#include <asm/timex.h>
#include <asm/io.h>
+#include "tick-internal.h"
+
#define CREATE_TRACE_POINTS
#include <trace/events/timer.h>
#define MAX_TVAL ((unsigned long)((1ULL << (TVR_BITS + 4*TVN_BITS)) - 1))
struct tvec {
- struct list_head vec[TVN_SIZE];
+ struct hlist_head vec[TVN_SIZE];
};
struct tvec_root {
- struct list_head vec[TVR_SIZE];
+ struct hlist_head vec[TVR_SIZE];
};
struct tvec_base {
unsigned long active_timers;
unsigned long all_timers;
int cpu;
+ bool migration_enabled;
+ bool nohz_active;
struct tvec_root tv1;
struct tvec tv2;
struct tvec tv3;
struct tvec tv5;
} ____cacheline_aligned;
-/*
- * __TIMER_INITIALIZER() needs to set ->base to a valid pointer (because we've
- * made NULL special, hint: lock_timer_base()) and we cannot get a compile time
- * pointer to per-cpu entries because we don't know where we'll map the section,
- * even for the boot cpu.
- *
- * And so we use boot_tvec_bases for boot CPU and per-cpu __tvec_bases for the
- * rest of them.
- */
-struct tvec_base boot_tvec_bases;
-EXPORT_SYMBOL(boot_tvec_bases);
-static DEFINE_PER_CPU(struct tvec_base *, tvec_bases) = &boot_tvec_bases;
+static DEFINE_PER_CPU(struct tvec_base, tvec_bases);
+
+#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
+unsigned int sysctl_timer_migration = 1;
-/* Functions below help us manage 'deferrable' flag */
-static inline unsigned int tbase_get_deferrable(struct tvec_base *base)
+void timers_update_migration(bool update_nohz)
{
- return ((unsigned int)(unsigned long)base & TIMER_DEFERRABLE);
+ bool on = sysctl_timer_migration && tick_nohz_active;
+ unsigned int cpu;
+
+ /* Avoid the loop, if nothing to update */
+ if (this_cpu_read(tvec_bases.migration_enabled) == on)
+ return;
+
+ for_each_possible_cpu(cpu) {
+ per_cpu(tvec_bases.migration_enabled, cpu) = on;
+ per_cpu(hrtimer_bases.migration_enabled, cpu) = on;
+ if (!update_nohz)
+ continue;
+ per_cpu(tvec_bases.nohz_active, cpu) = true;
+ per_cpu(hrtimer_bases.nohz_active, cpu) = true;
+ }
}
-static inline unsigned int tbase_get_irqsafe(struct tvec_base *base)
+int timer_migration_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp,
+ loff_t *ppos)
{
- return ((unsigned int)(unsigned long)base & TIMER_IRQSAFE);
+ static DEFINE_MUTEX(mutex);
+ int ret;
+
+ mutex_lock(&mutex);
+ ret = proc_dointvec(table, write, buffer, lenp, ppos);
+ if (!ret && write)
+ timers_update_migration(false);
+ mutex_unlock(&mutex);
+ return ret;
}
-static inline struct tvec_base *tbase_get_base(struct tvec_base *base)
+static inline struct tvec_base *get_target_base(struct tvec_base *base,
+ int pinned)
{
- return ((struct tvec_base *)((unsigned long)base & ~TIMER_FLAG_MASK));
+ if (pinned || !base->migration_enabled)
+ return this_cpu_ptr(&tvec_bases);
+ return per_cpu_ptr(&tvec_bases, get_nohz_timer_target());
}
-
-static inline void
-timer_set_base(struct timer_list *timer, struct tvec_base *new_base)
+#else
+static inline struct tvec_base *get_target_base(struct tvec_base *base,
+ int pinned)
{
- unsigned long flags = (unsigned long)timer->base & TIMER_FLAG_MASK;
-
- timer->base = (struct tvec_base *)((unsigned long)(new_base) | flags);
+ return this_cpu_ptr(&tvec_bases);
}
+#endif
static unsigned long round_jiffies_common(unsigned long j, int cpu,
bool force_up)
}
EXPORT_SYMBOL_GPL(set_timer_slack);
-/*
- * If the list is empty, catch up ->timer_jiffies to the current time.
- * The caller must hold the tvec_base lock. Returns true if the list
- * was empty and therefore ->timer_jiffies was updated.
- */
-static bool catchup_timer_jiffies(struct tvec_base *base)
-{
- if (!base->all_timers) {
- base->timer_jiffies = jiffies;
- return true;
- }
- return false;
-}
-
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;
- struct list_head *vec;
+ struct hlist_head *vec;
if (idx < TVR_SIZE) {
int i = expires & TVR_MASK;
i = (expires >> (TVR_BITS + 3 * TVN_BITS)) & TVN_MASK;
vec = base->tv5.vec + i;
}
- /*
- * Timers are FIFO:
- */
- list_add_tail(&timer->entry, vec);
+
+ hlist_add_head(&timer->entry, vec);
}
static void internal_add_timer(struct tvec_base *base, struct timer_list *timer)
{
- (void)catchup_timer_jiffies(base);
+ /* Advance base->jiffies, if the base is empty */
+ if (!base->all_timers++)
+ base->timer_jiffies = jiffies;
+
__internal_add_timer(base, timer);
/*
* Update base->active_timers and base->next_timer
*/
- if (!tbase_get_deferrable(timer->base)) {
+ if (!(timer->flags & TIMER_DEFERRABLE)) {
if (!base->active_timers++ ||
time_before(timer->expires, base->next_timer))
base->next_timer = timer->expires;
}
- base->all_timers++;
/*
* Check whether the other CPU is in dynticks mode and needs
* require special care against races with idle_cpu(), lets deal
* with that later.
*/
- if (!tbase_get_deferrable(base) || tick_nohz_full_cpu(base->cpu))
- wake_up_nohz_cpu(base->cpu);
+ if (base->nohz_active) {
+ if (!(timer->flags & TIMER_DEFERRABLE) ||
+ tick_nohz_full_cpu(base->cpu))
+ wake_up_nohz_cpu(base->cpu);
+ }
}
#ifdef CONFIG_TIMER_STATS
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);
+ timer->function, timer->start_comm,
+ timer->flags);
}
#else
* 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) {
+ if (timer->entry.pprev == NULL &&
+ timer->entry.next == TIMER_ENTRY_STATIC) {
debug_object_init(timer, &timer_debug_descr);
debug_object_activate(timer, &timer_debug_descr);
return 0;
switch (state) {
case ODEBUG_STATE_NOTAVAILABLE:
- if (timer->entry.prev == TIMER_ENTRY_STATIC) {
+ if (timer->entry.next == TIMER_ENTRY_STATIC) {
/*
* This is not really a fixup. The timer was
* statically initialized. We just make sure that it
debug_activate(struct timer_list *timer, unsigned long expires)
{
debug_timer_activate(timer);
- trace_timer_start(timer, expires);
+ trace_timer_start(timer, expires, timer->flags);
}
static inline void debug_deactivate(struct timer_list *timer)
static void do_init_timer(struct timer_list *timer, unsigned int flags,
const char *name, struct lock_class_key *key)
{
- struct tvec_base *base = raw_cpu_read(tvec_bases);
-
- timer->entry.next = NULL;
- timer->base = (void *)((unsigned long)base | flags);
+ timer->entry.pprev = NULL;
+ timer->flags = flags | raw_smp_processor_id();
timer->slack = -1;
#ifdef CONFIG_TIMER_STATS
timer->start_site = NULL;
static inline void detach_timer(struct timer_list *timer, bool clear_pending)
{
- struct list_head *entry = &timer->entry;
+ struct hlist_node *entry = &timer->entry;
debug_deactivate(timer);
- __list_del(entry->prev, entry->next);
+ __hlist_del(entry);
if (clear_pending)
- entry->next = NULL;
- entry->prev = LIST_POISON2;
+ entry->pprev = NULL;
+ entry->next = LIST_POISON2;
}
static inline void
detach_expired_timer(struct timer_list *timer, struct tvec_base *base)
{
detach_timer(timer, true);
- if (!tbase_get_deferrable(timer->base))
+ if (!(timer->flags & TIMER_DEFERRABLE))
base->active_timers--;
base->all_timers--;
- (void)catchup_timer_jiffies(base);
}
static int detach_if_pending(struct timer_list *timer, struct tvec_base *base,
return 0;
detach_timer(timer, clear_pending);
- if (!tbase_get_deferrable(timer->base)) {
+ if (!(timer->flags & TIMER_DEFERRABLE)) {
base->active_timers--;
if (timer->expires == base->next_timer)
base->next_timer = base->timer_jiffies;
}
- base->all_timers--;
- (void)catchup_timer_jiffies(base);
+ /* If this was the last timer, advance base->jiffies */
+ if (!--base->all_timers)
+ base->timer_jiffies = jiffies;
return 1;
}
* So __run_timers/migrate_timers can safely modify all timers which could
* be found on ->tvX lists.
*
- * When the timer's base is locked, and the timer removed from list, it is
- * possible to set timer->base = NULL and drop the lock: the timer remains
- * locked.
+ * When the timer's base is locked and removed from the list, the
+ * TIMER_MIGRATING flag is set, FIXME
*/
static struct tvec_base *lock_timer_base(struct timer_list *timer,
unsigned long *flags)
__acquires(timer->base->lock)
{
- struct tvec_base *base;
-
for (;;) {
- struct tvec_base *prelock_base = timer->base;
- base = tbase_get_base(prelock_base);
- if (likely(base != NULL)) {
+ u32 tf = timer->flags;
+ struct tvec_base *base;
+
+ if (!(tf & TIMER_MIGRATING)) {
+ base = per_cpu_ptr(&tvec_bases, tf & TIMER_CPUMASK);
spin_lock_irqsave(&base->lock, *flags);
- if (likely(prelock_base == timer->base))
+ if (timer->flags == tf)
return base;
- /* The timer has migrated to another CPU */
spin_unlock_irqrestore(&base->lock, *flags);
}
cpu_relax();
static inline int
__mod_timer(struct timer_list *timer, unsigned long expires,
- bool pending_only, int pinned)
+ bool pending_only, int pinned)
{
struct tvec_base *base, *new_base;
unsigned long flags;
- int ret = 0 , cpu;
+ int ret = 0;
timer_stats_timer_set_start_info(timer);
BUG_ON(!timer->function);
debug_activate(timer, expires);
- cpu = get_nohz_timer_target(pinned);
- new_base = per_cpu(tvec_bases, cpu);
+ new_base = get_target_base(base, pinned);
if (base != new_base) {
/*
*/
if (likely(base->running_timer != timer)) {
/* See the comment in lock_timer_base() */
- timer_set_base(timer, NULL);
+ timer->flags |= TIMER_MIGRATING;
+
spin_unlock(&base->lock);
base = new_base;
spin_lock(&base->lock);
- timer_set_base(timer, base);
+ timer->flags &= ~TIMER_BASEMASK;
+ timer->flags |= base->cpu;
}
}
*/
void add_timer_on(struct timer_list *timer, int cpu)
{
- struct tvec_base *base = per_cpu(tvec_bases, cpu);
+ struct tvec_base *base = per_cpu_ptr(&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);
+ timer->flags = (timer->flags & ~TIMER_BASEMASK) | cpu;
debug_activate(timer, timer->expires);
internal_add_timer(base, timer);
spin_unlock_irqrestore(&base->lock, flags);
EXPORT_SYMBOL(try_to_del_timer_sync);
#ifdef CONFIG_SMP
-static DEFINE_PER_CPU(struct tvec_base, __tvec_bases);
-
/**
* del_timer_sync - deactivate a timer and wait for the handler to finish.
* @timer: the timer to be deactivated
* don't use it in hardirq context, because it
* could lead to deadlock.
*/
- WARN_ON(in_irq() && !tbase_get_irqsafe(timer->base));
+ WARN_ON(in_irq() && !(timer->flags & TIMER_IRQSAFE));
for (;;) {
int ret = try_to_del_timer_sync(timer);
if (ret >= 0)
static int cascade(struct tvec_base *base, struct tvec *tv, int index)
{
/* cascade all the timers from tv up one level */
- struct timer_list *timer, *tmp;
- struct list_head tv_list;
+ struct timer_list *timer;
+ struct hlist_node *tmp;
+ struct hlist_head tv_list;
- list_replace_init(tv->vec + index, &tv_list);
+ hlist_move_list(tv->vec + index, &tv_list);
/*
* We are removing _all_ timers from the list, so we
* don't have to detach them individually.
*/
- list_for_each_entry_safe(timer, tmp, &tv_list, entry) {
- BUG_ON(tbase_get_base(timer->base) != base);
+ hlist_for_each_entry_safe(timer, tmp, &tv_list, entry) {
/* No accounting, while moving them */
__internal_add_timer(base, timer);
}
struct timer_list *timer;
spin_lock_irq(&base->lock);
- if (catchup_timer_jiffies(base)) {
- spin_unlock_irq(&base->lock);
- return;
- }
+
while (time_after_eq(jiffies, base->timer_jiffies)) {
- struct list_head work_list;
- struct list_head *head = &work_list;
- int index = base->timer_jiffies & TVR_MASK;
+ struct hlist_head work_list;
+ struct hlist_head *head = &work_list;
+ int index;
+
+ if (!base->all_timers) {
+ base->timer_jiffies = jiffies;
+ break;
+ }
+
+ index = base->timer_jiffies & TVR_MASK;
/*
* Cascade timers:
!cascade(base, &base->tv4, INDEX(2)))
cascade(base, &base->tv5, INDEX(3));
++base->timer_jiffies;
- list_replace_init(base->tv1.vec + index, head);
- while (!list_empty(head)) {
+ hlist_move_list(base->tv1.vec + index, head);
+ while (!hlist_empty(head)) {
void (*fn)(unsigned long);
unsigned long data;
bool irqsafe;
- timer = list_first_entry(head, struct timer_list,entry);
+ timer = hlist_entry(head->first, struct timer_list, entry);
fn = timer->function;
data = timer->data;
- irqsafe = tbase_get_irqsafe(timer->base);
+ irqsafe = timer->flags & TIMER_IRQSAFE;
timer_stats_account_timer(timer);
/* Look for timer events in tv1. */
index = slot = timer_jiffies & TVR_MASK;
do {
- list_for_each_entry(nte, base->tv1.vec + slot, entry) {
- if (tbase_get_deferrable(nte->base))
+ hlist_for_each_entry(nte, base->tv1.vec + slot, entry) {
+ if (nte->flags & TIMER_DEFERRABLE)
continue;
found = 1;
index = slot = timer_jiffies & TVN_MASK;
do {
- list_for_each_entry(nte, varp->vec + slot, entry) {
- if (tbase_get_deferrable(nte->base))
+ hlist_for_each_entry(nte, varp->vec + slot, entry) {
+ if (nte->flags & TIMER_DEFERRABLE)
continue;
found = 1;
* Check, if the next hrtimer event is before the next timer wheel
* event:
*/
-static unsigned long cmp_next_hrtimer_event(unsigned long now,
- unsigned long expires)
+static u64 cmp_next_hrtimer_event(u64 basem, u64 expires)
{
- ktime_t hr_delta = hrtimer_get_next_event();
- struct timespec tsdelta;
- unsigned long delta;
-
- if (hr_delta.tv64 == KTIME_MAX)
- return expires;
+ u64 nextevt = hrtimer_get_next_event();
/*
- * Expired timer available, let it expire in the next tick
+ * If high resolution timers are enabled
+ * hrtimer_get_next_event() returns KTIME_MAX.
*/
- if (hr_delta.tv64 <= 0)
- return now + 1;
-
- tsdelta = ktime_to_timespec(hr_delta);
- delta = timespec_to_jiffies(&tsdelta);
+ if (expires <= nextevt)
+ return expires;
/*
- * Limit the delta to the max value, which is checked in
- * tick_nohz_stop_sched_tick():
+ * If the next timer is already expired, return the tick base
+ * time so the tick is fired immediately.
*/
- if (delta > NEXT_TIMER_MAX_DELTA)
- delta = NEXT_TIMER_MAX_DELTA;
+ if (nextevt <= basem)
+ return basem;
/*
- * 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
+ * Round up to the next jiffie. High resolution timers are
+ * off, so the hrtimers are expired in the tick and we need to
+ * make sure that this tick really expires the timer to avoid
+ * a ping pong of the nohz stop code.
+ *
+ * Use DIV_ROUND_UP_ULL to prevent gcc calling __divdi3
*/
- if (delta < 1)
- delta = 1;
- now += delta;
- if (time_before(now, expires))
- return now;
- return expires;
+ return DIV_ROUND_UP_ULL(nextevt, TICK_NSEC) * TICK_NSEC;
}
/**
- * get_next_timer_interrupt - return the jiffy of the next pending timer
- * @now: current time (in jiffies)
+ * get_next_timer_interrupt - return the time (clock mono) of the next timer
+ * @basej: base time jiffies
+ * @basem: base time clock monotonic
+ *
+ * Returns the tick aligned clock monotonic time of the next pending
+ * timer or KTIME_MAX if no timer is pending.
*/
-unsigned long get_next_timer_interrupt(unsigned long now)
+u64 get_next_timer_interrupt(unsigned long basej, u64 basem)
{
- struct tvec_base *base = __this_cpu_read(tvec_bases);
- unsigned long expires = now + NEXT_TIMER_MAX_DELTA;
+ struct tvec_base *base = this_cpu_ptr(&tvec_bases);
+ u64 expires = KTIME_MAX;
+ unsigned long nextevt;
/*
* Pretend that there is no timer pending if the cpu is offline.
if (base->active_timers) {
if (time_before_eq(base->next_timer, base->timer_jiffies))
base->next_timer = __next_timer_interrupt(base);
- expires = base->next_timer;
+ nextevt = base->next_timer;
+ if (time_before_eq(nextevt, basej))
+ expires = basem;
+ else
+ expires = basem + (nextevt - basej) * TICK_NSEC;
}
spin_unlock(&base->lock);
- if (time_before_eq(expires, now))
- return now;
-
- return cmp_next_hrtimer_event(now, expires);
+ return cmp_next_hrtimer_event(basem, expires);
}
#endif
*/
static void run_timer_softirq(struct softirq_action *h)
{
- struct tvec_base *base = __this_cpu_read(tvec_bases);
-
- hrtimer_run_pending();
+ struct tvec_base *base = this_cpu_ptr(&tvec_bases);
if (time_after_eq(jiffies, base->timer_jiffies))
__run_timers(base);
EXPORT_SYMBOL(schedule_timeout_uninterruptible);
#ifdef CONFIG_HOTPLUG_CPU
-static void migrate_timer_list(struct tvec_base *new_base, struct list_head *head)
+static void migrate_timer_list(struct tvec_base *new_base, struct hlist_head *head)
{
struct timer_list *timer;
+ int cpu = new_base->cpu;
- while (!list_empty(head)) {
- timer = list_first_entry(head, struct timer_list, entry);
+ while (!hlist_empty(head)) {
+ timer = hlist_entry(head->first, struct timer_list, entry);
/* We ignore the accounting on the dying cpu */
detach_timer(timer, false);
- timer_set_base(timer, new_base);
+ timer->flags = (timer->flags & ~TIMER_BASEMASK) | cpu;
internal_add_timer(new_base, timer);
}
}
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_ptr(&tvec_bases, cpu);
+ new_base = this_cpu_ptr(&tvec_bases);
/*
* The caller is globally serialized and nobody else
* takes two locks at once, deadlock is not possible.
spin_unlock(&old_base->lock);
spin_unlock_irq(&new_base->lock);
- put_cpu_var(tvec_bases);
}
static int timer_cpu_notify(struct notifier_block *self,
static inline void timer_register_cpu_notifier(void) { }
#endif /* CONFIG_HOTPLUG_CPU */
-static void __init init_timer_cpu(struct tvec_base *base, int cpu)
+static void __init init_timer_cpu(int cpu)
{
- int j;
-
- BUG_ON(base != tbase_get_base(base));
+ struct tvec_base *base = per_cpu_ptr(&tvec_bases, cpu);
base->cpu = cpu;
- 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);
- INIT_LIST_HEAD(base->tv3.vec + j);
- INIT_LIST_HEAD(base->tv2.vec + j);
- }
- for (j = 0; j < TVR_SIZE; j++)
- INIT_LIST_HEAD(base->tv1.vec + j);
-
base->timer_jiffies = jiffies;
base->next_timer = base->timer_jiffies;
}
static void __init init_timer_cpus(void)
{
- struct tvec_base *base;
- int local_cpu = smp_processor_id();
int cpu;
- for_each_possible_cpu(cpu) {
- if (cpu == local_cpu)
- base = &boot_tvec_bases;
-#ifdef CONFIG_SMP
- else
- base = per_cpu_ptr(&__tvec_bases, cpu);
-#endif
-
- init_timer_cpu(base, cpu);
- }
+ for_each_possible_cpu(cpu)
+ init_timer_cpu(cpu);
}
void __init init_timers(void)
{
- /* ensure there are enough low bits for flags in timer->base pointer */
- BUILD_BUG_ON(__alignof__(struct tvec_base) & TIMER_FLAG_MASK);
-
init_timer_cpus();
init_timer_stats();
timer_register_cpu_notifier();
EXPORT_SYMBOL(msleep_interruptible);
-static int __sched do_usleep_range(unsigned long min, unsigned long max)
+static void __sched do_usleep_range(unsigned long min, unsigned long max)
{
ktime_t kmin;
unsigned long delta;
kmin = ktime_set(0, min * NSEC_PER_USEC);
delta = (max - min) * NSEC_PER_USEC;
- return schedule_hrtimeout_range(&kmin, delta, HRTIMER_MODE_REL);
+ schedule_hrtimeout_range(&kmin, delta, HRTIMER_MODE_REL);
}
/**
* @min: Minimum time in usecs to sleep
* @max: Maximum time in usecs to sleep
*/
-void usleep_range(unsigned long min, unsigned long max)
+void __sched usleep_range(unsigned long min, unsigned long max)
{
__set_current_state(TASK_UNINTERRUPTIBLE);
do_usleep_range(min, max);
projects / linux-2.6-block.git / blobdiff