tvec_base_t boot_tvec_bases;
EXPORT_SYMBOL(boot_tvec_bases);
-static DEFINE_PER_CPU(tvec_base_t *, tvec_bases) = &boot_tvec_bases;
+static DEFINE_PER_CPU(tvec_base_t *, tvec_bases) = { &boot_tvec_bases };
static inline void set_running_timer(tvec_base_t *base,
struct timer_list *timer)
void fastcall init_timer(struct timer_list *timer)
{
timer->entry.next = NULL;
- timer->base = __raw_get_cpu_var(tvec_bases);
+ timer->base = per_cpu(tvec_bases, raw_smp_processor_id());
}
EXPORT_SYMBOL(init_timer);
int ret = try_to_del_timer_sync(timer);
if (ret >= 0)
return ret;
- cpu_relax();
}
}
static int cascade(tvec_base_t *base, tvec_t *tv, int index)
{
/* cascade all the timers from tv up one level */
- struct timer_list *timer, *tmp;
- struct list_head tv_list;
-
- list_replace_init(tv->vec + index, &tv_list);
+ struct list_head *head, *curr;
+ head = tv->vec + index;
+ curr = head->next;
/*
- * We are removing _all_ timers from the list, so we
- * don't have to detach them individually.
+ * We are removing _all_ timers from the list, so we don't have to
+ * detach them individually, just clear the list afterwards.
*/
- list_for_each_entry_safe(timer, tmp, &tv_list, entry) {
- BUG_ON(timer->base != base);
- internal_add_timer(base, timer);
+ while (curr != head) {
+ struct timer_list *tmp;
+
+ tmp = list_entry(curr, struct timer_list, entry);
+ BUG_ON(tmp->base != base);
+ curr = curr->next;
+ internal_add_timer(base, tmp);
}
+ INIT_LIST_HEAD(head);
return index;
}
* This function cascades all vectors and executes all expired timer
* vectors.
*/
-#define INDEX(N) ((base->timer_jiffies >> (TVR_BITS + (N) * TVN_BITS)) & TVN_MASK)
+#define INDEX(N) (base->timer_jiffies >> (TVR_BITS + N * TVN_BITS)) & TVN_MASK
static inline void __run_timers(tvec_base_t *base)
{
spin_lock_irq(&base->lock);
while (time_after_eq(jiffies, base->timer_jiffies)) {
- struct list_head work_list;
+ struct list_head work_list = LIST_HEAD_INIT(work_list);
struct list_head *head = &work_list;
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_replace_init(base->tv1.vec + index, &work_list);
+ ++base->timer_jiffies;
+ list_splice_init(base->tv1.vec + index, &work_list);
while (!list_empty(head)) {
void (*fn)(unsigned long);
unsigned long data;
}
spin_unlock(&base->lock);
+ /*
+ * It can happen that other CPUs service timer IRQs and increment
+ * jiffies, but we have not yet got a local timer tick to process
+ * the timer wheels. In that case, the expiry time can be before
+ * jiffies, but since the high-resolution timer here is relative to
+ * jiffies, the default expression when high-resolution timers are
+ * not active,
+ *
+ * time_before(MAX_JIFFY_OFFSET + jiffies, expires)
+ *
+ * would falsely evaluate to true. If that is the case, just
+ * return jiffies so that we can immediately fire the local timer
+ */
+ if (time_before(expires, jiffies))
+ return jiffies;
+
/*
* It can happen that other CPUs service timer IRQs and increment
* jiffies, but we have not yet got a local timer tick to process
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) */
}
/* in the NTP reference this is called "hardclock()" */
-static void update_ntp_one_tick(void)
+static void update_wall_time_one_tick(void)
{
- long time_adjust_step;
+ long time_adjust_step, delta_nsec;
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) || (time_phase <= -FINENSEC)) {
+ long ltemp = shift_right(time_phase, (SHIFT_SCALE - 10));
+ time_phase -= ltemp << (SHIFT_SCALE - 10);
+ delta_nsec += ltemp;
+ }
+ xtime.tv_nsec += delta_nsec;
+ time_interpolator_update(delta_nsec);
/* Changes by adjtime() do not take effect till next tick. */
if (time_next_adjust != 0) {
* 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 shifted by the
- * specified number of bits to the right of the binary point.
+ * 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;
- u64 ret;
- /* calculate the finest interval NTP will allow.
- * ie: nanosecond value shifted by (SHIFT_SCALE - 10)
- */
delta_nsec = tick_nsec + adjtime_adjustment() * 1000;
- ret = (u64)delta_nsec << TICK_LENGTH_SHIFT;
- ret += (s64)time_adj << (TICK_LENGTH_SHIFT - (SHIFT_SCALE - 10));
-
- return ret;
-}
-
-/* XXX - all of this timekeeping code should be later moved to time.c */
-#include <linux/clocksource.h>
-static struct clocksource *clock; /* pointer to current clocksource */
-
-#ifdef CONFIG_GENERIC_TIME
-/**
- * __get_nsec_offset - Returns nanoseconds since last call to periodic_hook
- *
- * private function, must hold xtime_lock lock when being
- * called. Returns the number of nanoseconds since the
- * last call to update_wall_time() (adjusted by NTP scaling)
- */
-static inline s64 __get_nsec_offset(void)
-{
- cycle_t cycle_now, cycle_delta;
- s64 ns_offset;
-
- /* read clocksource: */
- cycle_now = clocksource_read(clock);
-
- /* calculate the delta since the last update_wall_time: */
- cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
-
- /* convert to nanoseconds: */
- ns_offset = cyc2ns(clock, cycle_delta);
-
- return ns_offset;
-}
-
-/**
- * __get_realtime_clock_ts - Returns the time of day in a timespec
- * @ts: pointer to the timespec to be set
- *
- * Returns the time of day in a timespec. Used by
- * do_gettimeofday() and get_realtime_clock_ts().
- */
-static inline void __get_realtime_clock_ts(struct timespec *ts)
-{
- unsigned long seq;
- s64 nsecs;
-
- do {
- seq = read_seqbegin(&xtime_lock);
-
- *ts = xtime;
- nsecs = __get_nsec_offset();
-
- } while (read_seqretry(&xtime_lock, seq));
-
- timespec_add_ns(ts, nsecs);
-}
-
-/**
- * getnstimeofday - Returns the time of day in a timespec
- * @ts: pointer to the timespec to be set
- *
- * Returns the time of day in a timespec.
- */
-void getnstimeofday(struct timespec *ts)
-{
- __get_realtime_clock_ts(ts);
-}
-
-EXPORT_SYMBOL(getnstimeofday);
-
-/**
- * do_gettimeofday - Returns the time of day in a timeval
- * @tv: pointer to the timeval to be set
- *
- * NOTE: Users should be converted to using get_realtime_clock_ts()
- */
-void do_gettimeofday(struct timeval *tv)
-{
- struct timespec now;
-
- __get_realtime_clock_ts(&now);
- tv->tv_sec = now.tv_sec;
- tv->tv_usec = now.tv_nsec/1000;
-}
-
-EXPORT_SYMBOL(do_gettimeofday);
-/**
- * do_settimeofday - Sets the time of day
- * @tv: pointer to the timespec variable containing the new time
- *
- * Sets the time of day to the new time and update NTP and notify hrtimers
- */
-int do_settimeofday(struct timespec *tv)
-{
- unsigned long flags;
- time_t wtm_sec, sec = tv->tv_sec;
- long wtm_nsec, nsec = tv->tv_nsec;
-
- if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
- return -EINVAL;
-
- write_seqlock_irqsave(&xtime_lock, flags);
-
- nsec -= __get_nsec_offset();
-
- wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
- wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
-
- set_normalized_timespec(&xtime, sec, nsec);
- set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
-
- clock->error = 0;
- ntp_clear();
-
- write_sequnlock_irqrestore(&xtime_lock, flags);
-
- /* signal hrtimers about time change */
- clock_was_set();
-
- return 0;
-}
-
-EXPORT_SYMBOL(do_settimeofday);
-
-/**
- * change_clocksource - Swaps clocksources if a new one is available
- *
- * Accumulates current time interval and initializes new clocksource
- */
-static int change_clocksource(void)
-{
- struct clocksource *new;
- cycle_t now;
- u64 nsec;
- new = clocksource_get_next();
- if (clock != new) {
- now = clocksource_read(new);
- nsec = __get_nsec_offset();
- timespec_add_ns(&xtime, nsec);
-
- clock = new;
- clock->cycle_last = now;
- printk(KERN_INFO "Time: %s clocksource has been installed.\n",
- clock->name);
- return 1;
- } else if (clock->update_callback) {
- return clock->update_callback();
- }
- return 0;
-}
-#else
-#define change_clocksource() (0)
-#endif
-
-/**
- * timeofday_is_continuous - check to see if timekeeping is free running
- */
-int timekeeping_is_continuous(void)
-{
- unsigned long seq;
- int ret;
-
- do {
- seq = read_seqbegin(&xtime_lock);
-
- ret = clock->is_continuous;
-
- } while (read_seqretry(&xtime_lock, seq));
-
- return ret;
-}
-
-/*
- * timekeeping_init - Initializes the clocksource and common timekeeping values
- */
-void __init timekeeping_init(void)
-{
- unsigned long flags;
-
- write_seqlock_irqsave(&xtime_lock, flags);
- clock = clocksource_get_next();
- clocksource_calculate_interval(clock, tick_nsec);
- clock->cycle_last = clocksource_read(clock);
- ntp_clear();
- write_sequnlock_irqrestore(&xtime_lock, flags);
-}
-
-
-static int timekeeping_suspended;
-/*
- * timekeeping_resume - Resumes the generic timekeeping subsystem.
- * @dev: unused
- *
- * This is for the generic clocksource timekeeping.
- * xtime/wall_to_monotonic/jiffies/wall_jiffies/etc are
- * still managed by arch specific suspend/resume code.
- */
-static int timekeeping_resume(struct sys_device *dev)
-{
- unsigned long flags;
-
- write_seqlock_irqsave(&xtime_lock, flags);
- /* restart the last cycle value */
- clock->cycle_last = clocksource_read(clock);
- clock->error = 0;
- timekeeping_suspended = 0;
- write_sequnlock_irqrestore(&xtime_lock, flags);
- return 0;
-}
-
-static int timekeeping_suspend(struct sys_device *dev, pm_message_t state)
-{
- unsigned long flags;
-
- write_seqlock_irqsave(&xtime_lock, flags);
- timekeeping_suspended = 1;
- write_sequnlock_irqrestore(&xtime_lock, flags);
- return 0;
-}
-
-/* sysfs resume/suspend bits for timekeeping */
-static struct sysdev_class timekeeping_sysclass = {
- .resume = timekeeping_resume,
- .suspend = timekeeping_suspend,
- set_kset_name("timekeeping"),
-};
-
-static struct sys_device device_timer = {
- .id = 0,
- .cls = &timekeeping_sysclass,
-};
-
-static int __init timekeeping_init_device(void)
-{
- int error = sysdev_class_register(&timekeeping_sysclass);
- if (!error)
- error = sysdev_register(&device_timer);
- return error;
-}
-
-device_initcall(timekeeping_init_device);
-
-/*
- * If the error is already larger, we look ahead even further
- * to compensate for late or lost adjustments.
- */
-static __always_inline int clocksource_bigadjust(s64 error, s64 *interval, s64 *offset)
-{
- s64 tick_error, i;
- u32 look_ahead, adj;
- s32 error2, mult;
-
- /*
- * Use the current error value to determine how much to look ahead.
- * The larger the error the slower we adjust for it to avoid problems
- * with losing too many ticks, otherwise we would overadjust and
- * produce an even larger error. The smaller the adjustment the
- * faster we try to adjust for it, as lost ticks can do less harm
- * here. This is tuned so that an error of about 1 msec is adusted
- * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks).
- */
- error2 = clock->error >> (TICK_LENGTH_SHIFT + 22 - 2 * SHIFT_HZ);
- error2 = abs(error2);
- for (look_ahead = 0; error2 > 0; look_ahead++)
- error2 >>= 2;
-
- /*
- * Now calculate the error in (1 << look_ahead) ticks, but first
- * remove the single look ahead already included in the error.
- */
- tick_error = current_tick_length() >> (TICK_LENGTH_SHIFT - clock->shift + 1);
- tick_error -= clock->xtime_interval >> 1;
- error = ((error - tick_error) >> look_ahead) + tick_error;
-
- /* Finally calculate the adjustment shift value. */
- i = *interval;
- mult = 1;
- if (error < 0) {
- error = -error;
- *interval = -*interval;
- *offset = -*offset;
- mult = -1;
- }
- for (adj = 0; error > i; adj++)
- error >>= 1;
-
- *interval <<= adj;
- *offset <<= adj;
- return mult << adj;
+ return ((u64) delta_nsec << (SHIFT_SCALE - 10)) + time_adj;
}
/*
- * Adjust the multiplier to reduce the error value,
- * this is optimized for the most common adjustments of -1,0,1,
- * for other values we can do a bit more work.
+ * 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
*/
-static void clocksource_adjust(struct clocksource *clock, s64 offset)
+static void update_wall_time(unsigned long ticks)
{
- s64 error, interval = clock->cycle_interval;
- int adj;
-
- error = clock->error >> (TICK_LENGTH_SHIFT - clock->shift - 1);
- if (error > interval) {
- error >>= 2;
- if (likely(error <= interval))
- adj = 1;
- else
- adj = clocksource_bigadjust(error, &interval, &offset);
- } else if (error < -interval) {
- error >>= 2;
- if (likely(error >= -interval)) {
- adj = -1;
- interval = -interval;
- offset = -offset;
- } else
- adj = clocksource_bigadjust(error, &interval, &offset);
- } else
- return;
-
- clock->mult += adj;
- clock->xtime_interval += interval;
- clock->xtime_nsec -= offset;
- clock->error -= (interval - offset) << (TICK_LENGTH_SHIFT - clock->shift);
-}
-
-/*
- * update_wall_time - Uses the current clocksource to increment the wall time
- *
- * Called from the timer interrupt, must hold a write on xtime_lock.
- */
-static void update_wall_time(void)
-{
- cycle_t offset;
-
- /* Make sure we're fully resumed: */
- if (unlikely(timekeeping_suspended))
- return;
-
-#ifdef CONFIG_GENERIC_TIME
- offset = (clocksource_read(clock) - clock->cycle_last) & clock->mask;
-#else
- offset = clock->cycle_interval;
-#endif
- clock->xtime_nsec += (s64)xtime.tv_nsec << clock->shift;
-
- /* normally this loop will run just once, however in the
- * case of lost or late ticks, it will accumulate correctly.
- */
- while (offset >= clock->cycle_interval) {
- /* accumulate one interval */
- clock->xtime_nsec += clock->xtime_interval;
- clock->cycle_last += clock->cycle_interval;
- offset -= clock->cycle_interval;
-
- if (clock->xtime_nsec >= (u64)NSEC_PER_SEC << clock->shift) {
- clock->xtime_nsec -= (u64)NSEC_PER_SEC << clock->shift;
+ do {
+ ticks--;
+ update_wall_time_one_tick();
+ if (xtime.tv_nsec >= 1000000000) {
+ xtime.tv_nsec -= 1000000000;
xtime.tv_sec++;
second_overflow();
}
-
- /* interpolator bits */
- time_interpolator_update(clock->xtime_interval
- >> clock->shift);
- /* increment the NTP state machine */
- update_ntp_one_tick();
-
- /* accumulate error between NTP and clock interval */
- clock->error += current_tick_length();
- clock->error -= clock->xtime_interval << (TICK_LENGTH_SHIFT - clock->shift);
- }
-
- /* correct the clock when NTP error is too big */
- clocksource_adjust(clock, offset);
-
- /* store full nanoseconds into xtime */
- xtime.tv_nsec = (s64)clock->xtime_nsec >> clock->shift;
- clock->xtime_nsec -= (s64)xtime.tv_nsec << clock->shift;
-
- /* check to see if there is a new clocksource to use */
- if (change_clocksource()) {
- clock->error = 0;
- clock->xtime_nsec = 0;
- clocksource_calculate_interval(clock, tick_nsec);
- }
+ } while (ticks);
}
/*
* playing with xtime and avenrun.
*/
#ifndef ARCH_HAVE_XTIME_LOCK
-__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
+seqlock_t xtime_lock __cacheline_aligned_in_smp = SEQLOCK_UNLOCKED;
EXPORT_SYMBOL(xtime_lock);
#endif
unsigned long ticks;
ticks = jiffies - wall_jiffies;
- wall_jiffies += ticks;
- update_wall_time();
+ if (ticks) {
+ wall_jiffies += ticks;
+ update_wall_time(ticks);
+ }
calc_load(ticks);
}
static void process_timeout(unsigned long __data)
{
- wake_up_process((struct task_struct *)__data);
+ wake_up_process((task_t *)__data);
}
/**
return 0;
}
-/*
- * lockdep: we want to track each per-CPU base as a separate lock-class,
- * but timer-bases are kmalloc()-ed, so we need to attach separate
- * keys to them:
- */
-static struct lock_class_key base_lock_keys[NR_CPUS];
-
static int __devinit init_timers_cpu(int cpu)
{
int j;
}
spin_lock_init(&base->lock);
- lockdep_set_class(&base->lock, base_lock_keys + cpu);
-
for (j = 0; j < TVN_SIZE; j++) {
INIT_LIST_HEAD(base->tv5.vec + j);
INIT_LIST_HEAD(base->tv4.vec + j);
}
#endif /* CONFIG_HOTPLUG_CPU */
-static int __cpuinit timer_cpu_notify(struct notifier_block *self,
+static int timer_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
long cpu = (long)hcpu;
return NOTIFY_OK;
}
-static struct notifier_block __cpuinitdata timers_nb = {
+static struct notifier_block timers_nb = {
.notifier_call = timer_cpu_notify,
};