#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_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 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)
struct tvec_t_base_s {
spinlock_t lock;
- unsigned long timer_jiffies;
struct timer_list *running_timer;
+ unsigned long timer_jiffies;
tvec_root_t tv1;
tvec_t tv2;
tvec_t tv3;
typedef struct tvec_t_base_s tvec_base_t;
-static inline void set_running_timer(tvec_base_t *base,
- struct timer_list *timer)
+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)
{
-#ifdef CONFIG_SMP
- base->running_timer = timer;
-#endif
-}
+ 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;
-/* Fake initialization */
-static DEFINE_PER_CPU(tvec_base_t, tvec_bases) = { SPIN_LOCK_UNLOCKED };
+ /* now that we have rounded, subtract the extra skew again */
+ j -= cpu * 3;
-static void check_timer_failed(struct timer_list *timer)
+ 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)
{
- 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
+ * 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.
*/
- spin_lock_init(&timer->lock);
- timer->magic = TIMER_MAGIC;
+ 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);
-static inline void check_timer(struct timer_list *timer)
+/**
+ * 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)
{
- if (timer->magic != TIMER_MAGIC)
- check_timer_failed(timer);
+ 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->running_timer = timer;
+#endif
+}
static void internal_add_timer(tvec_base_t *base, struct timer_list *timer)
{
list_add_tail(&timer->entry, vec);
}
+/**
+ * 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 = __raw_get_cpu_var(tvec_bases);
+}
+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).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 tvec_base_t *lock_timer_base(struct timer_list *timer,
+ unsigned long *flags)
+ __acquires(timer->base->lock)
+{
+ tvec_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;
+ tvec_base_t *base, *new_base;
unsigned long flags;
int ret = 0;
BUG_ON(!timer->function);
- check_timer(timer);
+ base = lock_timer_base(timer, &flags);
- spin_lock_irqsave(&timer->lock, flags);
- new_base = &__get_cpu_var(tvec_bases);
-repeat:
- old_base = timer->base;
+ if (timer_pending(timer)) {
+ detach_timer(timer, 0);
+ ret = 1;
+ }
- /*
- * 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);
- }
+ new_base = __get_cpu_var(tvec_bases);
+
+ if (base != new_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 (likely(base->running_timer != timer)) {
+ /* See the comment in lock_timer_base() */
+ timer->base = NULL;
+ spin_unlock(&base->lock);
+ base = new_base;
+ spin_lock(&base->lock);
+ timer->base = 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);
+ 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);
-
- check_timer(timer);
+ BUG_ON(timer_pending(timer) || !timer->function);
spin_lock_irqsave(&base->lock, flags);
- internal_add_timer(base, timer);
timer->base = base;
+ internal_add_timer(base, timer);
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)
{
BUG_ON(!timer->function);
- check_timer(timer);
-
/*
* This is a common optimization triggered by the
* networking code - if the timer is re-modified
EXPORT_SYMBOL(mod_timer);
-/***
+/**
* del_timer - deactive a timer.
* @timer: the timer to be deactivated
*
*/
int del_timer(struct timer_list *timer)
{
- unsigned long flags;
tvec_base_t *base;
+ unsigned long flags;
+ int ret = 0;
- check_timer(timer);
-
-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.
+/**
+ * try_to_del_timer_sync - Try to deactivate a timer
+ * @timer: timer do del
*
- * 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;
+ 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;
+ cpu_relax();
}
-
- 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)
{
/* 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);
- 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->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);
-repeat:
- if (!list_empty(head)) {
+ ++base->timer_jiffies;
+ list_replace_init(base->tv1.vec + index, &work_list);
+ 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;
+ detach_timer(timer, 1);
spin_unlock_irq(&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;
}
}
set_running_timer(base, NULL);
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;
- base = &__get_cpu_var(tvec_bases);
+ 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);
expires = base->timer_jiffies + (LONG_MAX >> 1);
- list = 0;
+ list = NULL;
/* Look for timer events in tv1. */
j = base->timer_jiffies & TVR_MASK;
}
}
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;
+
return expires;
}
#endif
/******************************************************************/
-/*
- * 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) */
-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) */
-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)
-{
- long ltemp;
-
- /* Bump the maxerror field */
- time_maxerror += time_tolerance >> SHIFT_USEC;
- if ( time_maxerror > NTP_PHASE_LIMIT ) {
- time_maxerror = NTP_PHASE_LIMIT;
- time_status |= STA_UNSYNC;
- }
-
- /*
- * Leap second processing. If in leap-insert state at
- * the end of the day, the system clock is set back one
- * second; if in leap-delete state, the system clock is
- * set ahead one second. The microtime() routine or
- * external clock driver will insure that reported time
- * is always monotonic. The ugly divides should be
- * replaced.
- */
- switch (time_state) {
-
- case TIME_OK:
- if (time_status & STA_INS)
- time_state = TIME_INS;
- else if (time_status & STA_DEL)
- time_state = TIME_DEL;
- break;
-
- case TIME_INS:
- if (xtime.tv_sec % 86400 == 0) {
- xtime.tv_sec--;
- wall_to_monotonic.tv_sec++;
- /* The timer interpolator will make time change gradually instead
- * of an immediate jump by one second.
- */
- time_interpolator_update(-NSEC_PER_SEC);
- time_state = TIME_OOP;
- clock_was_set();
- printk(KERN_NOTICE "Clock: inserting leap second 23:59:60 UTC\n");
- }
- break;
-
- case TIME_DEL:
- if ((xtime.tv_sec + 1) % 86400 == 0) {
- xtime.tv_sec++;
- wall_to_monotonic.tv_sec--;
- /* Use of time interpolator for a gradual change of time */
- time_interpolator_update(NSEC_PER_SEC);
- time_state = TIME_WAIT;
- clock_was_set();
- printk(KERN_NOTICE "Clock: deleting leap second 23:59:59 UTC\n");
+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();
}
- 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;
- #if SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE > 0
- time_adj = -ltemp << (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE);
- #else
- time_adj = -ltemp >> (SHIFT_HZ + SHIFT_UPDATE - SHIFT_SCALE);
- #endif
- } else {
- ltemp = time_offset;
- if (!(time_status & STA_FLL))
- ltemp >>= SHIFT_KG + time_constant;
- if (ltemp > (MAXPHASE / MINSEC) << SHIFT_UPDATE)
- ltemp = (MAXPHASE / MINSEC) << SHIFT_UPDATE;
- time_offset -= ltemp;
- #if SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE > 0
- time_adj = ltemp << (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE);
- #else
- time_adj = ltemp >> (SHIFT_HZ + SHIFT_UPDATE - SHIFT_SCALE);
- #endif
- }
-
- /*
- * Compute the frequency estimate and additional phase
- * adjustment due to frequency error for the next
- * second. When the PPS signal is engaged, gnaw on the
- * watchdog counter and update the frequency computed by
- * the pll and the PPS signal.
- */
- pps_valid++;
- if (pps_valid == PPS_VALID) { /* PPS signal lost */
- pps_jitter = MAXTIME;
- pps_stabil = MAXFREQ;
- time_status &= ~(STA_PPSSIGNAL | STA_PPSJITTER |
- STA_PPSWANDER | STA_PPSERROR);
- }
- ltemp = time_freq + pps_freq;
- if (ltemp < 0)
- time_adj -= -ltemp >>
- (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE);
- else
- time_adj += ltemp >>
- (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE);
-
-#if HZ == 100
- /* Compensate for (HZ==100) != (1 << SHIFT_HZ).
- * Add 25% and 3.125% to get 128.125; => only 0.125% error (p. 14)
- */
- if (time_adj < 0)
- time_adj -= (-time_adj >> 2) + (-time_adj >> 5);
- else
- time_adj += (time_adj >> 2) + (time_adj >> 5);
-#endif
-#if HZ == 1000
- /* Compensate for (HZ==1000) != (1 << SHIFT_HZ).
- * Add 1.5625% and 0.78125% to get 1023.4375; => only 0.05% error (p. 14)
- */
- if (time_adj < 0)
- time_adj -= (-time_adj >> 6) + (-time_adj >> 7);
- else
- time_adj += (time_adj >> 6) + (time_adj >> 7);
+ 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;
}
-/* in the NTP reference this is called "hardclock()" */
-static void update_wall_time_one_tick(void)
-{
- long time_adjust_step, delta_nsec;
-
- if ( (time_adjust_step = time_adjust) != 0 ) {
- /* We are doing an adjtime thing.
- *
- * Prepare time_adjust_step to be within bounds.
- * Note that a positive time_adjust means we want the clock
- * to run faster.
- *
- * Limit the amount of the step to be in the range
- * -tickadj .. +tickadj
- */
- if (time_adjust > tickadj)
- time_adjust_step = tickadj;
- else if (time_adjust < -tickadj)
- time_adjust_step = -tickadj;
-
- /* Reduce by this step the amount of time left */
- time_adjust -= time_adjust_step;
- }
- delta_nsec = tick_nsec + time_adjust_step * 1000;
+/*
+ * timekeeping_init - Initializes the clocksource and common timekeeping values
+ */
+void __init timekeeping_init(void)
+{
+ unsigned long flags;
+
+ 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;
+}
+
+/* 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;
+
/*
- * 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) {
- long ltemp = -time_phase >> (SHIFT_SCALE - 10);
- time_phase += ltemp << (SHIFT_SCALE - 10);
- delta_nsec -= ltemp;
- }
- else if (time_phase >= FINENSEC) {
- long ltemp = time_phase >> (SHIFT_SCALE - 10);
- time_phase -= ltemp << (SHIFT_SCALE - 10);
- delta_nsec += ltemp;
- }
- xtime.tv_nsec += delta_nsec;
- time_interpolator_update(delta_nsec);
+ 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;
}
/*
- * 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
+ * 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.
*/
-static void update_wall_time(unsigned long ticks)
+static void clocksource_adjust(struct clocksource *clock, s64 offset)
{
- do {
- ticks--;
- update_wall_time_one_tick();
- if (xtime.tv_nsec >= 1000000000) {
- xtime.tv_nsec -= 1000000000;
+ 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;
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);
+ }
}
/*
if (rcu_pending(cpu))
rcu_check_callbacks(cpu, user_tick);
scheduler_tick();
+ run_posix_cpu_timers(p);
}
/*
*/
static unsigned long count_active_tasks(void)
{
- return (nr_running() + nr_uninterruptible()) * FIXED_1;
+ return nr_active() * FIXED_1;
}
/*
*/
unsigned long avenrun[3];
+EXPORT_SYMBOL(avenrun);
+
/*
* calc_load - given tick count, update the avenrun load estimates.
* This is called while holding a write_lock on xtime_lock.
static 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))
__run_timers(base);
}
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++;
- update_times();
+ 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
-#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 ->parent is not SMP-safe, it could
+ * change from under us. However, we can use a stale
+ * value of ->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;
- /*
- * 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;
- }
+ rcu_read_lock();
+ pid = rcu_dereference(current->parent)->tgid;
+ rcu_read_unlock();
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 */
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;
}
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;
}
-/*
+/**
* sys_sysinfo - fill in sysinfo struct
+ * @info: pointer to buffer to fill
*/
asmlinkage long sys_sysinfo(struct sysinfo __user *info)
{
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);
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;
-
- base = &per_cpu(tvec_bases, cpu);
+ 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);
+
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
-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);
- internal_add_timer(new_base, timer);
+ detach_timer(timer, 0);
timer->base = new_base;
- spin_unlock(&timer->lock);
+ internal_add_timer(new_base, timer);
}
- return 1;
}
static void __devinit migrate_timers(int cpu)
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();
-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->lock);
+ spin_lock(&old_base->lock);
+
+ BUG_ON(old_base->running_timer);
- if (old_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;
+ 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->lock);
spin_unlock(&new_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 */
-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);
}
#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
#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 (!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;
*/
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);
{
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