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[PATCH] hrtimer: 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>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Thomas Gleixner 2006-01-09 20:52:38 -08:00 committed by Linus Torvalds
parent 97735f25d2
commit becf8b5d00
5 changed files with 149 additions and 622 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
arch/um/kernel/time.c
View File

@ -99,7 +99,8 @@ void uml_idle_timer(void)
set_interval(ITIMER_REAL); set_interval(ITIMER_REAL);
} }
extern int do_posix_clock_monotonic_gettime(struct timespec *tp); extern void ktime_get_ts(struct timespec *ts);
#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
void time_init(void) void time_init(void)
{ {
@ -114,8 +115,8 @@ void time_init(void)
wall_to_monotonic.tv_nsec = -now.tv_nsec; wall_to_monotonic.tv_nsec = -now.tv_nsec;
} }
/* Declared in linux/time.h, which can't be included here */ /* Defined in linux/ktimer.h, which can't be included here */
extern void clock_was_set(void); #define clock_was_set() do { } while (0)
void do_gettimeofday(struct timeval *tv) void do_gettimeofday(struct timeval *tv)
{ {

7
include/linux/hrtimer.h
View File

@ -93,6 +93,13 @@ struct hrtimer_base {
struct hrtimer *curr_timer; 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: */ /* Exported timer functions: */
/* Initialize timers: */ /* Initialize timers: */

37
include/linux/posix-timers.h
View File

@ -51,12 +51,8 @@ struct k_itimer {
struct sigqueue *sigq; /* signal queue entry. */ struct sigqueue *sigq; /* signal queue entry. */
union { union {
struct { struct {
struct timer_list timer; struct hrtimer timer;
/* clock abs_timer_list: */ ktime_t interval;
struct list_head abs_timer_entry;
/* wall_to_monotonic used when set: */
struct timespec wall_to_prev;
unsigned long incr; /* interval in jiffies */
} real; } real;
struct cpu_timer_list cpu; struct cpu_timer_list cpu;
struct { struct {
@ -68,15 +64,9 @@ struct k_itimer {
} it; } it;
}; };
struct k_clock_abs {
struct list_head list;
spinlock_t lock;
};
struct k_clock { struct k_clock {
int res; /* in nanoseconds */ int res; /* in nanoseconds */
int (*clock_getres) (const clockid_t which_clock, struct timespec *tp); 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_set) (const clockid_t which_clock, struct timespec * tp);
int (*clock_get) (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); int (*timer_create) (struct k_itimer *timer);
@ -102,29 +92,6 @@ int do_posix_clock_nosettime(const clockid_t, struct timespec *tp);
/* function to call to trigger timer event */ /* function to call to trigger timer event */
int posix_timer_event(struct k_itimer *timr, int si_private); 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_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_get(const clockid_t which_clock, struct timespec *ts);
int posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *ts); int posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *ts);

3
include/linux/time.h
View File

@ -73,8 +73,7 @@ struct timespec current_kernel_time(void);
extern void do_gettimeofday(struct timeval *tv); extern void do_gettimeofday(struct timeval *tv);
extern int do_settimeofday(struct timespec *tv); extern int do_settimeofday(struct timespec *tv);
extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz); extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
extern void clock_was_set(void); // call whenever the clock is set #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
extern int do_posix_clock_monotonic_gettime(struct timespec *tp);
extern long do_utimes(char __user *filename, struct timeval *times); extern long do_utimes(char __user *filename, struct timeval *times);
struct itimerval; struct itimerval;
extern int do_setitimer(int which, struct itimerval *value, extern int do_setitimer(int which, struct itimerval *value,

717
kernel/posix-timers.c
View File

@ -35,7 +35,6 @@
#include <linux/interrupt.h> #include <linux/interrupt.h>
#include <linux/slab.h> #include <linux/slab.h>
#include <linux/time.h> #include <linux/time.h>
#include <linux/calc64.h>
#include <asm/uaccess.h> #include <asm/uaccess.h>
#include <asm/semaphore.h> #include <asm/semaphore.h>
@ -49,12 +48,6 @@
#include <linux/workqueue.h> #include <linux/workqueue.h>
#include <linux/module.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 * Management arrays for POSIX timers. Timers are kept in slab memory
* Timer ids are allocated by an external routine that keeps track of the * 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]; 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.
*/
static struct k_clock_abs abs_list = {.list = LIST_HEAD_INIT(abs_list.list),
.lock = SPIN_LOCK_UNLOCKED};
static void posix_timer_fn(unsigned long); /*
static u64 do_posix_clock_monotonic_gettime_parts( * These ones are defined below.
struct timespec *tp, struct timespec *mo); */
int do_posix_clock_monotonic_gettime(struct timespec *tp); static int common_nsleep(const clockid_t, int flags, struct timespec *t,
static int do_posix_clock_monotonic_get(const clockid_t, struct timespec *tp); 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 int posix_timer_fn(void *data);
static struct k_itimer *lock_timer(timer_t timer_id, unsigned long *flags); static struct k_itimer *lock_timer(timer_t timer_id, unsigned long *flags);
@ -184,10 +177,12 @@ static inline int common_clock_getres(const clockid_t which_clock,
return 0; 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; return 0;
} }
@ -199,25 +194,14 @@ static inline int common_clock_set(const clockid_t which_clock,
static inline int common_timer_create(struct k_itimer *new_timer) static inline int common_timer_create(struct k_itimer *new_timer)
{ {
INIT_LIST_HEAD(&new_timer->it.real.abs_timer_entry); hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock);
init_timer(&new_timer->it.real.timer); new_timer->it.real.timer.data = new_timer;
new_timer->it.real.timer.data = (unsigned long) new_timer;
new_timer->it.real.timer.function = posix_timer_fn; new_timer->it.real.timer.function = posix_timer_fn;
return 0; return 0;
} }
/* /*
* These ones are defined below. * Return nonzero if we know a priori this clockid_t value is bogus.
*/
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.
*/ */
static inline int invalid_clockid(const clockid_t which_clock) static inline int invalid_clockid(const clockid_t which_clock)
{ {
@ -227,26 +211,32 @@ static inline int invalid_clockid(const clockid_t which_clock)
return 1; return 1;
if (posix_clocks[which_clock].clock_getres != NULL) if (posix_clocks[which_clock].clock_getres != NULL)
return 0; return 0;
#ifndef CLOCK_DISPATCH_DIRECT
if (posix_clocks[which_clock].res != 0) if (posix_clocks[which_clock].res != 0)
return 0; return 0;
#endif
return 1; 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 ;) * Initialize everything, well, just everything in Posix clocks/timers ;)
*/ */
static __init int init_posix_timers(void) static __init int init_posix_timers(void)
{ {
struct k_clock clock_realtime = {.res = CLOCK_REALTIME_RES, struct k_clock clock_realtime = {
.abs_struct = &abs_list .clock_getres = hrtimer_get_res,
}; };
struct k_clock clock_monotonic = {.res = CLOCK_REALTIME_RES, struct k_clock clock_monotonic = {
.abs_struct = NULL, .clock_getres = hrtimer_get_res,
.clock_get = do_posix_clock_monotonic_get, .clock_get = posix_ktime_get_ts,
.clock_set = do_posix_clock_nosettime .clock_set = do_posix_clock_nosettime,
}; };
register_posix_clock(CLOCK_REALTIME, &clock_realtime); register_posix_clock(CLOCK_REALTIME, &clock_realtime);
@ -260,117 +250,17 @@ static __init int init_posix_timers(void)
__initcall(init_posix_timers); __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) static void schedule_next_timer(struct k_itimer *timr)
{ {
struct timespec new_wall_to; if (timr->it.real.interval.tv64 == 0)
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)
return; return;
do { timr->it_overrun += hrtimer_forward(&timr->it.real.timer,
seq = read_seqbegin(&xtime_lock); timr->it.real.interval);
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_last = timr->it_overrun; timr->it_overrun_last = timr->it_overrun;
timr->it_overrun = -1; timr->it_overrun = -1;
++timr->it_requeue_pending; ++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 siginfo *info)
timr = lock_timer(info->si_tid, &flags); timr = lock_timer(info->si_tid, &flags);
if (!timr || timr->it_requeue_pending != info->si_sys_private) if (timr && timr->it_requeue_pending == info->si_sys_private) {
goto exit; if (timr->it_clock < 0)
posix_cpu_timer_schedule(timr);
else
schedule_next_timer(timr);
if (timr->it_clock < 0) /* CPU clock */ info->si_overrun = timr->it_overrun_last;
posix_cpu_timer_schedule(timr); }
else
schedule_next_timer(timr); unlock_timer(timr, flags);
info->si_overrun = timr->it_overrun_last;
exit:
if (timr)
unlock_timer(timr, flags);
} }
int posix_timer_event(struct k_itimer *timr,int si_private) int posix_timer_event(struct k_itimer *timr,int si_private)
{ {
memset(&timr->sigq->info, 0, sizeof(siginfo_t)); memset(&timr->sigq->info, 0, sizeof(siginfo_t));
timr->sigq->info.si_sys_private = si_private; timr->sigq->info.si_sys_private = si_private;
/* /* Send signal to the process that owns this timer.*/
* 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.
*/
timr->sigq->info.si_signo = timr->it_sigev_signo; timr->sigq->info.si_signo = timr->it_sigev_signo;
timr->sigq->info.si_errno = 0; timr->sigq->info.si_errno = 0;
@ -449,65 +331,36 @@ EXPORT_SYMBOL_GPL(posix_timer_event);
* This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers. * 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 flags;
unsigned long seq; int si_private = 0;
struct timespec delta, new_wall_to; int ret = HRTIMER_NORESTART;
u64 exp = 0;
int do_notify = 1;
spin_lock_irqsave(&timr->it_lock, flags); spin_lock_irqsave(&timr->it_lock, flags);
if (!list_empty(&timr->it.real.abs_timer_entry)) {
spin_lock(&abs_list.lock); if (timr->it.real.interval.tv64 != 0)
do { si_private = ++timr->it_requeue_pending;
seq = read_seqbegin(&xtime_lock);
new_wall_to = wall_to_monotonic; if (posix_timer_event(timr, si_private)) {
} while (read_seqretry(&xtime_lock, seq)); /*
set_normalized_timespec(&delta, * signal was not sent because of sig_ignor
new_wall_to.tv_sec - * we will not get a call back to restart it AND
timr->it.real.wall_to_prev.tv_sec, * it should be restarted.
new_wall_to.tv_nsec - */
timr->it.real.wall_to_prev.tv_nsec); if (timr->it.real.interval.tv64 != 0) {
if (likely((delta.tv_sec | delta.tv_nsec ) == 0)) { timr->it_overrun +=
/* do nothing, timer is on time */ hrtimer_forward(&timr->it.real.timer,
} else if (delta.tv_sec < 0) { timr->it.real.interval);
/* do nothing, timer is already late */ ret = HRTIMER_RESTART;
} 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.incr) unlock_timer(timr, flags);
si_private = ++timr->it_requeue_pending; return ret;
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.
*/
schedule_next_timer(timr);
}
unlock_timer(timr, flags); /* hold thru abs lock to keep irq off */
} }
static inline struct task_struct * good_sigevent(sigevent_t * event) static inline struct task_struct * good_sigevent(sigevent_t * event)
{ {
struct task_struct *rtn = current->group_leader; struct task_struct *rtn = current->group_leader;
@ -597,8 +450,7 @@ sys_timer_create(const clockid_t which_clock,
goto out; goto out;
} }
spin_lock_irq(&idr_lock); spin_lock_irq(&idr_lock);
error = idr_get_new(&posix_timers_id, error = idr_get_new(&posix_timers_id, (void *) new_timer,
(void *) new_timer,
&new_timer_id); &new_timer_id);
spin_unlock_irq(&idr_lock); spin_unlock_irq(&idr_lock);
if (error == -EAGAIN) if (error == -EAGAIN)
@ -698,26 +550,6 @@ sys_timer_create(const clockid_t which_clock,
return error; return error;
} }
/*
* 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 * 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 * we get the timer locked down so it is not deleted under us. The
@ -770,39 +602,39 @@ static struct k_itimer * lock_timer(timer_t timer_id, unsigned long *flags)
static void static void
common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting) common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)
{ {
unsigned long expires; ktime_t remaining;
struct now_struct now; struct hrtimer *timer = &timr->it.real.timer;
do memset(cur_setting, 0, sizeof(struct itimerspec));
expires = timr->it.real.timer.expires; remaining = hrtimer_get_remaining(timer);
while ((volatile long) (timr->it.real.timer.expires) != expires);
posix_get_now(&now); /* Time left ? or timer pending */
if (remaining.tv64 > 0 || hrtimer_active(timer))
if (expires && goto calci;
((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) && /* interval timer ? */
!timr->it.real.incr && if (timr->it.real.interval.tv64 == 0)
posix_time_before(&timr->it.real.timer, &now)) return;
timr->it.real.timer.expires = expires = 0; /*
if (expires) { * When a requeue is pending or this is a SIGEV_NONE timer
if (timr->it_requeue_pending & REQUEUE_PENDING || * move the expiry time forward by intervals, so expiry is >
(timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) { * now.
posix_bump_timer(timr, now); */
expires = timr->it.real.timer.expires; if (timr->it_requeue_pending & REQUEUE_PENDING ||
} (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) {
else timr->it_overrun +=
if (!timer_pending(&timr->it.real.timer)) hrtimer_forward(timer, timr->it.real.interval);
expires = 0; remaining = hrtimer_get_remaining(timer);
if (expires)
expires -= now.jiffies;
} }
jiffies_to_timespec(expires, &cur_setting->it_value); calci:
jiffies_to_timespec(timr->it.real.incr, &cur_setting->it_interval); /* interval timer ? */
if (timr->it.real.interval.tv64 != 0)
if (cur_setting->it_value.tv_sec < 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_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. */ /* Get the time remaining on a POSIX.1b interval timer. */
@ -826,6 +658,7 @@ sys_timer_gettime(timer_t timer_id, struct itimerspec __user *setting)
return 0; return 0;
} }
/* /*
* Get the number of overruns of a POSIX.1b interval timer. This is to * 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 * 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, struct itimerspec __user *setting)
* the call back to do_schedule_next_timer(). So all we need to do is * the call back to do_schedule_next_timer(). So all we need to do is
* to pick up the frozen overrun. * to pick up the frozen overrun.
*/ */
asmlinkage long asmlinkage long
sys_timer_getoverrun(timer_t timer_id) sys_timer_getoverrun(timer_t timer_id)
{ {
@ -852,84 +684,6 @@ sys_timer_getoverrun(timer_t timer_id)
return overrun; 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. */ /* Set a POSIX.1b interval timer. */
/* timr->it_lock is taken. */ /* timr->it_lock is taken. */
@ -937,68 +691,48 @@ static inline int
common_timer_set(struct k_itimer *timr, int flags, common_timer_set(struct k_itimer *timr, int flags,
struct itimerspec *new_setting, struct itimerspec *old_setting) struct itimerspec *new_setting, struct itimerspec *old_setting)
{ {
struct k_clock *clock = &posix_clocks[timr->it_clock]; struct hrtimer *timer = &timr->it.real.timer;
u64 expire_64;
if (old_setting) if (old_setting)
common_timer_get(timr, old_setting); common_timer_get(timr, old_setting);
/* disable the timer */ /* 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 * 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. * 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) { if (hrtimer_try_to_cancel(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.
*/
return TIMER_RETRY; return TIMER_RETRY;
#endif
}
remove_from_abslist(timr);
timr->it_requeue_pending = (timr->it_requeue_pending + 2) & timr->it_requeue_pending = (timr->it_requeue_pending + 2) &
~REQUEUE_PENDING; ~REQUEUE_PENDING;
timr->it_overrun_last = 0; timr->it_overrun_last = 0;
timr->it_overrun = -1;
/* /* switch off the timer when it_value is zero */
*switch off the timer when it_value is zero if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec)
*/
if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec) {
timr->it.real.timer.expires = 0;
return 0; return 0;
}
if (adjust_abs_time(clock, /* Posix madness. Only absolute CLOCK_REALTIME timers
&new_setting->it_value, flags & TIMER_ABSTIME, * are affected by clock sets. So we must reiniatilize
&expire_64, &(timr->it.real.wall_to_prev))) { * the timer.
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;
/*
* We do not even queue SIGEV_NONE timers! But we do put them
* in the abs list so we can do that right.
*/ */
if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)) if (timr->it_clock == CLOCK_REALTIME && (flags & TIMER_ABSTIME))
add_timer(&timr->it.real.timer); hrtimer_rebase(timer, CLOCK_REALTIME);
else
hrtimer_rebase(timer, CLOCK_MONOTONIC);
if (flags & TIMER_ABSTIME && clock->abs_struct) { timer->expires = timespec_to_ktime(new_setting->it_value);
spin_lock(&clock->abs_struct->lock);
list_add_tail(&(timr->it.real.abs_timer_entry), /* Convert interval */
&(clock->abs_struct->list)); timr->it.real.interval = timespec_to_ktime(new_setting->it_interval);
spin_unlock(&clock->abs_struct->lock);
} /* 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; return 0;
} }
@ -1020,8 +754,8 @@ sys_timer_settime(timer_t timer_id, int flags,
if (copy_from_user(&new_spec, new_setting, sizeof (new_spec))) if (copy_from_user(&new_spec, new_setting, sizeof (new_spec)))
return -EFAULT; return -EFAULT;
if ((!good_timespec(&new_spec.it_interval)) || if (!timespec_valid(&new_spec.it_interval) ||
(!good_timespec(&new_spec.it_value))) !timespec_valid(&new_spec.it_value))
return -EINVAL; return -EINVAL;
retry: retry:
timr = lock_timer(timer_id, &flag); timr = lock_timer(timer_id, &flag);
@ -1037,8 +771,8 @@ sys_timer_settime(timer_t timer_id, int flags,
goto retry; goto retry;
} }
if (old_setting && !error && copy_to_user(old_setting, if (old_setting && !error &&
&old_spec, sizeof (old_spec))) copy_to_user(old_setting, &old_spec, sizeof (old_spec)))
error = -EFAULT; error = -EFAULT;
return error; return error;
@ -1046,24 +780,10 @@ sys_timer_settime(timer_t timer_id, int flags,
static inline int common_timer_del(struct k_itimer *timer) 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) { if (hrtimer_try_to_cancel(&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.
*/
return TIMER_RETRY; return TIMER_RETRY;
#endif
}
remove_from_abslist(timer);
return 0; return 0;
} }
@ -1079,24 +799,16 @@ sys_timer_delete(timer_t timer_id)
struct k_itimer *timer; struct k_itimer *timer;
long flags; long flags;
#ifdef CONFIG_SMP
int error;
retry_delete: retry_delete:
#endif
timer = lock_timer(timer_id, &flags); timer = lock_timer(timer_id, &flags);
if (!timer) if (!timer)
return -EINVAL; return -EINVAL;
#ifdef CONFIG_SMP if (timer_delete_hook(timer) == TIMER_RETRY) {
error = timer_delete_hook(timer);
if (error == TIMER_RETRY) {
unlock_timer(timer, flags); unlock_timer(timer, flags);
goto retry_delete; goto retry_delete;
} }
#else
timer_delete_hook(timer);
#endif
spin_lock(&current->sighand->siglock); spin_lock(&current->sighand->siglock);
list_del(&timer->list); list_del(&timer->list);
spin_unlock(&current->sighand->siglock); spin_unlock(&current->sighand->siglock);
@ -1113,6 +825,7 @@ sys_timer_delete(timer_t timer_id)
release_posix_timer(timer, IT_ID_SET); release_posix_timer(timer, IT_ID_SET);
return 0; return 0;
} }
/* /*
* return timer owned by the process, used by exit_itimers * return timer owned by the process, used by exit_itimers
*/ */
@ -1120,22 +833,13 @@ static inline void itimer_delete(struct k_itimer *timer)
{ {
unsigned long flags; unsigned long flags;
#ifdef CONFIG_SMP
int error;
retry_delete: retry_delete:
#endif
spin_lock_irqsave(&timer->it_lock, flags); spin_lock_irqsave(&timer->it_lock, flags);
#ifdef CONFIG_SMP if (timer_delete_hook(timer) == TIMER_RETRY) {
error = timer_delete_hook(timer);
if (error == TIMER_RETRY) {
unlock_timer(timer, flags); unlock_timer(timer, flags);
goto retry_delete; goto retry_delete;
} }
#else
timer_delete_hook(timer);
#endif
list_del(&timer->list); list_del(&timer->list);
/* /*
* This keeps any tasks waiting on the spin lock from thinking * This keeps any tasks waiting on the spin lock from thinking
@ -1164,57 +868,7 @@ void exit_itimers(struct signal_struct *sig)
} }
} }
/* /* Not available / possible... functions */
* 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);
}
int do_posix_clock_nosettime(const clockid_t clockid, struct timespec *tp) int do_posix_clock_nosettime(const clockid_t clockid, struct timespec *tp)
{ {
return -EINVAL; return -EINVAL;
@ -1287,107 +941,6 @@ sys_clock_getres(const clockid_t which_clock, struct timespec __user *tp)
return error; return error;
} }
/*
* 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 * nanosleep for monotonic and realtime clocks
*/ */
@ -1401,7 +954,7 @@ static int common_nsleep(const clockid_t which_clock, int flags,
case CLOCK_REALTIME: case CLOCK_REALTIME:
/* Posix madness. Only absolute timers on clock realtime /* Posix madness. Only absolute timers on clock realtime
are affected by clock set. */ are affected by clock set. */
if (mode == HRTIMER_ABS) if (mode != HRTIMER_ABS)
clockid = CLOCK_MONOTONIC; clockid = CLOCK_MONOTONIC;
case CLOCK_MONOTONIC: case CLOCK_MONOTONIC:
break; break;