...
*/
-void do_timer(struct pt_regs *regs)
+void do_timer(unsigned long ticks)
{
- jiffies_64++;
- update_times();
+ jiffies_64 += ticks;
+ update_wall_time();
+ calc_global_load();
}
#ifdef __ARCH_WANT_SYS_ALARM
* 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)
{
- 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
*
* 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);
}
/*
- * Accessing ->group_leader->real_parent is not SMP-safe, it could
- * change from under us. However, rather than getting any lock
- * we can use an optimistic algorithm: get the parent
- * pid, and go back and check that the parent is still
- * the same. If it has changed (which is extremely unlikely
- * indeed), we just try again..
- *
- * NOTE! This depends on the fact that even if we _do_
- * get an old value of "parent", we can happily dereference
- * the pointer (it was and remains a dereferencable kernel pointer
- * no matter what): we just can't necessarily trust the result
- * until we know that the parent pointer is valid.
- *
- * NOTE2: ->group_leader never changes from under us.
+ * Accessing ->real_parent is not SMP-safe, it could
+ * change from under us. However, we can use a stale
+ * 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;
- struct task_struct *me = current;
- struct task_struct *parent;
- parent = me->group_leader->real_parent;
- for (;;) {
- pid = parent->tgid;
-#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
-{
- struct task_struct *old = parent;
+ rcu_read_lock();
+ pid = task_tgid_vnr(current->real_parent);
+ rcu_read_unlock();
- /*
- * Make sure we read the pid before re-reading the
- * parent pointer:
- */
- smp_rmb();
- parent = me->group_leader->real_parent;
- if (old != parent)
- continue;
-}
-#endif
- break;
- }
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
static void process_timeout(unsigned long __data)
{
- wake_up_process((task_t *)__data);
+ wake_up_process((struct task_struct *)__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;
* should never happens anyway). You just have the printk()
* that will tell you if something is gone wrong and where.
*/
- if (timeout < 0)
- {
+ if (timeout < 0) {
printk(KERN_ERR "schedule_timeout: wrong timeout "
- "value %lx from %p\n", timeout,
- __builtin_return_address(0));
+ "value %lx\n", timeout);
+ dump_stack();
current->state = TASK_RUNNING;
goto out;
}
expire = timeout + jiffies;
- init_timer(&timer);
- timer.expires = expire;
- timer.data = (unsigned long) current;
- timer.function = process_timeout;
-
- add_timer(&timer);
+ 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:
return timeout < 0 ? 0 : timeout;
}
-
EXPORT_SYMBOL(schedule_timeout);
-/* Thread ID - the internal kernel "pid" */
-asmlinkage long sys_gettid(void)
+/*
+ * We can use __set_current_state() here because schedule_timeout() calls
+ * schedule() unconditionally.
+ */
+signed long __sched schedule_timeout_interruptible(signed long timeout)
{
- return current->pid;
+ __set_current_state(TASK_INTERRUPTIBLE);
+ return schedule_timeout(timeout);
}
+EXPORT_SYMBOL(schedule_timeout_interruptible);
-static long __sched nanosleep_restart(struct restart_block *restart)
+signed long __sched schedule_timeout_killable(signed long timeout)
{
- unsigned long expire = restart->arg0, now = jiffies;
- struct timespec __user *rmtp = (struct timespec __user *) restart->arg1;
- long ret;
-
- /* Did it expire while we handled signals? */
- if (!time_after(expire, now))
- return 0;
-
- current->state = TASK_INTERRUPTIBLE;
- expire = schedule_timeout(expire - now);
-
- ret = 0;
- if (expire) {
- struct timespec t;
- jiffies_to_timespec(expire, &t);
-
- ret = -ERESTART_RESTARTBLOCK;
- if (rmtp && copy_to_user(rmtp, &t, sizeof(t)))
- ret = -EFAULT;
- /* The 'restart' block is already filled in */
- }
- return ret;
+ __set_current_state(TASK_KILLABLE);
+ return schedule_timeout(timeout);
}
+EXPORT_SYMBOL(schedule_timeout_killable);
-asmlinkage long sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp)
+signed long __sched schedule_timeout_uninterruptible(signed long timeout)
{
- struct timespec t;
- unsigned long expire;
- long ret;
-
- if (copy_from_user(&t, rqtp, sizeof(t)))
- return -EFAULT;
-
- if ((t.tv_nsec >= 1000000000L) || (t.tv_nsec < 0) || (t.tv_sec < 0))
- return -EINVAL;
-
- expire = timespec_to_jiffies(&t) + (t.tv_sec || t.tv_nsec);
- current->state = TASK_INTERRUPTIBLE;
- expire = schedule_timeout(expire);
+ __set_current_state(TASK_UNINTERRUPTIBLE);
+ return schedule_timeout(timeout);
+}
+EXPORT_SYMBOL(schedule_timeout_uninterruptible);
- ret = 0;
- if (expire) {
- struct restart_block *restart;
- jiffies_to_timespec(expire, &t);
- if (rmtp && copy_to_user(rmtp, &t, sizeof(t)))
- return -EFAULT;
-
- restart = ¤t_thread_info()->restart_block;
- restart->fn = nanosleep_restart;
- restart->arg0 = jiffies + expire;
- restart->arg1 = (unsigned long) rmtp;
- ret = -ERESTART_RESTARTBLOCK;
- }
- return ret;
+/* Thread ID - the internal kernel "pid" */
+SYSCALL_DEFINE0(gettid)
+{
+ return task_pid_vnr(current);
}
-/*
- * sys_sysinfo - fill in sysinfo struct
- */
-asmlinkage long sys_sysinfo(struct sysinfo __user *info)
+/**
+ * do_sysinfo - fill in sysinfo struct
+ * @info: pointer to buffer to fill
+ */
+int do_sysinfo(struct sysinfo *info)
{
- struct sysinfo val;
unsigned long mem_total, sav_total;
unsigned int mem_unit, bitcount;
- unsigned long seq;
+ struct timespec tp;
- memset((char *)&val, 0, sizeof(struct sysinfo));
+ memset(info, 0, sizeof(struct sysinfo));
- do {
- struct timespec tp;
- seq = read_seqbegin(&xtime_lock);
+ ktime_get_ts(&tp);
+ monotonic_to_bootbased(&tp);
+ info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
- /*
- * 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++;
- }
- val.uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
+ get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
- val.loads[0] = avenrun[0] << (SI_LOAD_SHIFT - FSHIFT);
- val.loads[1] = avenrun[1] << (SI_LOAD_SHIFT - FSHIFT);
- val.loads[2] = avenrun[2] << (SI_LOAD_SHIFT - FSHIFT);
+ info->procs = nr_threads;
- val.procs = nr_threads;
- } while (read_seqretry(&xtime_lock, seq));
-
- si_meminfo(&val);
- si_swapinfo(&val);
+ si_meminfo(info);
+ si_swapinfo(info);
/*
* If the sum of all the available memory (i.e. ram + swap)
* -Erik Andersen <andersee@debian.org>
*/
- mem_total = val.totalram + val.totalswap;
- if (mem_total < val.totalram || mem_total < val.totalswap)
+ mem_total = info->totalram + info->totalswap;
+ if (mem_total < info->totalram || mem_total < info->totalswap)
goto out;
bitcount = 0;
- mem_unit = val.mem_unit;
+ mem_unit = info->mem_unit;
while (mem_unit > 1) {
bitcount++;
mem_unit >>= 1;
/*
* If mem_total did not overflow, multiply all memory values by
- * val.mem_unit and set it to 1. This leaves things compatible
+ * info->mem_unit and set it to 1. This leaves things compatible
* with 2.2.x, and also retains compatibility with earlier 2.4.x
* kernels...
*/
- val.mem_unit = 1;
- val.totalram <<= bitcount;
- val.freeram <<= bitcount;
- val.sharedram <<= bitcount;
- val.bufferram <<= bitcount;
- val.totalswap <<= bitcount;
- val.freeswap <<= bitcount;
- val.totalhigh <<= bitcount;
- val.freehigh <<= bitcount;
+ info->mem_unit = 1;
+ info->totalram <<= bitcount;
+ info->freeram <<= bitcount;
+ info->sharedram <<= bitcount;
+ info->bufferram <<= bitcount;
+ info->totalswap <<= bitcount;
+ info->freeswap <<= bitcount;
+ info->totalhigh <<= bitcount;
+ info->freehigh <<= bitcount;
+
+out:
+ return 0;
+}
+
+SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
+{
+ struct sysinfo val;
+
+ do_sysinfo(&val);
- out:
if (copy_to_user(info, &val, sizeof(struct sysinfo)))
return -EFAULT;
return 0;
}
-static void __devinit init_timers_cpu(int cpu)
+static int __cpuinit init_timers_cpu(int cpu)
{
int j;
- tvec_base_t *base;
+ struct tvec_base *base;
+ static char __cpuinitdata tvec_base_done[NR_CPUS];
+
+ if (!tvec_base_done[cpu]) {
+ static char boot_done;
+
+ if (boot_done) {
+ /*
+ * The APs use this path later in boot
+ */
+ base = kmalloc_node(sizeof(*base),
+ GFP_KERNEL | __GFP_ZERO,
+ cpu_to_node(cpu));
+ if (!base)
+ return -ENOMEM;
+
+ /* 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 {
+ /*
+ * 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;
+ }
+ tvec_base_done[cpu] = 1;
+ } else {
+ base = per_cpu(tvec_bases, cpu);
+ }
+
+ spin_lock_init(&base->lock);
- base = &per_cpu(tvec_bases, cpu);
- spin_lock_init(&base->t_base.lock);
for (j = 0; j < TVN_SIZE; j++) {
INIT_LIST_HEAD(base->tv5.vec + j);
INIT_LIST_HEAD(base->tv4.vec + j);
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->t_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);
+ old_base = per_cpu(tvec_bases, cpu);
+ new_base = get_cpu_var(tvec_bases);
+ /*
+ * 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);
- local_irq_disable();
- spin_lock(&new_base->t_base.lock);
- spin_lock(&old_base->t_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++) {
migrate_timer_list(new_base, old_base->tv5.vec + i);
}
- spin_unlock(&old_base->t_base.lock);
- spin_unlock(&new_base->t_base.lock);
- local_irq_enable();
+ spin_unlock(&old_base->lock);
+ spin_unlock_irq(&new_base->lock);
put_cpu_var(tvec_bases);
}
#endif /* CONFIG_HOTPLUG_CPU */
-static int __devinit timer_cpu_notify(struct notifier_block *self,
+static int __cpuinit timer_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
long cpu = (long)hcpu;
switch(action) {
case CPU_UP_PREPARE:
- init_timers_cpu(cpu);
+ 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
return NOTIFY_OK;
}
-static struct notifier_block __devinitdata timers_nb = {
+static struct notifier_block __cpuinitdata timers_nb = {
.notifier_call = timer_cpu_notify,
};
void __init init_timers(void)
{
- timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE,
+ int err = timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE,
(void *)(long)smp_processor_id());
- register_cpu_notifier(&timers_nb);
- open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL);
-}
-
-#ifdef CONFIG_TIME_INTERPOLATION
-struct time_interpolator *time_interpolator;
-static struct time_interpolator *time_interpolator_list;
-static DEFINE_SPINLOCK(time_interpolator_lock);
+ init_timer_stats();
-static inline u64 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((void __iomem *) time_interpolator->addr);
-
- case TIME_SOURCE_MMIO32 :
- return readl((void __iomem *) time_interpolator->addr);
-
- default: return get_cycles();
- }
-}
-
-static inline u64 time_interpolator_get_counter(void)
-{
- unsigned int src = time_interpolator->source;
-
- if (time_interpolator->jitter)
- {
- u64 lcycle;
- u64 now;
-
- do {
- lcycle = time_interpolator->last_cycle;
- now = time_interpolator_get_cycles(src);
- if (lcycle && time_after(lcycle, now))
- return lcycle;
- /* 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();
-}
-
-#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(), time_interpolator);
-}
-
-#define INTERPOLATOR_ADJUST 65536
-#define INTERPOLATOR_MAX_SKIP 10*INTERPOLATOR_ADJUST
-
-static 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();
- 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 */
- if (ti->frequency == 0 || ti->mask == 0)
- BUG();
-
- 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);
+ BUG_ON(err == NOTIFY_BAD);
+ register_cpu_notifier(&timers_nb);
+ open_softirq(TIMER_SOFTIRQ, run_timer_softirq);
}
-#endif /* CONFIG_TIME_INTERPOLATION */
/**
* msleep - sleep safely even with waitqueue interruptions
{
unsigned long timeout = msecs_to_jiffies(msecs) + 1;
- while (timeout) {
- set_current_state(TASK_UNINTERRUPTIBLE);
- timeout = schedule_timeout(timeout);
- }
+ while (timeout)
+ timeout = schedule_timeout_uninterruptible(timeout);
}
EXPORT_SYMBOL(msleep);
{
unsigned long timeout = msecs_to_jiffies(msecs) + 1;
- while (timeout && !signal_pending(current)) {
- set_current_state(TASK_INTERRUPTIBLE);
- timeout = schedule_timeout(timeout);
- }
+ while (timeout && !signal_pending(current))
+ timeout = schedule_timeout_interruptible(timeout);
return jiffies_to_msecs(timeout);
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff