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Subject[patch 21/21] Convert posix timers completely

- convert posix-timers.c to use hrtimers
- remove the now obsolete abslist code

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/linux/hrtimer.h | 7
include/linux/posix-timers.h | 37 --
include/linux/time.h | 3
kernel/posix-timers.c | 713 ++++++++-----------------------------------
4 files changed, 143 insertions(+), 617 deletions(-)
Index: linux-2.6.15-rc5/include/linux/posix-timers.h
===================================================================
--- linux-2.6.15-rc5.orig/include/linux/posix-timers.h
+++ linux-2.6.15-rc5/include/linux/posix-timers.h
@@ -51,12 +51,8 @@ struct k_itimer {
struct sigqueue *sigq; /* signal queue entry. */
union {
struct {
- struct timer_list timer;
- /* clock abs_timer_list: */
- struct list_head abs_timer_entry;
- /* wall_to_monotonic used when set: */
- struct timespec wall_to_prev;
- unsigned long incr; /* interval in jiffies */
+ struct hrtimer timer;
+ ktime_t interval;
} real;
struct cpu_timer_list cpu;
struct {
@@ -68,15 +64,9 @@ struct k_itimer {
} it;
};

-struct k_clock_abs {
- struct list_head list;
- spinlock_t lock;
-};
-
struct k_clock {
int res; /* in nanoseconds */
int (*clock_getres) (const clockid_t which_clock, struct timespec *tp);
- struct k_clock_abs *abs_struct;
int (*clock_set) (const clockid_t which_clock, struct timespec * tp);
int (*clock_get) (const clockid_t which_clock, struct timespec * tp);
int (*timer_create) (struct k_itimer *timer);
@@ -102,29 +92,6 @@ int do_posix_clock_nosettime(const clock
/* function to call to trigger timer event */
int posix_timer_event(struct k_itimer *timr, int si_private);

-struct now_struct {
- unsigned long jiffies;
-};
-
-#define posix_get_now(now) \
- do { (now)->jiffies = jiffies; } while (0)
-
-#define posix_time_before(timer, now) \
- time_before((timer)->expires, (now)->jiffies)
-
-#define posix_bump_timer(timr, now) \
- do { \
- long delta, orun; \
- \
- delta = (now).jiffies - (timr)->it.real.timer.expires; \
- if (delta >= 0) { \
- orun = 1 + (delta / (timr)->it.real.incr); \
- (timr)->it.real.timer.expires += \
- orun * (timr)->it.real.incr; \
- (timr)->it_overrun += orun; \
- } \
- } while (0)
-
int posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *ts);
int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *ts);
int posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *ts);
Index: linux-2.6.15-rc5/include/linux/time.h
===================================================================
--- linux-2.6.15-rc5.orig/include/linux/time.h
+++ linux-2.6.15-rc5/include/linux/time.h
@@ -73,8 +73,7 @@ struct timespec current_kernel_time(void
extern void do_gettimeofday(struct timeval *tv);
extern int do_settimeofday(struct timespec *tv);
extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
-extern void clock_was_set(void); // call whenever the clock is set
-extern int do_posix_clock_monotonic_gettime(struct timespec *tp);
+#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
extern long do_utimes(char __user *filename, struct timeval *times);
struct itimerval;
extern int do_setitimer(int which, struct itimerval *value,
Index: linux-2.6.15-rc5/kernel/posix-timers.c
===================================================================
--- linux-2.6.15-rc5.orig/kernel/posix-timers.c
+++ linux-2.6.15-rc5/kernel/posix-timers.c
@@ -35,7 +35,6 @@
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/time.h>
-#include <linux/calc64.h>

#include <asm/uaccess.h>
#include <asm/semaphore.h>
@@ -49,12 +48,6 @@
#include <linux/workqueue.h>
#include <linux/module.h>

-#define CLOCK_REALTIME_RES TICK_NSEC /* In nano seconds. */
-
-static inline u64 mpy_l_X_l_ll(unsigned long mpy1,unsigned long mpy2)
-{
- return (u64)mpy1 * mpy2;
-}
/*
* Management arrays for POSIX timers. Timers are kept in slab memory
* Timer ids are allocated by an external routine that keeps track of the
@@ -140,18 +133,18 @@ static DEFINE_SPINLOCK(idr_lock);
*/

static struct k_clock posix_clocks[MAX_CLOCKS];
+
/*
- * We only have one real clock that can be set so we need only one abs list,
- * even if we should want to have several clocks with differing resolutions.
+ * These ones are defined below.
*/
-static struct k_clock_abs abs_list = {.list = LIST_HEAD_INIT(abs_list.list),
- .lock = SPIN_LOCK_UNLOCKED};
+static int common_nsleep(const clockid_t, int flags, struct timespec *t,
+ struct timespec __user *rmtp);
+static void common_timer_get(struct k_itimer *, struct itimerspec *);
+static int common_timer_set(struct k_itimer *, int,
+ struct itimerspec *, struct itimerspec *);
+static int common_timer_del(struct k_itimer *timer);

-static void posix_timer_fn(unsigned long);
-static u64 do_posix_clock_monotonic_gettime_parts(
- struct timespec *tp, struct timespec *mo);
-int do_posix_clock_monotonic_gettime(struct timespec *tp);
-static int do_posix_clock_monotonic_get(const clockid_t, struct timespec *tp);
+static int posix_timer_fn(void *data);

static struct k_itimer *lock_timer(timer_t timer_id, unsigned long *flags);

@@ -184,10 +177,12 @@ static inline int common_clock_getres(co
return 0;
}

-static inline int common_clock_get(const clockid_t which_clock,
- struct timespec *tp)
+/*
+ * Get real time for posix timers
+ */
+static int common_clock_get(clockid_t which_clock, struct timespec *tp)
{
- getnstimeofday(tp);
+ ktime_get_real_ts(tp);
return 0;
}

@@ -199,25 +194,14 @@ static inline int common_clock_set(const

static inline int common_timer_create(struct k_itimer *new_timer)
{
- INIT_LIST_HEAD(&new_timer->it.real.abs_timer_entry);
- init_timer(&new_timer->it.real.timer);
- new_timer->it.real.timer.data = (unsigned long) new_timer;
+ hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock);
+ new_timer->it.real.timer.data = new_timer;
new_timer->it.real.timer.function = posix_timer_fn;
return 0;
}

/*
- * These ones are defined below.
- */
-static int common_nsleep(const clockid_t, int flags, struct timespec *t,
- struct timespec __user *rmtp);
-static void common_timer_get(struct k_itimer *, struct itimerspec *);
-static int common_timer_set(struct k_itimer *, int,
- struct itimerspec *, struct itimerspec *);
-static int common_timer_del(struct k_itimer *timer);
-
-/*
- * Return nonzero iff we know a priori this clockid_t value is bogus.
+ * Return nonzero if we know a priori this clockid_t value is bogus.
*/
static inline int invalid_clockid(const clockid_t which_clock)
{
@@ -227,26 +211,32 @@ static inline int invalid_clockid(const
return 1;
if (posix_clocks[which_clock].clock_getres != NULL)
return 0;
-#ifndef CLOCK_DISPATCH_DIRECT
if (posix_clocks[which_clock].res != 0)
return 0;
-#endif
return 1;
}

+/*
+ * Get monotonic time for posix timers
+ */
+static int posix_ktime_get_ts(clockid_t which_clock, struct timespec *tp)
+{
+ ktime_get_ts(tp);
+ return 0;
+}

/*
* Initialize everything, well, just everything in Posix clocks/timers ;)
*/
static __init int init_posix_timers(void)
{
- struct k_clock clock_realtime = {.res = CLOCK_REALTIME_RES,
- .abs_struct = &abs_list
+ struct k_clock clock_realtime = {
+ .clock_getres = hrtimer_get_res,
};
- struct k_clock clock_monotonic = {.res = CLOCK_REALTIME_RES,
- .abs_struct = NULL,
- .clock_get = do_posix_clock_monotonic_get,
- .clock_set = do_posix_clock_nosettime
+ struct k_clock clock_monotonic = {
+ .clock_getres = hrtimer_get_res,
+ .clock_get = posix_ktime_get_ts,
+ .clock_set = do_posix_clock_nosettime,
};

register_posix_clock(CLOCK_REALTIME, &clock_realtime);
@@ -260,117 +250,17 @@ static __init int init_posix_timers(void

__initcall(init_posix_timers);

-static void tstojiffie(struct timespec *tp, int res, u64 *jiff)
-{
- long sec = tp->tv_sec;
- long nsec = tp->tv_nsec + res - 1;
-
- if (nsec >= NSEC_PER_SEC) {
- sec++;
- nsec -= NSEC_PER_SEC;
- }
-
- /*
- * The scaling constants are defined in <linux/time.h>
- * The difference between there and here is that we do the
- * res rounding and compute a 64-bit result (well so does that
- * but it then throws away the high bits).
- */
- *jiff = (mpy_l_X_l_ll(sec, SEC_CONVERSION) +
- (mpy_l_X_l_ll(nsec, NSEC_CONVERSION) >>
- (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC;
-}
-
-/*
- * This function adjusts the timer as needed as a result of the clock
- * being set. It should only be called for absolute timers, and then
- * under the abs_list lock. It computes the time difference and sets
- * the new jiffies value in the timer. It also updates the timers
- * reference wall_to_monotonic value. It is complicated by the fact
- * that tstojiffies() only handles positive times and it needs to work
- * with both positive and negative times. Also, for negative offsets,
- * we need to defeat the res round up.
- *
- * Return is true if there is a new time, else false.
- */
-static long add_clockset_delta(struct k_itimer *timr,
- struct timespec *new_wall_to)
-{
- struct timespec delta;
- int sign = 0;
- u64 exp;
-
- set_normalized_timespec(&delta,
- new_wall_to->tv_sec -
- timr->it.real.wall_to_prev.tv_sec,
- new_wall_to->tv_nsec -
- timr->it.real.wall_to_prev.tv_nsec);
- if (likely(!(delta.tv_sec | delta.tv_nsec)))
- return 0;
- if (delta.tv_sec < 0) {
- set_normalized_timespec(&delta,
- -delta.tv_sec,
- 1 - delta.tv_nsec -
- posix_clocks[timr->it_clock].res);
- sign++;
- }
- tstojiffie(&delta, posix_clocks[timr->it_clock].res, &exp);
- timr->it.real.wall_to_prev = *new_wall_to;
- timr->it.real.timer.expires += (sign ? -exp : exp);
- return 1;
-}
-
-static void remove_from_abslist(struct k_itimer *timr)
-{
- if (!list_empty(&timr->it.real.abs_timer_entry)) {
- spin_lock(&abs_list.lock);
- list_del_init(&timr->it.real.abs_timer_entry);
- spin_unlock(&abs_list.lock);
- }
-}
-
static void schedule_next_timer(struct k_itimer *timr)
{
- struct timespec new_wall_to;
- struct now_struct now;
- unsigned long seq;
-
- /*
- * Set up the timer for the next interval (if there is one).
- * Note: this code uses the abs_timer_lock to protect
- * it.real.wall_to_prev and must hold it until exp is set, not exactly
- * obvious...
-
- * This function is used for CLOCK_REALTIME* and
- * CLOCK_MONOTONIC* timers. If we ever want to handle other
- * CLOCKs, the calling code (do_schedule_next_timer) would need
- * to pull the "clock" info from the timer and dispatch the
- * "other" CLOCKs "next timer" code (which, I suppose should
- * also be added to the k_clock structure).
- */
- if (!timr->it.real.incr)
+ if (timr->it.real.interval.tv64 == 0)
return;

- do {
- seq = read_seqbegin(&xtime_lock);
- new_wall_to = wall_to_monotonic;
- posix_get_now(&now);
- } while (read_seqretry(&xtime_lock, seq));
-
- if (!list_empty(&timr->it.real.abs_timer_entry)) {
- spin_lock(&abs_list.lock);
- add_clockset_delta(timr, &new_wall_to);
-
- posix_bump_timer(timr, now);
-
- spin_unlock(&abs_list.lock);
- } else {
- posix_bump_timer(timr, now);
- }
+ timr->it_overrun += hrtimer_forward(&timr->it.real.timer,
+ timr->it.real.interval);
timr->it_overrun_last = timr->it_overrun;
timr->it_overrun = -1;
++timr->it_requeue_pending;
- add_timer(&timr->it.real.timer);
+ hrtimer_restart(&timr->it.real.timer);
}

/*
@@ -391,31 +281,23 @@ void do_schedule_next_timer(struct sigin

timr = lock_timer(info->si_tid, &flags);

- if (!timr || timr->it_requeue_pending != info->si_sys_private)
- goto exit;
+ if (timr && timr->it_requeue_pending == info->si_sys_private) {
+ if (timr->it_clock < 0)
+ posix_cpu_timer_schedule(timr);
+ else
+ schedule_next_timer(timr);

- if (timr->it_clock < 0) /* CPU clock */
- posix_cpu_timer_schedule(timr);
- else
- schedule_next_timer(timr);
- info->si_overrun = timr->it_overrun_last;
-exit:
- if (timr)
- unlock_timer(timr, flags);
+ info->si_overrun = timr->it_overrun_last;
+ }
+
+ unlock_timer(timr, flags);
}

int posix_timer_event(struct k_itimer *timr,int si_private)
{
memset(&timr->sigq->info, 0, sizeof(siginfo_t));
timr->sigq->info.si_sys_private = si_private;
- /*
- * Send signal to the process that owns this timer.
-
- * This code assumes that all the possible abs_lists share the
- * same lock (there is only one list at this time). If this is
- * not the case, the CLOCK info would need to be used to find
- * the proper abs list lock.
- */
+ /* Send signal to the process that owns this timer.*/

timr->sigq->info.si_signo = timr->it_sigev_signo;
timr->sigq->info.si_errno = 0;
@@ -449,64 +331,35 @@ EXPORT_SYMBOL_GPL(posix_timer_event);

* This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
*/
-static void posix_timer_fn(unsigned long __data)
+static int posix_timer_fn(void *data)
{
- struct k_itimer *timr = (struct k_itimer *) __data;
+ struct k_itimer *timr = data;
unsigned long flags;
- unsigned long seq;
- struct timespec delta, new_wall_to;
- u64 exp = 0;
- int do_notify = 1;
+ int si_private = 0;
+ int ret = HRTIMER_NORESTART;

spin_lock_irqsave(&timr->it_lock, flags);
- if (!list_empty(&timr->it.real.abs_timer_entry)) {
- spin_lock(&abs_list.lock);
- do {
- seq = read_seqbegin(&xtime_lock);
- new_wall_to = wall_to_monotonic;
- } while (read_seqretry(&xtime_lock, seq));
- set_normalized_timespec(&delta,
- new_wall_to.tv_sec -
- timr->it.real.wall_to_prev.tv_sec,
- new_wall_to.tv_nsec -
- timr->it.real.wall_to_prev.tv_nsec);
- if (likely((delta.tv_sec | delta.tv_nsec ) == 0)) {
- /* do nothing, timer is on time */
- } else if (delta.tv_sec < 0) {
- /* do nothing, timer is already late */
- } else {
- /* timer is early due to a clock set */
- tstojiffie(&delta,
- posix_clocks[timr->it_clock].res,
- &exp);
- timr->it.real.wall_to_prev = new_wall_to;
- timr->it.real.timer.expires += exp;
- add_timer(&timr->it.real.timer);
- do_notify = 0;
- }
- spin_unlock(&abs_list.lock);

- }
- if (do_notify) {
- int si_private=0;
+ if (timr->it.real.interval.tv64 != 0)
+ si_private = ++timr->it_requeue_pending;

- if (timr->it.real.incr)
- si_private = ++timr->it_requeue_pending;
- else {
- remove_from_abslist(timr);
+ if (posix_timer_event(timr, si_private)) {
+ /*
+ * signal was not sent because of sig_ignor
+ * we will not get a call back to restart it AND
+ * it should be restarted.
+ */
+ if (timr->it.real.interval.tv64 != 0) {
+ timr->it_overrun +=
+ hrtimer_forward(&timr->it.real.timer,
+ timr->it.real.interval);
+ ret = HRTIMER_RESTART;
}
-
- if (posix_timer_event(timr, si_private))
- /*
- * signal was not sent because of sig_ignor
- * we will not get a call back to restart it AND
- * it should be restarted.
- */
- schedule_next_timer(timr);
}
- unlock_timer(timr, flags); /* hold thru abs lock to keep irq off */
-}

+ unlock_timer(timr, flags);
+ return ret;
+}

static inline struct task_struct * good_sigevent(sigevent_t * event)
{
@@ -597,8 +450,7 @@ sys_timer_create(const clockid_t which_c
goto out;
}
spin_lock_irq(&idr_lock);
- error = idr_get_new(&posix_timers_id,
- (void *) new_timer,
+ error = idr_get_new(&posix_timers_id, (void *) new_timer,
&new_timer_id);
spin_unlock_irq(&idr_lock);
if (error == -EAGAIN)
@@ -699,26 +551,6 @@ out:
}

/*
- * good_timespec
- *
- * This function checks the elements of a timespec structure.
- *
- * Arguments:
- * ts : Pointer to the timespec structure to check
- *
- * Return value:
- * If a NULL pointer was passed in, or the tv_nsec field was less than 0
- * or greater than NSEC_PER_SEC, or the tv_sec field was less than 0,
- * this function returns 0. Otherwise it returns 1.
- */
-static int good_timespec(const struct timespec *ts)
-{
- if ((!ts) || !timespec_valid(ts))
- return 0;
- return 1;
-}
-
-/*
* Locking issues: We need to protect the result of the id look up until
* we get the timer locked down so it is not deleted under us. The
* removal is done under the idr spinlock so we use that here to bridge
@@ -770,39 +602,39 @@ static struct k_itimer * lock_timer(time
static void
common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)
{
- unsigned long expires;
- struct now_struct now;
+ ktime_t remaining;
+ struct hrtimer *timer = &timr->it.real.timer;

- do
- expires = timr->it.real.timer.expires;
- while ((volatile long) (timr->it.real.timer.expires) != expires);
-
- posix_get_now(&now);
-
- if (expires &&
- ((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) &&
- !timr->it.real.incr &&
- posix_time_before(&timr->it.real.timer, &now))
- timr->it.real.timer.expires = expires = 0;
- if (expires) {
- if (timr->it_requeue_pending & REQUEUE_PENDING ||
- (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) {
- posix_bump_timer(timr, now);
- expires = timr->it.real.timer.expires;
- }
- else
- if (!timer_pending(&timr->it.real.timer))
- expires = 0;
- if (expires)
- expires -= now.jiffies;
- }
- jiffies_to_timespec(expires, &cur_setting->it_value);
- jiffies_to_timespec(timr->it.real.incr, &cur_setting->it_interval);
+ memset(cur_setting, 0, sizeof(struct itimerspec));
+ remaining = hrtimer_get_remaining(timer);

- if (cur_setting->it_value.tv_sec < 0) {
+ /* Time left ? or timer pending */
+ if (remaining.tv64 > 0 || hrtimer_active(timer))
+ goto calci;
+ /* interval timer ? */
+ if (timr->it.real.interval.tv64 == 0)
+ return;
+ /*
+ * When a requeue is pending or this is a SIGEV_NONE timer
+ * move the expiry time forward by intervals, so expiry is >
+ * now.
+ */
+ if (timr->it_requeue_pending & REQUEUE_PENDING ||
+ (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) {
+ timr->it_overrun +=
+ hrtimer_forward(timer, timr->it.real.interval);
+ remaining = hrtimer_get_remaining(timer);
+ }
+ calci:
+ /* interval timer ? */
+ if (timr->it.real.interval.tv64 != 0)
+ cur_setting->it_interval =
+ ktime_to_timespec(timr->it.real.interval);
+ /* Return 0 only, when the timer is expired and not pending */
+ if (remaining.tv64 <= 0)
cur_setting->it_value.tv_nsec = 1;
- cur_setting->it_value.tv_sec = 0;
- }
+ else
+ cur_setting->it_value = ktime_to_timespec(remaining);
}

/* Get the time remaining on a POSIX.1b interval timer. */
@@ -826,6 +658,7 @@ sys_timer_gettime(timer_t timer_id, stru

return 0;
}
+
/*
* Get the number of overruns of a POSIX.1b interval timer. This is to
* be the overrun of the timer last delivered. At the same time we are
@@ -835,7 +668,6 @@ sys_timer_gettime(timer_t timer_id, stru
* the call back to do_schedule_next_timer(). So all we need to do is
* to pick up the frozen overrun.
*/
-
asmlinkage long
sys_timer_getoverrun(timer_t timer_id)
{
@@ -852,84 +684,6 @@ sys_timer_getoverrun(timer_t timer_id)

return overrun;
}
-/*
- * Adjust for absolute time
- *
- * If absolute time is given and it is not CLOCK_MONOTONIC, we need to
- * adjust for the offset between the timer clock (CLOCK_MONOTONIC) and
- * what ever clock he is using.
- *
- * If it is relative time, we need to add the current (CLOCK_MONOTONIC)
- * time to it to get the proper time for the timer.
- */
-static int adjust_abs_time(struct k_clock *clock, struct timespec *tp,
- int abs, u64 *exp, struct timespec *wall_to)
-{
- struct timespec now;
- struct timespec oc = *tp;
- u64 jiffies_64_f;
- int rtn =0;
-
- if (abs) {
- /*
- * The mask pick up the 4 basic clocks
- */
- if (!((clock - &posix_clocks[0]) & ~CLOCKS_MASK)) {
- jiffies_64_f = do_posix_clock_monotonic_gettime_parts(
- &now, wall_to);
- /*
- * If we are doing a MONOTONIC clock
- */
- if((clock - &posix_clocks[0]) & CLOCKS_MONO){
- now.tv_sec += wall_to->tv_sec;
- now.tv_nsec += wall_to->tv_nsec;
- }
- } else {
- /*
- * Not one of the basic clocks
- */
- clock->clock_get(clock - posix_clocks, &now);
- jiffies_64_f = get_jiffies_64();
- }
- /*
- * Take away now to get delta and normalize
- */
- set_normalized_timespec(&oc, oc.tv_sec - now.tv_sec,
- oc.tv_nsec - now.tv_nsec);
- }else{
- jiffies_64_f = get_jiffies_64();
- }
- /*
- * Check if the requested time is prior to now (if so set now)
- */
- if (oc.tv_sec < 0)
- oc.tv_sec = oc.tv_nsec = 0;
-
- if (oc.tv_sec | oc.tv_nsec)
- set_normalized_timespec(&oc, oc.tv_sec,
- oc.tv_nsec + clock->res);
- tstojiffie(&oc, clock->res, exp);
-
- /*
- * Check if the requested time is more than the timer code
- * can handle (if so we error out but return the value too).
- */
- if (*exp > ((u64)MAX_JIFFY_OFFSET))
- /*
- * This is a considered response, not exactly in
- * line with the standard (in fact it is silent on
- * possible overflows). We assume such a large
- * value is ALMOST always a programming error and
- * try not to compound it by setting a really dumb
- * value.
- */
- rtn = -EINVAL;
- /*
- * return the actual jiffies expire time, full 64 bits
- */
- *exp += jiffies_64_f;
- return rtn;
-}

/* Set a POSIX.1b interval timer. */
/* timr->it_lock is taken. */
@@ -937,68 +691,48 @@ static inline int
common_timer_set(struct k_itimer *timr, int flags,
struct itimerspec *new_setting, struct itimerspec *old_setting)
{
- struct k_clock *clock = &posix_clocks[timr->it_clock];
- u64 expire_64;
+ struct hrtimer *timer = &timr->it.real.timer;

if (old_setting)
common_timer_get(timr, old_setting);

/* disable the timer */
- timr->it.real.incr = 0;
+ timr->it.real.interval.tv64 = 0;
/*
* careful here. If smp we could be in the "fire" routine which will
* be spinning as we hold the lock. But this is ONLY an SMP issue.
*/
- if (try_to_del_timer_sync(&timr->it.real.timer) < 0) {
-#ifdef CONFIG_SMP
- /*
- * It can only be active if on an other cpu. Since
- * we have cleared the interval stuff above, it should
- * clear once we release the spin lock. Of course once
- * we do that anything could happen, including the
- * complete melt down of the timer. So return with
- * a "retry" exit status.
- */
+ if (hrtimer_try_to_cancel(timer) < 0)
return TIMER_RETRY;
-#endif
- }
-
- remove_from_abslist(timr);

timr->it_requeue_pending = (timr->it_requeue_pending + 2) &
~REQUEUE_PENDING;
timr->it_overrun_last = 0;
- timr->it_overrun = -1;
- /*
- *switch off the timer when it_value is zero
- */
- if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec) {
- timr->it.real.timer.expires = 0;
- return 0;
- }

- if (adjust_abs_time(clock,
- &new_setting->it_value, flags & TIMER_ABSTIME,
- &expire_64, &(timr->it.real.wall_to_prev))) {
- return -EINVAL;
- }
- timr->it.real.timer.expires = (unsigned long)expire_64;
- tstojiffie(&new_setting->it_interval, clock->res, &expire_64);
- timr->it.real.incr = (unsigned long)expire_64;
+ /* switch off the timer when it_value is zero */
+ if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
+ return 0;

- /*
- * We do not even queue SIGEV_NONE timers! But we do put them
- * in the abs list so we can do that right.
+ /* Posix madness. Only absolute CLOCK_REALTIME timers
+ * are affected by clock sets. So we must reiniatilize
+ * the timer.
*/
- if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE))
- add_timer(&timr->it.real.timer);
+ if (timr->it_clock == CLOCK_REALTIME && (flags & TIMER_ABSTIME))
+ hrtimer_rebase(timer, CLOCK_REALTIME);
+ else
+ hrtimer_rebase(timer, CLOCK_MONOTONIC);

- if (flags & TIMER_ABSTIME && clock->abs_struct) {
- spin_lock(&clock->abs_struct->lock);
- list_add_tail(&(timr->it.real.abs_timer_entry),
- &(clock->abs_struct->list));
- spin_unlock(&clock->abs_struct->lock);
- }
+ timer->expires = timespec_to_ktime(new_setting->it_value);
+
+ /* Convert interval */
+ timr->it.real.interval = timespec_to_ktime(new_setting->it_interval);
+
+ /* SIGEV_NONE timers are not queued ! See common_timer_get */
+ if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE))
+ return 0;
+
+ hrtimer_start(timer, timer->expires, (flags & TIMER_ABSTIME) ?
+ HRTIMER_ABS : HRTIMER_REL);
return 0;
}

@@ -1020,8 +754,8 @@ sys_timer_settime(timer_t timer_id, int
if (copy_from_user(&new_spec, new_setting, sizeof (new_spec)))
return -EFAULT;

- if ((!good_timespec(&new_spec.it_interval)) ||
- (!good_timespec(&new_spec.it_value)))
+ if (!timespec_valid(&new_spec.it_interval) ||
+ !timespec_valid(&new_spec.it_value))
return -EINVAL;
retry:
timr = lock_timer(timer_id, &flag);
@@ -1037,8 +771,8 @@ retry:
goto retry;
}

- if (old_setting && !error && copy_to_user(old_setting,
- &old_spec, sizeof (old_spec)))
+ if (old_setting && !error &&
+ copy_to_user(old_setting, &old_spec, sizeof (old_spec)))
error = -EFAULT;

return error;
@@ -1046,24 +780,10 @@ retry:

static inline int common_timer_del(struct k_itimer *timer)
{
- timer->it.real.incr = 0;
+ timer->it.real.interval.tv64 = 0;

- if (try_to_del_timer_sync(&timer->it.real.timer) < 0) {
-#ifdef CONFIG_SMP
- /*
- * It can only be active if on an other cpu. Since
- * we have cleared the interval stuff above, it should
- * clear once we release the spin lock. Of course once
- * we do that anything could happen, including the
- * complete melt down of the timer. So return with
- * a "retry" exit status.
- */
+ if (hrtimer_try_to_cancel(&timer->it.real.timer) < 0)
return TIMER_RETRY;
-#endif
- }
-
- remove_from_abslist(timer);
-
return 0;
}

@@ -1079,24 +799,16 @@ sys_timer_delete(timer_t timer_id)
struct k_itimer *timer;
long flags;

-#ifdef CONFIG_SMP
- int error;
retry_delete:
-#endif
timer = lock_timer(timer_id, &flags);
if (!timer)
return -EINVAL;

-#ifdef CONFIG_SMP
- error = timer_delete_hook(timer);
-
- if (error == TIMER_RETRY) {
+ if (timer_delete_hook(timer) == TIMER_RETRY) {
unlock_timer(timer, flags);
goto retry_delete;
}
-#else
- timer_delete_hook(timer);
-#endif
+
spin_lock(&current->sighand->siglock);
list_del(&timer->list);
spin_unlock(&current->sighand->siglock);
@@ -1113,6 +825,7 @@ retry_delete:
release_posix_timer(timer, IT_ID_SET);
return 0;
}
+
/*
* return timer owned by the process, used by exit_itimers
*/
@@ -1120,22 +833,13 @@ static inline void itimer_delete(struct
{
unsigned long flags;

-#ifdef CONFIG_SMP
- int error;
retry_delete:
-#endif
spin_lock_irqsave(&timer->it_lock, flags);

-#ifdef CONFIG_SMP
- error = timer_delete_hook(timer);
-
- if (error == TIMER_RETRY) {
+ if (timer_delete_hook(timer) == TIMER_RETRY) {
unlock_timer(timer, flags);
goto retry_delete;
}
-#else
- timer_delete_hook(timer);
-#endif
list_del(&timer->list);
/*
* This keeps any tasks waiting on the spin lock from thinking
@@ -1164,57 +868,7 @@ void exit_itimers(struct signal_struct *
}
}

-/*
- * And now for the "clock" calls
- *
- * These functions are called both from timer functions (with the timer
- * spin_lock_irq() held and from clock calls with no locking. They must
- * use the save flags versions of locks.
- */
-
-/*
- * We do ticks here to avoid the irq lock ( they take sooo long).
- * The seqlock is great here. Since we a reader, we don't really care
- * if we are interrupted since we don't take lock that will stall us or
- * any other cpu. Voila, no irq lock is needed.
- *
- */
-
-static u64 do_posix_clock_monotonic_gettime_parts(
- struct timespec *tp, struct timespec *mo)
-{
- u64 jiff;
- unsigned int seq;
-
- do {
- seq = read_seqbegin(&xtime_lock);
- getnstimeofday(tp);
- *mo = wall_to_monotonic;
- jiff = jiffies_64;
-
- } while(read_seqretry(&xtime_lock, seq));
-
- return jiff;
-}
-
-static int do_posix_clock_monotonic_get(const clockid_t clock,
- struct timespec *tp)
-{
- struct timespec wall_to_mono;
-
- do_posix_clock_monotonic_gettime_parts(tp, &wall_to_mono);
-
- set_normalized_timespec(tp, tp->tv_sec + wall_to_mono.tv_sec,
- tp->tv_nsec + wall_to_mono.tv_nsec);
-
- return 0;
-}
-
-int do_posix_clock_monotonic_gettime(struct timespec *tp)
-{
- return do_posix_clock_monotonic_get(CLOCK_MONOTONIC, tp);
-}
-
+/* Not available / possible... functions */
int do_posix_clock_nosettime(const clockid_t clockid, struct timespec *tp)
{
return -EINVAL;
@@ -1288,107 +942,6 @@ sys_clock_getres(const clockid_t which_c
}

/*
- * The standard says that an absolute nanosleep call MUST wake up at
- * the requested time in spite of clock settings. Here is what we do:
- * For each nanosleep call that needs it (only absolute and not on
- * CLOCK_MONOTONIC* (as it can not be set)) we thread a little structure
- * into the "nanosleep_abs_list". All we need is the task_struct pointer.
- * When ever the clock is set we just wake up all those tasks. The rest
- * is done by the while loop in clock_nanosleep().
- *
- * On locking, clock_was_set() is called from update_wall_clock which
- * holds (or has held for it) a write_lock_irq( xtime_lock) and is
- * called from the timer bh code. Thus we need the irq save locks.
- *
- * Also, on the call from update_wall_clock, that is done as part of a
- * softirq thing. We don't want to delay the system that much (possibly
- * long list of timers to fix), so we defer that work to keventd.
- */
-
-static DECLARE_WAIT_QUEUE_HEAD(nanosleep_abs_wqueue);
-static DECLARE_WORK(clock_was_set_work, (void(*)(void*))clock_was_set, NULL);
-
-static DECLARE_MUTEX(clock_was_set_lock);
-
-void clock_was_set(void)
-{
- struct k_itimer *timr;
- struct timespec new_wall_to;
- LIST_HEAD(cws_list);
- unsigned long seq;
-
-
- if (unlikely(in_interrupt())) {
- schedule_work(&clock_was_set_work);
- return;
- }
- wake_up_all(&nanosleep_abs_wqueue);
-
- /*
- * Check if there exist TIMER_ABSTIME timers to correct.
- *
- * Notes on locking: This code is run in task context with irq
- * on. We CAN be interrupted! All other usage of the abs list
- * lock is under the timer lock which holds the irq lock as
- * well. We REALLY don't want to scan the whole list with the
- * interrupt system off, AND we would like a sequence lock on
- * this code as well. Since we assume that the clock will not
- * be set often, it seems ok to take and release the irq lock
- * for each timer. In fact add_timer will do this, so this is
- * not an issue. So we know when we are done, we will move the
- * whole list to a new location. Then as we process each entry,
- * we will move it to the actual list again. This way, when our
- * copy is empty, we are done. We are not all that concerned
- * about preemption so we will use a semaphore lock to protect
- * aginst reentry. This way we will not stall another
- * processor. It is possible that this may delay some timers
- * that should have expired, given the new clock, but even this
- * will be minimal as we will always update to the current time,
- * even if it was set by a task that is waiting for entry to
- * this code. Timers that expire too early will be caught by
- * the expire code and restarted.
-
- * Absolute timers that repeat are left in the abs list while
- * waiting for the task to pick up the signal. This means we
- * may find timers that are not in the "add_timer" list, but are
- * in the abs list. We do the same thing for these, save
- * putting them back in the "add_timer" list. (Note, these are
- * left in the abs list mainly to indicate that they are
- * ABSOLUTE timers, a fact that is used by the re-arm code, and
- * for which we have no other flag.)
-
- */
-
- down(&clock_was_set_lock);
- spin_lock_irq(&abs_list.lock);
- list_splice_init(&abs_list.list, &cws_list);
- spin_unlock_irq(&abs_list.lock);
- do {
- do {
- seq = read_seqbegin(&xtime_lock);
- new_wall_to = wall_to_monotonic;
- } while (read_seqretry(&xtime_lock, seq));
-
- spin_lock_irq(&abs_list.lock);
- if (list_empty(&cws_list)) {
- spin_unlock_irq(&abs_list.lock);
- break;
- }
- timr = list_entry(cws_list.next, struct k_itimer,
- it.real.abs_timer_entry);
-
- list_del_init(&timr->it.real.abs_timer_entry);
- if (add_clockset_delta(timr, &new_wall_to) &&
- del_timer(&timr->it.real.timer)) /* timer run yet? */
- add_timer(&timr->it.real.timer);
- list_add(&timr->it.real.abs_timer_entry, &abs_list.list);
- spin_unlock_irq(&abs_list.lock);
- } while (1);
-
- up(&clock_was_set_lock);
-}
-
-/*
* nanosleep for monotonic and realtime clocks
*/
static int common_nsleep(const clockid_t which_clock, int flags,
@@ -1401,7 +954,7 @@ static int common_nsleep(const clockid_t
case CLOCK_REALTIME:
/* Posix madness. Only absolute timers on clock realtime
are affected by clock set. */
- if (mode == HRTIMER_ABS)
+ if (mode != HRTIMER_ABS)
clockid = CLOCK_MONOTONIC;
case CLOCK_MONOTONIC:
break;
Index: linux-2.6.15-rc5/include/linux/hrtimer.h
===================================================================
--- linux-2.6.15-rc5.orig/include/linux/hrtimer.h
+++ linux-2.6.15-rc5/include/linux/hrtimer.h
@@ -93,6 +93,13 @@ struct hrtimer_base {
struct hrtimer *curr_timer;
};

+/*
+ * clock_was_set() is a NOP for non- high-resolution systems. The
+ * time-sorted order guarantees that a timer does not expire early and
+ * is expired in the next softirq when the clock was advanced.
+ */
+#define clock_was_set() do { } while (0)
+
/* Exported timer functions: */

/* Initialize timers: */
--

-
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