#include <linux/thread_info.h>
#include <linux/time.h>
#include <linux/jiffies.h>
+#include <linux/posix-timers.h>
#include <linux/cpu.h>
#include <linux/syscalls.h>
+#include <linux/delay.h>
#include <linux/vs_cvirt.h>
#include <linux/vserver/sched.h>
#define time_interpolator_update(x)
#endif
+u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES;
+
+EXPORT_SYMBOL(jiffies_64);
+
/*
* per-CPU timer vector definitions:
*/
-#define TVN_BITS 6
-#define TVR_BITS 8
+
+#define TVN_BITS (CONFIG_BASE_SMALL ? 4 : 6)
+#define TVR_BITS (CONFIG_BASE_SMALL ? 6 : 8)
#define TVN_SIZE (1 << TVN_BITS)
#define TVR_SIZE (1 << TVR_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 list_head vec[TVN_SIZE];
} tvec_t;
} tvec_root_t;
struct tvec_t_base_s {
- spinlock_t lock;
+ struct timer_base_s t_base;
unsigned long timer_jiffies;
- struct timer_list *running_timer;
tvec_root_t tv1;
tvec_t tv2;
tvec_t tv3;
} ____cacheline_aligned_in_smp;
typedef struct tvec_t_base_s tvec_base_t;
+static DEFINE_PER_CPU(tvec_base_t, tvec_bases);
static inline void set_running_timer(tvec_base_t *base,
struct timer_list *timer)
{
#ifdef CONFIG_SMP
- base->running_timer = timer;
+ base->t_base.running_timer = timer;
#endif
}
-/* Fake initialization */
-static DEFINE_PER_CPU(tvec_base_t, tvec_bases) = { SPIN_LOCK_UNLOCKED };
-
-static void check_timer_failed(struct timer_list *timer)
-{
- 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();
- }
- /*
- * Now fix it up
- */
- spin_lock_init(&timer->lock);
- timer->magic = TIMER_MAGIC;
-}
-
-static inline void check_timer(struct timer_list *timer)
-{
- if (timer->magic != TIMER_MAGIC)
- check_timer_failed(timer);
-}
-
-
static void internal_add_timer(tvec_base_t *base, struct timer_list *timer)
{
unsigned long expires = timer->expires;
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
+ *
+ * init_timer() must be done to a timer prior calling *any* of the
+ * other timer functions.
+ */
+void fastcall init_timer(struct timer_list *timer)
+{
+ timer->entry.next = NULL;
+ timer->base = &per_cpu(tvec_bases, raw_smp_processor_id()).t_base;
+}
+EXPORT_SYMBOL(init_timer);
+
+static inline void detach_timer(struct timer_list *timer,
+ int clear_pending)
+{
+ struct list_head *entry = &timer->entry;
+
+ __list_del(entry->prev, entry->next);
+ if (clear_pending)
+ entry->next = NULL;
+ entry->prev = LIST_POISON2;
+}
+
+/*
+ * We are using hashed locking: holding per_cpu(tvec_bases).t_base.lock
+ * means that all timers which are tied to this base via timer->base are
+ * locked, and the base itself is locked too.
+ *
+ * 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.
+ */
+static timer_base_t *lock_timer_base(struct timer_list *timer,
+ unsigned long *flags)
+{
+ timer_base_t *base;
+
+ for (;;) {
+ base = timer->base;
+ if (likely(base != NULL)) {
+ spin_lock_irqsave(&base->lock, *flags);
+ if (likely(base == timer->base))
+ return base;
+ /* The timer has migrated to another CPU */
+ spin_unlock_irqrestore(&base->lock, *flags);
+ }
+ cpu_relax();
+ }
+}
+
int __mod_timer(struct timer_list *timer, unsigned long expires)
{
- tvec_base_t *old_base, *new_base;
+ timer_base_t *base;
+ tvec_base_t *new_base;
unsigned long flags;
int ret = 0;
BUG_ON(!timer->function);
- check_timer(timer);
+ base = lock_timer_base(timer, &flags);
+
+ if (timer_pending(timer)) {
+ detach_timer(timer, 0);
+ ret = 1;
+ }
- spin_lock_irqsave(&timer->lock, flags);
new_base = &__get_cpu_var(tvec_bases);
-repeat:
- old_base = timer->base;
- /*
- * Prevent deadlocks via ordering by old_base < new_base.
- */
- if (old_base && (new_base != old_base)) {
- if (old_base < new_base) {
- spin_lock(&new_base->lock);
- spin_lock(&old_base->lock);
- } else {
- spin_lock(&old_base->lock);
- spin_lock(&new_base->lock);
- }
+ if (base != &new_base->t_base) {
/*
- * The timer base might have been cancelled while we were
- * trying to take the lock(s):
+ * We are trying to schedule the timer on the local CPU.
+ * However we can't change timer's base while it is running,
+ * otherwise del_timer_sync() can't detect that the timer's
+ * handler yet has not finished. This also guarantees that
+ * the timer is serialized wrt itself.
*/
- if (timer->base != old_base) {
- spin_unlock(&new_base->lock);
- spin_unlock(&old_base->lock);
- goto repeat;
- }
- } else {
- spin_lock(&new_base->lock);
- if (timer->base != old_base) {
- spin_unlock(&new_base->lock);
- goto repeat;
+ if (unlikely(base->running_timer == timer)) {
+ /* The timer remains on a former base */
+ new_base = container_of(base, tvec_base_t, t_base);
+ } else {
+ /* 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;
}
}
- /*
- * Delete the previous timeout (if there was any), and install
- * the new one:
- */
- if (old_base) {
- list_del(&timer->entry);
- ret = 1;
- }
timer->expires = expires;
internal_add_timer(new_base, timer);
- timer->base = new_base;
-
- if (old_base && (new_base != old_base))
- spin_unlock(&old_base->lock);
- spin_unlock(&new_base->lock);
- spin_unlock_irqrestore(&timer->lock, flags);
+ spin_unlock_irqrestore(&new_base->t_base.lock, flags);
return ret;
}
{
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->lock, flags);
+ BUG_ON(timer_pending(timer) || !timer->function);
+ spin_lock_irqsave(&base->t_base.lock, flags);
+ timer->base = &base->t_base;
internal_add_timer(base, timer);
- timer->base = base;
- spin_unlock_irqrestore(&base->lock, flags);
+ spin_unlock_irqrestore(&base->t_base.lock, flags);
}
{
BUG_ON(!timer->function);
- check_timer(timer);
-
/*
* This is a common optimization triggered by the
* networking code - if the timer is re-modified
*/
int del_timer(struct timer_list *timer)
{
+ timer_base_t *base;
unsigned long flags;
- tvec_base_t *base;
-
- check_timer(timer);
+ int ret = 0;
-repeat:
- base = timer->base;
- if (!base)
- return 0;
- spin_lock_irqsave(&base->lock, flags);
- if (base != timer->base) {
+ if (timer_pending(timer)) {
+ base = lock_timer_base(timer, &flags);
+ if (timer_pending(timer)) {
+ detach_timer(timer, 1);
+ ret = 1;
+ }
spin_unlock_irqrestore(&base->lock, flags);
- goto repeat;
}
- list_del(&timer->entry);
- /* Need to make sure that anybody who sees a NULL base also sees the list ops */
- smp_wmb();
- timer->base = NULL;
- spin_unlock_irqrestore(&base->lock, flags);
- return 1;
+ return ret;
}
EXPORT_SYMBOL(del_timer);
#ifdef CONFIG_SMP
-/***
- * del_timer_sync - deactivate a timer and wait for the handler to finish.
- * @timer: the timer to be deactivated
- *
- * This function only differs from del_timer() on SMP: besides deactivating
- * the timer it also makes sure the handler has finished executing on other
- * CPUs.
- *
- * 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. Upon exit the timer is not queued and
- * the handler is not running on any CPU.
- *
- * The function returns whether it has deactivated a pending timer or not.
+/*
+ * 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.
*
- * del_timer_sync() is slow and complicated because it copes with timer
- * handlers which re-arm the timer (periodic timers). If the timer handler
- * is known to not do this (a single shot timer) then use
- * del_singleshot_timer_sync() instead.
+ * It must not be called from interrupt contexts.
*/
-int del_timer_sync(struct timer_list *timer)
+int try_to_del_timer_sync(struct timer_list *timer)
{
- tvec_base_t *base;
- int i, ret = 0;
+ timer_base_t *base;
+ unsigned long flags;
+ int ret = -1;
- check_timer(timer);
+ base = lock_timer_base(timer, &flags);
-del_again:
- ret += del_timer(timer);
+ if (base->running_timer == timer)
+ goto out;
- for_each_online_cpu(i) {
- base = &per_cpu(tvec_bases, i);
- if (base->running_timer == timer) {
- while (base->running_timer == timer) {
- cpu_relax();
- preempt_check_resched();
- }
- break;
- }
+ ret = 0;
+ if (timer_pending(timer)) {
+ detach_timer(timer, 1);
+ ret = 1;
}
- smp_rmb();
- if (timer_pending(timer))
- goto del_again;
+out:
+ spin_unlock_irqrestore(&base->lock, flags);
return ret;
}
-EXPORT_SYMBOL(del_timer_sync);
/***
- * del_singleshot_timer_sync - deactivate a non-recursive timer
+ * del_timer_sync - deactivate a timer and wait for the handler to finish.
* @timer: the timer to be deactivated
*
- * This function is an optimization of del_timer_sync for the case where the
- * caller can guarantee the timer does not reschedule itself in its timer
- * function.
+ * This function only differs from del_timer() on SMP: besides deactivating
+ * the timer it also makes sure the handler has finished executing on other
+ * CPUs.
*
* 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 wold prevent
- * completion of the timer's handler. Upon exit the timer is not queued and
- * the handler is not running on any CPU.
+ * interrupt contexts. The caller must not hold locks which would prevent
+ * completion of the timer's handler. The timer's handler must not call
+ * add_timer_on(). Upon exit the timer is not queued and the handler is
+ * not running on any CPU.
*
* The function returns whether it has deactivated a pending timer or not.
*/
-int del_singleshot_timer_sync(struct timer_list *timer)
+int del_timer_sync(struct timer_list *timer)
{
- int ret = del_timer(timer);
-
- if (!ret) {
- ret = del_timer_sync(timer);
- BUG_ON(ret);
+ for (;;) {
+ int ret = try_to_del_timer_sync(timer);
+ if (ret >= 0)
+ return ret;
}
-
- return ret;
}
-EXPORT_SYMBOL(del_singleshot_timer_sync);
+
+EXPORT_SYMBOL(del_timer_sync);
#endif
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);
+ BUG_ON(tmp->base != &base->t_base);
curr = curr->next;
internal_add_timer(base, tmp);
}
{
struct timer_list *timer;
- spin_lock_irq(&base->lock);
+ spin_lock_irq(&base->t_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;
cascade(base, &base->tv5, INDEX(3));
++base->timer_jiffies;
list_splice_init(base->tv1.vec + index, &work_list);
-repeat:
- if (!list_empty(head)) {
+ while (!list_empty(head)) {
void (*fn)(unsigned long);
unsigned long data;
fn = timer->function;
data = timer->data;
- list_del(&timer->entry);
set_running_timer(base, timer);
- smp_wmb();
- timer->base = NULL;
- spin_unlock_irq(&base->lock);
+ detach_timer(timer, 1);
+ spin_unlock_irq(&base->t_base.lock);
{
- u32 preempt_count = preempt_count();
+ int preempt_count = preempt_count();
fn(data);
if (preempt_count != preempt_count()) {
- printk("huh, entered %p with %08x, exited with %08x?\n", fn, preempt_count, preempt_count());
+ printk(KERN_WARNING "huh, entered %p "
+ "with preempt_count %08x, exited"
+ " with %08x?\n",
+ fn, preempt_count,
+ preempt_count());
BUG();
}
}
- spin_lock_irq(&base->lock);
- goto repeat;
+ spin_lock_irq(&base->t_base.lock);
}
}
set_running_timer(base, NULL);
- spin_unlock_irq(&base->lock);
+ spin_unlock_irq(&base->t_base.lock);
}
#ifdef CONFIG_NO_IDLE_HZ
struct list_head *list;
struct timer_list *nte;
unsigned long expires;
+ unsigned long hr_expires = MAX_JIFFY_OFFSET;
+ ktime_t hr_delta;
tvec_t *varray[4];
int i, j;
+ hr_delta = hrtimer_get_next_event();
+ if (hr_delta.tv64 != KTIME_MAX) {
+ struct timespec tsdelta;
+ tsdelta = ktime_to_timespec(hr_delta);
+ hr_expires = timespec_to_jiffies(&tsdelta);
+ if (hr_expires < 3)
+ return hr_expires + jiffies;
+ }
+ hr_expires += jiffies;
+
base = &__get_cpu_var(tvec_bases);
- spin_lock(&base->lock);
+ spin_lock(&base->t_base.lock);
expires = base->timer_jiffies + (LONG_MAX >> 1);
- list = 0;
+ list = NULL;
/* Look for timer events in tv1. */
j = base->timer_jiffies & TVR_MASK;
expires = nte->expires;
}
}
- spin_unlock(&base->lock);
+ spin_unlock(&base->t_base.lock);
+
+ if (time_before(hr_expires, expires))
+ return hr_expires;
+
return expires;
}
#endif
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) */
-long time_phase; /* phase offset (scaled 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)*/
-long time_adj; /* tick adjust (scaled 1 / HZ) */
+static long time_adj; /* tick adjust (scaled 1 / HZ) */
long time_reftime; /* time at last adjustment (s) */
long time_adjust;
long time_next_adjust;
*/
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");
+ 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;
}
- 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");
+
+ /*
+ * 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;
}
- 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 {
+
+ /*
+ * 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.
+ */
ltemp = time_offset;
if (!(time_status & STA_FLL))
- ltemp >>= SHIFT_KG + time_constant;
- if (ltemp > (MAXPHASE / MINSEC) << SHIFT_UPDATE)
- ltemp = (MAXPHASE / MINSEC) << SHIFT_UPDATE;
+ ltemp = shift_right(ltemp, SHIFT_KG + time_constant);
+ ltemp = min(ltemp, (MAXPHASE / MINSEC) << SHIFT_UPDATE);
+ ltemp = max(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);
+
+ /*
+ * 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;
+ time_adj += shift_right(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);
+ /*
+ * Compensate for (HZ==100) != (1 << SHIFT_HZ). Add 25% and 3.125% to
+ * get 128.125; => only 0.125% error (p. 14)
+ */
+ time_adj += shift_right(time_adj, 2) + shift_right(time_adj, 5);
+#endif
+#if HZ == 250
+ /*
+ * Compensate for (HZ==250) != (1 << SHIFT_HZ). Add 1.5625% and
+ * 0.78125% to get 255.85938; => only 0.05% error (p. 14)
+ */
+ time_adj += shift_right(time_adj, 6) + shift_right(time_adj, 7);
#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);
+ /*
+ * Compensate for (HZ==1000) != (1 << SHIFT_HZ). Add 1.5625% and
+ * 0.78125% to get 1023.4375; => only 0.05% error (p. 14)
+ */
+ time_adj += shift_right(time_adj, 6) + shift_right(time_adj, 7);
#endif
}
+/*
+ * Returns how many microseconds we need to add to xtime this tick
+ * in doing an adjustment requested with adjtime.
+ */
+static long adjtime_adjustment(void)
+{
+ long time_adjust_step;
+
+ time_adjust_step = time_adjust;
+ if (time_adjust_step) {
+ /*
+ * 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
+ */
+ time_adjust_step = min(time_adjust_step, (long)tickadj);
+ time_adjust_step = max(time_adjust_step, (long)-tickadj);
+ }
+ return time_adjust_step;
+}
+
/* 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;
- }
+ time_adjust_step = adjtime_adjustment();
+ if (time_adjust_step)
+ /* 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.
*/
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);
+ if ((time_phase >= FINENSEC) || (time_phase <= -FINENSEC)) {
+ long ltemp = shift_right(time_phase, (SHIFT_SCALE - 10));
time_phase -= ltemp << (SHIFT_SCALE - 10);
delta_nsec += ltemp;
}
}
}
+/*
+ * Return how long ticks are at the moment, that is, how much time
+ * update_wall_time_one_tick will add to xtime next time we call it
+ * (assuming no calls to do_adjtimex in the meantime).
+ * The return value is in fixed-point nanoseconds with SHIFT_SCALE-10
+ * bits to the right of the binary point.
+ * This function has no side-effects.
+ */
+u64 current_tick_length(void)
+{
+ long delta_nsec;
+
+ delta_nsec = tick_nsec + adjtime_adjustment() * 1000;
+ return ((u64) delta_nsec << (SHIFT_SCALE - 10)) + time_adj;
+}
+
/*
* Using a loop looks inefficient, but "ticks" is
* usually just one (we shouldn't be losing ticks,
if (rcu_pending(cpu))
rcu_check_callbacks(cpu, user_tick);
scheduler_tick();
+ run_posix_cpu_timers(p);
}
/*
*/
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.
{
tvec_base_t *base = &__get_cpu_var(tvec_bases);
+ hrtimer_run_queues();
if (time_after_eq(jiffies, base->timer_jiffies))
__run_timers(base);
}
void do_timer(struct pt_regs *regs)
{
jiffies_64++;
+ /* prevent loading jiffies before storing new jiffies_64 value. */
+ barrier();
update_times();
+ softlockup_tick(regs);
}
#ifdef __ARCH_WANT_SYS_ALARM
#endif
-#ifndef __alpha__
-
-/*
- * The Alpha uses getxpid, getxuid, and getxgid instead. Maybe this
- * should be moved into arch/i386 instead?
- */
/**
* sys_getpid - return the thread group id of the current process
}
/*
- * 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)
{
int pid;
- struct task_struct *me = current;
- struct task_struct *parent;
- parent = me->group_leader->real_parent;
- for (;;) {
- pid = parent->tgid;
-#ifdef CONFIG_SMP
-{
- struct task_struct *old = parent;
+ rcu_read_lock();
+ pid = rcu_dereference(current->real_parent)->tgid;
+ rcu_read_unlock();
- /*
- * Make sure we read the pid before re-reading the
- * parent pointer:
- */
- rmb();
- parent = me->group_leader->real_parent;
- if (old != parent)
- continue;
-}
-#endif
- break;
- }
return vx_map_pid(pid);
}
+#ifdef __alpha__
+
+/*
+ * The Alpha uses getxpid, getxuid, and getxgid instead.
+ */
+
+asmlinkage long do_getxpid(long *ppid)
+{
+ *ppid = sys_getppid();
+ return sys_getpid();
+}
+
+#else /* _alpha_ */
+
asmlinkage long sys_getuid(void)
{
/* Only we change this so SMP safe */
if (timeout < 0)
{
printk(KERN_ERR "schedule_timeout: wrong timeout "
- "value %lx from %p\n", timeout,
- __builtin_return_address(0));
+ "value %lx from %p\n", timeout,
+ __builtin_return_address(0));
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(&timer, process_timeout, (unsigned long)current);
+ __mod_timer(&timer, expire);
schedule();
del_singleshot_timer_sync(&timer);
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_uninterruptible(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_UNINTERRUPTIBLE);
+ return schedule_timeout(timeout);
}
+EXPORT_SYMBOL(schedule_timeout_uninterruptible);
-asmlinkage long sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp)
+/* Thread ID - the internal kernel "pid" */
+asmlinkage long sys_gettid(void)
{
- 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);
-
- 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;
+ return current->pid;
}
/*
val.procs = nr_threads;
} while (read_seqretry(&xtime_lock, seq));
-/* if (vx_flags(VXF_VIRT_CPU, 0))
- vx_vsi_cpu(val);
-*/
si_meminfo(&val);
si_swapinfo(&val);
{
int j;
tvec_base_t *base;
-
+
base = &per_cpu(tvec_bases, cpu);
- spin_lock_init(&base->lock);
+ 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);
}
#ifdef CONFIG_HOTPLUG_CPU
-static int migrate_timer_list(tvec_base_t *new_base, struct list_head *head)
+static void migrate_timer_list(tvec_base_t *new_base, struct list_head *head)
{
struct timer_list *timer;
while (!list_empty(head)) {
timer = list_entry(head->next, struct timer_list, entry);
- /* We're locking backwards from __mod_timer order here,
- beware deadlock. */
- if (!spin_trylock(&timer->lock))
- return 0;
- list_del(&timer->entry);
+ detach_timer(timer, 0);
+ timer->base = &new_base->t_base;
internal_add_timer(new_base, timer);
- timer->base = new_base;
- spin_unlock(&timer->lock);
}
- return 1;
}
static void __devinit migrate_timers(int cpu)
new_base = &get_cpu_var(tvec_bases);
local_irq_disable();
-again:
- /* Prevent deadlocks via ordering by old_base < new_base. */
- if (old_base < new_base) {
- spin_lock(&new_base->lock);
- spin_lock(&old_base->lock);
- } else {
- spin_lock(&old_base->lock);
- spin_lock(&new_base->lock);
- }
+ spin_lock(&new_base->t_base.lock);
+ spin_lock(&old_base->t_base.lock);
- if (old_base->running_timer)
+ if (old_base->t_base.running_timer)
BUG();
for (i = 0; i < TVR_SIZE; i++)
- if (!migrate_timer_list(new_base, old_base->tv1.vec + i))
- goto unlock_again;
- for (i = 0; i < TVN_SIZE; i++)
- if (!migrate_timer_list(new_base, old_base->tv2.vec + i)
- || !migrate_timer_list(new_base, old_base->tv3.vec + i)
- || !migrate_timer_list(new_base, old_base->tv4.vec + i)
- || !migrate_timer_list(new_base, old_base->tv5.vec + i))
- goto unlock_again;
- spin_unlock(&old_base->lock);
- spin_unlock(&new_base->lock);
+ migrate_timer_list(new_base, old_base->tv1.vec + i);
+ for (i = 0; i < TVN_SIZE; i++) {
+ migrate_timer_list(new_base, old_base->tv2.vec + i);
+ migrate_timer_list(new_base, old_base->tv3.vec + i);
+ migrate_timer_list(new_base, old_base->tv4.vec + 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();
put_cpu_var(tvec_bases);
- return;
-
-unlock_again:
- /* Avoid deadlock with __mod_timer, by backing off. */
- spin_unlock(&old_base->lock);
- spin_unlock(&new_base->lock);
- cpu_relax();
- goto again;
}
#endif /* CONFIG_HOTPLUG_CPU */
#ifdef CONFIG_TIME_INTERPOLATION
-struct time_interpolator *time_interpolator;
-static struct time_interpolator *time_interpolator_list;
+struct time_interpolator *time_interpolator __read_mostly;
+static struct time_interpolator *time_interpolator_list __read_mostly;
static DEFINE_SPINLOCK(time_interpolator_lock);
static inline u64 time_interpolator_get_cycles(unsigned int src)
return x();
case TIME_SOURCE_MMIO64 :
- return readq((void __iomem *) time_interpolator->addr);
+ return readq_relaxed((void __iomem *)time_interpolator->addr);
case TIME_SOURCE_MMIO32 :
- return readl((void __iomem *) time_interpolator->addr);
+ return readl_relaxed((void __iomem *)time_interpolator->addr);
default: return get_cycles();
}
}
-static inline u64 time_interpolator_get_counter(void)
+static inline u64 time_interpolator_get_counter(int writelock)
{
unsigned int src = time_interpolator->source;
now = time_interpolator_get_cycles(src);
if (lcycle && time_after(lcycle, now))
return lcycle;
+
+ /* When holding the xtime write lock, there's no need
+ * to add the overhead of the cmpxchg. Readers are
+ * force to retry until the write lock is released.
+ */
+ if (writelock) {
+ time_interpolator->last_cycle = now;
+ return now;
+ }
/* Keep track of the last timer value returned. The use of cmpxchg here
* will cause contention in an SMP environment.
*/
void time_interpolator_reset(void)
{
time_interpolator->offset = 0;
- time_interpolator->last_counter = time_interpolator_get_counter();
+ time_interpolator->last_counter = time_interpolator_get_counter(1);
}
#define GET_TI_NSECS(count,i) (((((count) - i->last_counter) & (i)->mask) * (i)->nsec_per_cyc) >> (i)->shift)
return 0;
return time_interpolator->offset +
- GET_TI_NSECS(time_interpolator_get_counter(), time_interpolator);
+ GET_TI_NSECS(time_interpolator_get_counter(0), time_interpolator);
}
#define INTERPOLATOR_ADJUST 65536
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.
- */
+ /*
+ * 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);
+ counter = time_interpolator_get_counter(1);
+ 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;
{
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);
/**
- * msleep_interruptible - sleep waiting for waitqueue interruptions
+ * msleep_interruptible - sleep waiting for signals
* @msecs: Time in milliseconds to sleep for
*/
unsigned long msleep_interruptible(unsigned int msecs)
{
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://git.onelab.eu / linux-2.6.git / blobdiff