X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Fposix-timers.c;h=e36d5798cbff427fca02fd8c9a8fb6f615dbd3fe;hb=b00c1a99e7758f794923c61e5cd55268d61c9469;hp=3b606d361b529dfda6097ba08e60bbdfd3be62aa;hpb=b6557fbca805217588a412f391a65ceafcf1a1af;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index 3b606d3..e36d579 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -1,5 +1,5 @@ /* - * linux/kernel/posix_timers.c + * linux/kernel/posix-timers.c * * * 2002-10-15 Posix Clocks & timers @@ -31,13 +31,12 @@ * POSIX clocks & timers */ #include -#include #include #include #include +#include #include -#include #include #include #include @@ -69,7 +68,7 @@ /* * Lets keep our timers in a slab cache :-) */ -static kmem_cache_t *posix_timers_cache; +static struct kmem_cache *posix_timers_cache; static struct idr posix_timers_id; static DEFINE_SPINLOCK(idr_lock); @@ -144,7 +143,7 @@ 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 enum hrtimer_restart posix_timer_fn(struct hrtimer *data); static struct k_itimer *lock_timer(timer_t timer_id, unsigned long *flags); @@ -194,9 +193,7 @@ static inline int common_clock_set(const clockid_t which_clock, static int common_timer_create(struct k_itimer *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; + hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0); return 0; } @@ -243,7 +240,8 @@ static __init int init_posix_timers(void) 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, SLAB_PANIC, + NULL); idr_init(&posix_timers_id); return 0; } @@ -252,15 +250,19 @@ __initcall(init_posix_timers); static void schedule_next_timer(struct k_itimer *timr) { + struct hrtimer *timer = &timr->it.real.timer; + if (timr->it.real.interval.tv64 == 0) return; - timr->it_overrun += hrtimer_forward(&timr->it.real.timer, - timr->it.real.interval); + timr->it_overrun += (unsigned int) hrtimer_forward(timer, + timer->base->get_time(), + timr->it.real.interval); + timr->it_overrun_last = timr->it_overrun; timr->it_overrun = -1; ++timr->it_requeue_pending; - hrtimer_restart(&timr->it.real.timer); + hrtimer_restart(timer); } /* @@ -287,29 +289,36 @@ void do_schedule_next_timer(struct siginfo *info) else schedule_next_timer(timr); - info->si_overrun = timr->it_overrun_last; + info->si_overrun += timr->it_overrun_last; } 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)); + /* + * FIXME: if ->sigq is queued we can race with + * dequeue_signal()->do_schedule_next_timer(). + * + * If dequeue_signal() sees the "right" value of + * si_sys_private it calls do_schedule_next_timer(). + * We re-queue ->sigq and drop ->it_lock(). + * do_schedule_next_timer() locks the timer + * and re-schedules it while ->sigq is pending. + * Not really bad, but not that we want. + */ timr->sigq->info.si_sys_private = si_private; - /* 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_tid = timr->it_id; timr->sigq->info.si_value = timr->it_sigev_value; if (timr->it_sigev_notify & SIGEV_THREAD_ID) { struct task_struct *leader; - int ret = send_sigqueue(timr->it_sigev_signo, timr->sigq, - timr->it_process); + int ret = send_sigqueue(timr->sigq, timr->it_process, 0); if (likely(ret >= 0)) return ret; @@ -320,8 +329,7 @@ int posix_timer_event(struct k_itimer *timr,int si_private) timr->it_process = leader; } - return send_group_sigqueue(timr->it_sigev_signo, timr->sigq, - timr->it_process); + return send_sigqueue(timr->sigq, timr->it_process, 1); } EXPORT_SYMBOL_GPL(posix_timer_event); @@ -332,13 +340,14 @@ EXPORT_SYMBOL_GPL(posix_timer_event); * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers. */ -static int posix_timer_fn(void *data) +static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer) { - struct k_itimer *timr = data; + struct k_itimer *timr; unsigned long flags; int si_private = 0; - int ret = HRTIMER_NORESTART; + enum hrtimer_restart ret = HRTIMER_NORESTART; + timr = container_of(timer, struct k_itimer, it.real.timer); spin_lock_irqsave(&timr->it_lock, flags); if (timr->it.real.interval.tv64 != 0) @@ -351,10 +360,43 @@ static int posix_timer_fn(void *data) * it should be restarted. */ if (timr->it.real.interval.tv64 != 0) { - timr->it_overrun += - hrtimer_forward(&timr->it.real.timer, + ktime_t now = hrtimer_cb_get_time(timer); + + /* + * FIXME: What we really want, is to stop this + * timer completely and restart it in case the + * SIG_IGN is removed. This is a non trivial + * change which involves sighand locking + * (sigh !), which we don't want to do late in + * the release cycle. + * + * For now we just let timers with an interval + * less than a jiffie expire every jiffie to + * avoid softirq starvation in case of SIG_IGN + * and a very small interval, which would put + * the timer right back on the softirq pending + * list. By moving now ahead of time we trick + * hrtimer_forward() to expire the timer + * later, while we still maintain the overrun + * accuracy, but have some inconsistency in + * the timer_gettime() case. This is at least + * better than a starved softirq. A more + * complex fix which solves also another related + * inconsistency is already in the pipeline. + */ +#ifdef CONFIG_HIGH_RES_TIMERS + { + ktime_t kj = ktime_set(0, NSEC_PER_SEC / HZ); + + if (timr->it.real.interval.tv64 < kj.tv64) + now = ktime_add(now, kj); + } +#endif + timr->it_overrun += (unsigned int) + hrtimer_forward(timer, now, timr->it.real.interval); ret = HRTIMER_RESTART; + ++timr->it_requeue_pending; } } @@ -367,8 +409,8 @@ static struct task_struct * good_sigevent(sigevent_t * event) struct task_struct *rtn = current->group_leader; if ((event->sigev_notify & SIGEV_THREAD_ID ) && - (!(rtn = find_task_by_pid(event->sigev_notify_thread_id)) || - rtn->tgid != current->tgid || + (!(rtn = find_task_by_vpid(event->sigev_notify_thread_id)) || + !same_thread_group(rtn, current) || (event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL)) return NULL; @@ -394,14 +436,14 @@ EXPORT_SYMBOL_GPL(register_posix_clock); static struct k_itimer * alloc_posix_timer(void) { struct k_itimer *tmr; - tmr = kmem_cache_alloc(posix_timers_cache, GFP_KERNEL); + tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL); if (!tmr) return tmr; - memset(tmr, 0, sizeof (struct k_itimer)); if (unlikely(!(tmr->sigq = sigqueue_alloc()))) { kmem_cache_free(posix_timers_cache, tmr); tmr = NULL; } + memset(&tmr->sigq->info, 0, sizeof(siginfo_t)); return tmr; } @@ -416,9 +458,6 @@ static void release_posix_timer(struct k_itimer *tmr, int it_id_set) spin_unlock_irqrestore(&idr_lock, flags); } sigqueue_free(tmr->sigq); - if (unlikely(tmr->it_process) && - tmr->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) - put_task_struct(tmr->it_process); kmem_cache_free(posix_timers_cache, tmr); } @@ -458,7 +497,7 @@ sys_timer_create(const clockid_t which_clock, goto retry; else if (error) { /* - * Wierd looking, but we return EAGAIN if the IDR is + * Weird looking, but we return EAGAIN if the IDR is * full (proper POSIX return value for this) */ error = -EAGAIN; @@ -513,9 +552,9 @@ sys_timer_create(const clockid_t which_clock, new_timer->it_process = process; list_add(&new_timer->list, &process->signal->posix_timers); - spin_unlock_irqrestore(&process->sighand->siglock, flags); if (new_timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) get_task_struct(process); + spin_unlock_irqrestore(&process->sighand->siglock, flags); } else { spin_unlock_irqrestore(&process->sighand->siglock, flags); process = NULL; @@ -571,13 +610,14 @@ static struct k_itimer * lock_timer(timer_t timer_id, unsigned long *flags) timr = (struct k_itimer *) idr_find(&posix_timers_id, (int) timer_id); if (timr) { spin_lock(&timr->it_lock); - spin_unlock(&idr_lock); if ((timr->it_id != timer_id) || !(timr->it_process) || - timr->it_process->tgid != current->tgid) { - unlock_timer(timr, *flags); + !same_thread_group(timr->it_process, current)) { + spin_unlock(&timr->it_lock); + spin_unlock_irqrestore(&idr_lock, *flags); timr = NULL; - } + } else + spin_unlock(&idr_lock); } else spin_unlock_irqrestore(&idr_lock, *flags); @@ -603,38 +643,41 @@ static struct k_itimer * lock_timer(timer_t timer_id, unsigned long *flags) static void common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting) { - ktime_t remaining; + ktime_t now, remaining, iv; struct hrtimer *timer = &timr->it.real.timer; memset(cur_setting, 0, sizeof(struct itimerspec)); - remaining = hrtimer_get_remaining(timer); - /* Time left ? or timer pending */ - if (remaining.tv64 > 0 || hrtimer_active(timer)) - goto calci; + iv = timr->it.real.interval; + /* interval timer ? */ - if (timr->it.real.interval.tv64 == 0) + if (iv.tv64) + cur_setting->it_interval = ktime_to_timespec(iv); + else if (!hrtimer_active(timer) && + (timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) return; + + now = timer->base->get_time(); + /* - * When a requeue is pending or this is a SIGEV_NONE timer - * move the expiry time forward by intervals, so expiry is > - * now. + * 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); + if (iv.tv64 && (timr->it_requeue_pending & REQUEUE_PENDING || + (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) + timr->it_overrun += (unsigned int) hrtimer_forward(timer, now, iv); + + remaining = ktime_sub(timer->expires, now); /* Return 0 only, when the timer is expired and not pending */ - if (remaining.tv64 <= 0) - cur_setting->it_value.tv_nsec = 1; - else + if (remaining.tv64 <= 0) { + /* + * A single shot SIGEV_NONE timer must return 0, when + * it is expired ! + */ + if ((timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) + cur_setting->it_value.tv_nsec = 1; + } else cur_setting->it_value = ktime_to_timespec(remaining); } @@ -674,7 +717,7 @@ sys_timer_getoverrun(timer_t timer_id) { struct k_itimer *timr; int overrun; - long flags; + unsigned long flags; timr = lock_timer(timer_id, &flags); if (!timr) @@ -693,6 +736,7 @@ common_timer_set(struct k_itimer *timr, int flags, struct itimerspec *new_setting, struct itimerspec *old_setting) { struct hrtimer *timer = &timr->it.real.timer; + enum hrtimer_mode mode; if (old_setting) common_timer_get(timr, old_setting); @@ -714,14 +758,9 @@ common_timer_set(struct k_itimer *timr, int flags, if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec) return 0; - /* Posix madness. Only absolute CLOCK_REALTIME timers - * are affected by clock sets. So we must reiniatilize - * the timer. - */ - if (timr->it_clock == CLOCK_REALTIME && (flags & TIMER_ABSTIME)) - hrtimer_rebase(timer, CLOCK_REALTIME); - else - hrtimer_rebase(timer, CLOCK_MONOTONIC); + mode = flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL; + hrtimer_init(&timr->it.real.timer, timr->it_clock, mode); + timr->it.real.timer.function = posix_timer_fn; timer->expires = timespec_to_ktime(new_setting->it_value); @@ -729,11 +768,17 @@ common_timer_set(struct k_itimer *timr, int flags, 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)) + if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) { + /* Setup correct expiry time for relative timers */ + if (mode == HRTIMER_MODE_REL) { + timer->expires = + ktime_add_safe(timer->expires, + timer->base->get_time()); + } return 0; + } - hrtimer_start(timer, timer->expires, (flags & TIMER_ABSTIME) ? - HRTIMER_ABS : HRTIMER_REL); + hrtimer_start(timer, timer->expires, mode); return 0; } @@ -746,7 +791,7 @@ sys_timer_settime(timer_t timer_id, int flags, struct k_itimer *timr; struct itimerspec new_spec, old_spec; int error = 0; - long flag; + unsigned long flag; struct itimerspec *rtn = old_setting ? &old_spec : NULL; if (!new_setting) @@ -798,7 +843,7 @@ asmlinkage long sys_timer_delete(timer_t timer_id) { struct k_itimer *timer; - long flags; + unsigned long flags; retry_delete: timer = lock_timer(timer_id, &flags); @@ -817,11 +862,10 @@ retry_delete: * This keeps any tasks waiting on the spin lock from thinking * they got something (see the lock code above). */ - if (timer->it_process) { - if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) - put_task_struct(timer->it_process); - timer->it_process = NULL; - } + if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) + put_task_struct(timer->it_process); + timer->it_process = NULL; + unlock_timer(timer, flags); release_posix_timer(timer, IT_ID_SET); return 0; @@ -846,11 +890,10 @@ retry_delete: * This keeps any tasks waiting on the spin lock from thinking * they got something (see the lock code above). */ - if (timer->it_process) { - if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) - put_task_struct(timer->it_process); - timer->it_process = NULL; - } + if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) + put_task_struct(timer->it_process); + timer->it_process = NULL; + unlock_timer(timer, flags); release_posix_timer(timer, IT_ID_SET); } @@ -876,12 +919,6 @@ int do_posix_clock_nosettime(const clockid_t clockid, struct timespec *tp) } EXPORT_SYMBOL_GPL(do_posix_clock_nosettime); -int do_posix_clock_notimer_create(struct k_itimer *timer) -{ - return -EINVAL; -} -EXPORT_SYMBOL_GPL(do_posix_clock_notimer_create); - int do_posix_clock_nonanosleep(const clockid_t clock, int flags, struct timespec *t, struct timespec __user *r) { @@ -948,21 +985,9 @@ sys_clock_getres(const clockid_t which_clock, struct timespec __user *tp) static int common_nsleep(const clockid_t which_clock, int flags, struct timespec *tsave, struct timespec __user *rmtp) { - int mode = flags & TIMER_ABSTIME ? HRTIMER_ABS : HRTIMER_REL; - int clockid = which_clock; - - switch (which_clock) { - case CLOCK_REALTIME: - /* Posix madness. Only absolute timers on clock realtime - are affected by clock set. */ - if (mode != HRTIMER_ABS) - clockid = CLOCK_MONOTONIC; - case CLOCK_MONOTONIC: - break; - default: - return -EINVAL; - } - return hrtimer_nanosleep(tsave, rmtp, mode, clockid); + return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ? + HRTIMER_MODE_ABS : HRTIMER_MODE_REL, + which_clock); } asmlinkage long @@ -984,3 +1009,24 @@ sys_clock_nanosleep(const clockid_t which_clock, int flags, return CLOCK_DISPATCH(which_clock, nsleep, (which_clock, flags, &t, rmtp)); } + +/* + * nanosleep_restart for monotonic and realtime clocks + */ +static int common_nsleep_restart(struct restart_block *restart_block) +{ + return hrtimer_nanosleep_restart(restart_block); +} + +/* + * This will restart clock_nanosleep. This is required only by + * compat_clock_nanosleep_restart for now. + */ +long +clock_nanosleep_restart(struct restart_block *restart_block) +{ + clockid_t which_clock = restart_block->arg0; + + return CLOCK_DISPATCH(which_clock, nsleep_restart, + (restart_block)); +}