#include <linux/cpu.h>
#include <linux/syscalls.h>
#include <linux/delay.h>
+#include <linux/vs_base.h>
#include <linux/vs_cvirt.h>
+#include <linux/vs_pid.h>
#include <linux/vserver/sched.h>
#include <asm/uaccess.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
-
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 list_head vec[TVN_SIZE];
} tvec_t;
} tvec_root_t;
struct tvec_t_base_s {
- struct timer_base_s t_base;
+ spinlock_t lock;
+ struct timer_list *running_timer;
unsigned long timer_jiffies;
tvec_root_t tv1;
tvec_t tv2;
} ____cacheline_aligned_in_smp;
typedef struct tvec_t_base_s tvec_base_t;
-static DEFINE_PER_CPU(tvec_base_t, tvec_bases);
+
+tvec_base_t boot_tvec_bases;
+EXPORT_SYMBOL(boot_tvec_bases);
+static DEFINE_PER_CPU(tvec_base_t *, tvec_bases) = &boot_tvec_bases;
+
+/**
+ * __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)
+{
+ int rem;
+ unsigned long original = j;
+
+ /*
+ * 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.
+ */
+ 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.
+ */
+ if (rem < HZ/4) /* 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;
+}
+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)
+{
+ /*
+ * In theory the following code can skip a jiffy in case jiffies
+ * increments right between the addition and the later subtraction.
+ * However since the entire point of this function is to use approximate
+ * timeouts, it's entirely ok to not handle that.
+ */
+ return __round_jiffies(j + jiffies, cpu) - jiffies;
+}
+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(j, raw_smp_processor_id());
+}
+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);
+
static inline void set_running_timer(tvec_base_t *base,
struct timer_list *timer)
{
#ifdef CONFIG_SMP
- base->t_base.running_timer = timer;
+ base->running_timer = timer;
#endif
}
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
*
void fastcall init_timer(struct timer_list *timer)
{
timer->entry.next = NULL;
- timer->base = &per_cpu(tvec_bases, raw_smp_processor_id()).t_base;
+ timer->base = __raw_get_cpu_var(tvec_bases);
}
EXPORT_SYMBOL(init_timer);
}
/*
- * We are using hashed locking: holding per_cpu(tvec_bases).t_base.lock
+ * We are using hashed locking: holding per_cpu(tvec_bases).lock
* means that all timers which are tied to this base via timer->base are
* locked, and the base itself is locked too.
*
* possible to set timer->base = NULL and drop the lock: the timer remains
* locked.
*/
-static timer_base_t *lock_timer_base(struct timer_list *timer,
+static tvec_base_t *lock_timer_base(struct timer_list *timer,
unsigned long *flags)
+ __acquires(timer->base->lock)
{
- timer_base_t *base;
+ tvec_base_t *base;
for (;;) {
base = timer->base;
int __mod_timer(struct timer_list *timer, unsigned long expires)
{
- timer_base_t *base;
- tvec_base_t *new_base;
+ tvec_base_t *base, *new_base;
unsigned long flags;
int ret = 0;
ret = 1;
}
- new_base = &__get_cpu_var(tvec_bases);
+ new_base = __get_cpu_var(tvec_bases);
- if (base != &new_base->t_base) {
+ if (base != new_base) {
/*
* We are trying to schedule the timer on the local CPU.
* However we can't change timer's base while it is running,
* handler yet has not finished. This also guarantees that
* the timer is serialized wrt itself.
*/
- if (unlikely(base->running_timer == timer)) {
- /* The timer remains on a former base */
- new_base = container_of(base, tvec_base_t, t_base);
- } else {
+ if (likely(base->running_timer != timer)) {
/* See the comment in lock_timer_base() */
timer->base = NULL;
spin_unlock(&base->lock);
- spin_lock(&new_base->t_base.lock);
- timer->base = &new_base->t_base;
+ base = new_base;
+ spin_lock(&base->lock);
+ timer->base = base;
}
}
timer->expires = expires;
- internal_add_timer(new_base, timer);
- spin_unlock_irqrestore(&new_base->t_base.lock, flags);
+ internal_add_timer(base, timer);
+ spin_unlock_irqrestore(&base->lock, flags);
return ret;
}
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
*/
void add_timer_on(struct timer_list *timer, int cpu)
{
- tvec_base_t *base = &per_cpu(tvec_bases, cpu);
+ tvec_base_t *base = per_cpu(tvec_bases, cpu);
unsigned long flags;
BUG_ON(timer_pending(timer) || !timer->function);
- spin_lock_irqsave(&base->t_base.lock, flags);
- timer->base = &base->t_base;
+ spin_lock_irqsave(&base->lock, flags);
+ timer->base = base;
internal_add_timer(base, timer);
- spin_unlock_irqrestore(&base->t_base.lock, flags);
+ spin_unlock_irqrestore(&base->lock, flags);
}
-/***
+/**
* 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
* active timer (if the timer is inactive it will be activated)
EXPORT_SYMBOL(mod_timer);
-/***
+/**
* del_timer - deactive a timer.
* @timer: the timer to be deactivated
*
*/
int del_timer(struct timer_list *timer)
{
- timer_base_t *base;
+ tvec_base_t *base;
unsigned long flags;
int ret = 0;
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;
+ tvec_base_t *base;
unsigned long flags;
int ret = -1;
return ret;
}
-/***
+/**
* del_timer_sync - deactivate a timer and wait for the handler to finish.
* @timer: the timer to be deactivated
*
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 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(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)
{
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;
-
+
/*
* 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;
set_running_timer(base, timer);
detach_timer(timer, 1);
- spin_unlock_irq(&base->t_base.lock);
+ spin_unlock_irq(&base->lock);
{
int preempt_count = preempt_count();
fn(data);
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
}
hr_expires += jiffies;
- base = &__get_cpu_var(tvec_bases);
- spin_lock(&base->t_base.lock);
+ base = __get_cpu_var(tvec_bases);
+ spin_lock(&base->lock);
expires = base->timer_jiffies + (LONG_MAX >> 1);
list = NULL;
expires = nte->expires;
}
}
- spin_unlock(&base->t_base.lock);
+ 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;
if (time_before(hr_expires, expires))
return hr_expires;
/******************************************************************/
-/*
- * Timekeeping variables
- */
-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
EXPORT_SYMBOL(xtime);
-/* Don't completely fail for HZ > 500. */
-int tickadj = 500/HZ ? : 1; /* microsecs */
+/* 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 */
-/*
- * phase-lock loop variables
+#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)
*/
-/* 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;
+static inline s64 __get_nsec_offset(void)
+{
+ cycle_t cycle_now, cycle_delta;
+ s64 ns_offset;
-/*
- * this routine handles the overflow of the microsecond field
+ /* 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
*
- * 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.
+ * 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.
*/
-static void second_overflow(void)
+void getnstimeofday(struct timespec *ts)
{
- long ltemp;
+ __get_realtime_clock_ts(ts);
+}
- /* 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;
- }
+EXPORT_SYMBOL(getnstimeofday);
- /*
- * 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;
- }
+/**
+ * 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;
- /*
- * 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_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);
+ __get_realtime_clock_ts(&now);
+ tv->tv_sec = now.tv_sec;
+ tv->tv_usec = now.tv_nsec/1000;
+}
- /*
- * 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));
+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 HZ == 100
- /*
- * 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)
- */
- time_adj += shift_right(time_adj, 6) + shift_right(time_adj, 7);
+ 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
+static inline int change_clocksource(void)
+{
+ return 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;
}
/*
- * Returns how many microseconds we need to add to xtime this tick
- * in doing an adjustment requested with adjtime.
+ * timekeeping_init - Initializes the clocksource and common timekeeping values
*/
-static long adjtime_adjustment(void)
+void __init timekeeping_init(void)
{
- long time_adjust_step;
+ unsigned long flags;
- 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;
+ write_seqlock_irqsave(&xtime_lock, flags);
+
+ ntp_clear();
+
+ clock = clocksource_get_next();
+ clocksource_calculate_interval(clock, tick_nsec);
+ clock->cycle_last = clocksource_read(clock);
+
+ 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/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;
}
-/* in the NTP reference this is called "hardclock()" */
-static void update_wall_time_one_tick(void)
+/* 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)
{
- long time_adjust_step, delta_nsec;
+ 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;
- 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.
+ * 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).
*/
- 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);
+ error2 = clock->error >> (TICK_LENGTH_SHIFT + 22 - 2 * SHIFT_HZ);
+ error2 = abs(error2);
+ for (look_ahead = 0; error2 > 0; look_ahead++)
+ error2 >>= 2;
- /* Changes by adjtime() do not take effect till next tick. */
- if (time_next_adjust != 0) {
- time_adjust = time_next_adjust;
- time_next_adjust = 0;
+ /*
+ * 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 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.
+ * 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.
*/
-u64 current_tick_length(void)
+static void clocksource_adjust(struct clocksource *clock, s64 offset)
{
- long delta_nsec;
+ 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;
- delta_nsec = tick_nsec + adjtime_adjustment() * 1000;
- return ((u64) delta_nsec << (SHIFT_SCALE - 10)) + time_adj;
+ clock->mult += adj;
+ clock->xtime_interval += interval;
+ clock->xtime_nsec -= offset;
+ clock->error -= (interval - offset) <<
+ (TICK_LENGTH_SHIFT - clock->shift);
}
-/*
- * 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
+/**
+ * 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(unsigned long ticks)
+static void update_wall_time(void)
{
- do {
- ticks--;
- update_wall_time_one_tick();
- if (xtime.tv_nsec >= 1000000000) {
- xtime.tv_nsec -= 1000000000;
+ 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;
xtime.tv_sec++;
second_overflow();
}
- } while (ticks);
+
+ /* interpolator bits */
+ time_interpolator_update(clock->xtime_interval
+ >> clock->shift);
+
+ /* 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);
+ }
}
/*
*/
static unsigned long count_active_tasks(void)
{
- return (nr_running() + nr_uninterruptible()) * FIXED_1;
+ return nr_active() * FIXED_1;
}
/*
static int count = LOAD_FREQ;
count -= ticks;
- if (count < 0) {
- count += LOAD_FREQ;
+ if (unlikely(count < 0)) {
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);
+ do {
+ CALC_LOAD(avenrun[0], EXP_1, active_tasks);
+ CALC_LOAD(avenrun[1], EXP_5, active_tasks);
+ CALC_LOAD(avenrun[2], EXP_15, active_tasks);
+ count += LOAD_FREQ;
+ } while (count < 0);
}
}
-/* 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;
+__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
EXPORT_SYMBOL(xtime_lock);
#endif
*/
static void run_timer_softirq(struct softirq_action *h)
{
- tvec_base_t *base = &__get_cpu_var(tvec_bases);
+ tvec_base_t *base = __get_cpu_var(tvec_bases);
hrtimer_run_queues();
if (time_after_eq(jiffies, base->timer_jiffies))
void run_local_timers(void)
{
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)
+static inline void update_times(unsigned long ticks)
{
- unsigned long ticks;
-
- ticks = jiffies - wall_jiffies;
- if (ticks) {
- wall_jiffies += ticks;
- update_wall_time(ticks);
- }
+ update_wall_time();
calc_load(ticks);
}
* jiffies is defined in the linker script...
*/
-void do_timer(struct pt_regs *regs)
+void do_timer(unsigned long ticks)
{
- jiffies_64++;
- /* prevent loading jiffies before storing new jiffies_64 value. */
- barrier();
- update_times();
- softlockup_tick(regs);
+ jiffies_64 += ticks;
+ update_times(ticks);
}
#ifdef __ARCH_WANT_SYS_ALARM
*/
asmlinkage unsigned long sys_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
}
/*
- * Accessing ->real_parent is not SMP-safe, it could
+ * Accessing ->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
+ * value of ->parent under rcu_read_lock(), see
* release_task()->call_rcu(delayed_put_task_struct).
*/
asmlinkage long sys_getppid(void)
int pid;
rcu_read_lock();
- pid = rcu_dereference(current->real_parent)->tgid;
+ pid = rcu_dereference(current->parent)->tgid;
rcu_read_unlock();
-
return vx_map_pid(pid);
}
static void process_timeout(unsigned long __data)
{
- wake_up_process((task_t *)__data);
+ wake_up_process((struct task_struct *)__data);
}
/**
* 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;
}
return current->pid;
}
-/*
+/**
* sys_sysinfo - fill in sysinfo struct
+ * @info: pointer to buffer to fill
*/
asmlinkage long sys_sysinfo(struct sysinfo __user *info)
{
return 0;
}
-static void __devinit init_timers_cpu(int cpu)
+/*
+ * 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;
tvec_base_t *base;
+ static char __devinitdata 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,
+ cpu_to_node(cpu));
+ if (!base)
+ return -ENOMEM;
+ memset(base, 0, sizeof(*base));
+ 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);
+ lockdep_set_class(&base->lock, base_lock_keys + cpu);
- 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;
+ return 0;
}
#ifdef CONFIG_HOTPLUG_CPU
while (!list_empty(head)) {
timer = list_entry(head->next, struct timer_list, entry);
detach_timer(timer, 0);
- timer->base = &new_base->t_base;
+ timer->base = new_base;
internal_add_timer(new_base, timer);
}
}
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);
local_irq_disable();
- spin_lock(&new_base->t_base.lock);
- spin_lock(&old_base->t_base.lock);
+ spin_lock(&new_base->lock);
+ spin_lock(&old_base->lock);
+
+ BUG_ON(old_base->running_timer);
- if (old_base->t_base.running_timer)
- BUG();
for (i = 0; i < TVR_SIZE; i++)
migrate_timer_list(new_base, old_base->tv1.vec + i);
for (i = 0; i < TVN_SIZE; i++) {
migrate_timer_list(new_base, old_base->tv5.vec + i);
}
- spin_unlock(&old_base->t_base.lock);
- spin_unlock(&new_base->t_base.lock);
+ spin_unlock(&old_base->lock);
+ spin_unlock(&new_base->lock);
local_irq_enable();
put_cpu_var(tvec_bases);
}
#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);
+ if (init_timers_cpu(cpu) < 0)
+ return NOTIFY_BAD;
break;
#ifdef CONFIG_HOTPLUG_CPU
case CPU_DEAD:
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());
+
+ BUG_ON(err == NOTIFY_BAD);
register_cpu_notifier(&timers_nb);
open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL);
}
#define INTERPOLATOR_ADJUST 65536
#define INTERPOLATOR_MAX_SKIP 10*INTERPOLATOR_ADJUST
-static void time_interpolator_update(long delta_nsec)
+void time_interpolator_update(long delta_nsec)
{
u64 counter;
unsigned long offset;
*/
if (jiffies % INTERPOLATOR_ADJUST == 0)
{
- if (time_interpolator->skips == 0 && time_interpolator->offset > TICK_NSEC)
+ if (time_interpolator->skips == 0 && time_interpolator->offset > tick_nsec)
time_interpolator->nsec_per_cyc--;
if (time_interpolator->ns_skipped > INTERPOLATOR_MAX_SKIP && time_interpolator->offset == 0)
time_interpolator->nsec_per_cyc++;
unsigned long flags;
/* Sanity check */
- if (ti->frequency == 0 || ti->mask == 0)
- BUG();
+ BUG_ON(ti->frequency == 0 || ti->mask == 0);
ti->nsec_per_cyc = ((u64)NSEC_PER_SEC << ti->shift) / ti->frequency;
spin_lock(&time_interpolator_lock);
git://git.onelab.eu / linux-2.6.git / blobdiff