*
* Copyright (C) 2002 2003 by MontaVista Software.
*
- * 2004-06-01 Fix CLOCK_REALTIME clock/timer TIMER_ABSTIME bug.
- * Copyright (C) 2004 Boris Hu
- *
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
#include <linux/idr.h>
#include <linux/posix-timers.h>
#include <linux/wait.h>
-#include <linux/workqueue.h>
#ifndef div_long_long_rem
#include <asm/div64.h>
*/
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};
#define if_clock_do(clock_fun,alt_fun,parms) \
(!clock_fun) ? alt_fun parms : clock_fun parms
*/
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 = {.res = CLOCK_REALTIME_RES };
struct k_clock clock_monotonic = {.res = CLOCK_REALTIME_RES,
- .abs_struct = NULL,
.clock_get = do_posix_clock_monotonic_gettime,
.clock_set = do_posix_clock_monotonic_settime
};
register_posix_clock(CLOCK_MONOTONIC, &clock_monotonic);
posix_timers_cache = kmem_cache_create("posix_timers_cache",
- sizeof (struct k_itimer), 0, 0, NULL, NULL);
+ sizeof (struct k_itimer), 0, 0, 0, 0);
idr_init(&posix_timers_id);
+
return 0;
}
(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->wall_to_prev.tv_sec,
- new_wall_to->tv_nsec -
- timr->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->wall_to_prev = *new_wall_to;
- timr->it_timer.expires += (sign ? -exp : exp);
- return 1;
-}
-
-static void remove_from_abslist(struct k_itimer *timr)
-{
- if (!list_empty(&timr->abs_timer_entry)) {
- spin_lock(&abs_list.lock);
- list_del_init(&timr->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
- * 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).
- */
+ /* Set up the timer for the next interval (if there is one) */
if (!timr->it_incr)
return;
+ posix_get_now(&now);
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->abs_timer_entry)) {
- spin_lock(&abs_list.lock);
- add_clockset_delta(timr, &new_wall_to);
-
- posix_bump_timer(timr, now);
+ posix_bump_timer(timr);
+ }while (posix_time_before(&timr->it_timer, &now));
- spin_unlock(&abs_list.lock);
- } else {
- posix_bump_timer(timr, now);
- }
timr->it_overrun_last = timr->it_overrun;
timr->it_overrun = -1;
++timr->it_requeue_pending;
memset(&timr->sigq->info, 0, sizeof(siginfo_t));
- /*
- * 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;
timr->sigq->info.si_code = SI_TIMER;
timr->sigq->info.si_value = timr->it_sigev_value;
if (timr->it_incr)
timr->sigq->info.si_sys_private = ++timr->it_requeue_pending;
- else {
- remove_from_abslist(timr);
- }
if (timr->it_sigev_notify & SIGEV_THREAD_ID) {
if (unlikely(timr->it_process->flags & PF_EXITING)) {
* This function gets called when a POSIX.1b interval timer expires. It
* is used as a callback from the kernel internal timer. The
* run_timer_list code ALWAYS calls with interrutps on.
-
- * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers.
*/
static void posix_timer_fn(unsigned long __data)
{
struct k_itimer *timr = (struct k_itimer *) __data;
unsigned long flags;
- unsigned long seq;
- struct timespec delta, new_wall_to;
- u64 exp = 0;
- int do_notify = 1;
spin_lock_irqsave(&timr->it_lock, flags);
set_timer_inactive(timr);
- if (!list_empty(&timr->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->wall_to_prev.tv_sec,
- new_wall_to.tv_nsec -
- timr->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->wall_to_prev = new_wall_to;
- timr->it_timer.expires += exp;
- add_timer(&timr->it_timer);
- do_notify = 0;
- }
- spin_unlock(&abs_list.lock);
-
- }
- if (do_notify)
- timer_notify_task(timr);
- unlock_timer(timr, flags); /* hold thru abs lock to keep irq off */
+ timer_notify_task(timr);
+ unlock_timer(timr, flags);
}
if (!tmr)
return tmr;
memset(tmr, 0, sizeof (struct k_itimer));
- INIT_LIST_HEAD(&tmr->abs_timer_entry);
if (unlikely(!(tmr->sigq = sigqueue_alloc()))) {
kmem_cache_free(posix_timers_cache, tmr);
- tmr = NULL;
+ tmr = 0;
}
return tmr;
}
int error = 0;
struct k_itimer *new_timer = NULL;
int new_timer_id;
- struct task_struct *process = NULL;
+ struct task_struct *process = 0;
unsigned long flags;
sigevent_t event;
int it_id_set = IT_ID_NOT_SET;
get_task_struct(process);
} else {
spin_unlock_irqrestore(&process->sighand->siglock, flags);
- process = NULL;
+ process = 0;
}
}
read_unlock(&tasklist_lock);
if (expires) {
if (timr->it_requeue_pending & REQUEUE_PENDING ||
(timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) {
- posix_bump_timer(timr, now);
+ while (posix_time_before(&timr->it_timer, &now))
+ posix_bump_timer(timr);
expires = timr->it_timer.expires;
}
else
* 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)
+ int abs, u64 *exp)
{
struct timespec now;
struct timespec oc = *tp;
+ struct timespec wall_to_mono;
u64 jiffies_64_f;
int rtn =0;
/*
* The mask pick up the 4 basic clocks
*/
- if (!((clock - &posix_clocks[0]) & ~CLOCKS_MASK)) {
+ if (!(clock - &posix_clocks[0]) & ~CLOCKS_MASK) {
jiffies_64_f = do_posix_clock_monotonic_gettime_parts(
- &now, wall_to);
+ &now, &wall_to_mono);
/*
* 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;
+ now.tv_sec += wall_to_mono.tv_sec;
+ now.tv_nsec += wall_to_mono.tv_nsec;
}
} else {
/*
#else
del_timer(&timr->it_timer);
#endif
- remove_from_abslist(timr);
-
timr->it_requeue_pending = (timr->it_requeue_pending + 2) &
~REQUEUE_PENDING;
timr->it_overrun_last = 0;
if (adjust_abs_time(clock,
&new_setting->it_value, flags & TIMER_ABSTIME,
- &expire_64, &(timr->wall_to_prev))) {
+ &expire_64)) {
return -EINVAL;
}
timr->it_timer.expires = (unsigned long)expire_64;
tstojiffie(&new_setting->it_interval, clock->res, &expire_64);
timr->it_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.
+ * For some reason the timer does not fire immediately if expires is
+ * equal to jiffies, so the timer notify function is called directly.
+ * We do not even queue SIGEV_NONE timers!
*/
- if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE))
- add_timer(&timr->it_timer);
-
- if (flags & TIMER_ABSTIME && clock->abs_struct) {
- spin_lock(&clock->abs_struct->lock);
- list_add_tail(&(timr->abs_timer_entry),
- &(clock->abs_struct->list));
- spin_unlock(&clock->abs_struct->lock);
+ if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)) {
+ if (timr->it_timer.expires == jiffies)
+ timer_notify_task(timr);
+ else
+ add_timer(&timr->it_timer);
}
return 0;
}
if (!posix_clocks[timr->it_clock].timer_set)
error = do_timer_settime(timr, flags, &new_spec, rtn);
else
- error = posix_clocks[timr->it_clock].timer_set(timr,
+ error = posix_clocks[timr->it_clock].timer_set(timr,
flags,
&new_spec, rtn);
unlock_timer(timr, flag);
#else
del_timer(&timer->it_timer);
#endif
- remove_from_abslist(timer);
-
return 0;
}
* 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,
- abs_timer_entry);
-
- list_del_init(&timr->abs_timer_entry);
- if (add_clockset_delta(timr, &new_wall_to) &&
- del_timer(&timr->it_timer)) /* timer run yet? */
- add_timer(&timr->it_timer);
- list_add(&timr->abs_timer_entry, &abs_list.list);
- spin_unlock_irq(&abs_list.lock);
- } while (1);
-
- up(&clock_was_set_lock);
}
long clock_nanosleep_restart(struct restart_block *restart_block);
long
do_clock_nanosleep(clockid_t which_clock, int flags, struct timespec *tsave)
{
- struct timespec t, dum;
+ struct timespec t;
struct timer_list new_timer;
DECLARE_WAITQUEUE(abs_wqueue, current);
u64 rq_time = (u64)0;
t = *tsave;
if (abs || !rq_time) {
adjust_abs_time(&posix_clocks[which_clock], &t, abs,
- &rq_time, &dum);
+ &rq_time);
rq_time += (t.tv_sec || t.tv_nsec);
}
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