X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Fposix-timers.c;h=35b4bbfc78ff6ee7d3f389baf0430231ed09af7b;hb=77034937dc4575ca0a76bf209838ecd39e804089;hp=a1bf616178394f1906a11bb2bb063d16cb3b5902;hpb=a727fea99bf4b2addcd64c596735148117a7b37f;p=linux-2.6 diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index a1bf616178..35b4bbfc78 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -31,7 +31,6 @@ * POSIX clocks & timers */ #include -#include #include #include #include @@ -145,7 +144,7 @@ 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(struct hrtimer *data); +static enum hrtimer_restart posix_timer_fn(struct hrtimer *data); static struct k_itimer *lock_timer(timer_t timer_id, unsigned long *flags); @@ -242,7 +241,8 @@ 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; } @@ -334,12 +334,12 @@ EXPORT_SYMBOL_GPL(posix_timer_event); * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers. */ -static int posix_timer_fn(struct hrtimer *timer) +static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer) { 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); @@ -354,9 +354,40 @@ static int posix_timer_fn(struct hrtimer *timer) * it should be restarted. */ if (timr->it.real.interval.tv64 != 0) { + 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 += - hrtimer_forward(timer, - timer->base->softirq_time, + hrtimer_forward(timer, now, timr->it.real.interval); ret = HRTIMER_RESTART; ++timr->it_requeue_pending; @@ -373,7 +404,7 @@ static struct task_struct * good_sigevent(sigevent_t * event) if ((event->sigev_notify & SIGEV_THREAD_ID ) && (!(rtn = find_task_by_pid(event->sigev_notify_thread_id)) || - rtn->tgid != current->tgid || + !same_thread_group(rtn, current) || (event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL)) return NULL; @@ -517,9 +548,9 @@ 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; @@ -575,13 +606,14 @@ 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); @@ -681,7 +713,7 @@ 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) @@ -722,7 +754,7 @@ common_timer_set(struct k_itimer *timr, int flags, if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec) return 0; - mode = flags & TIMER_ABSTIME ? HRTIMER_ABS : HRTIMER_REL; + 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; @@ -734,7 +766,7 @@ common_timer_set(struct k_itimer *timr, int flags, /* SIGEV_NONE timers are not queued ! See common_timer_get */ if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) { /* Setup correct expiry time for relative timers */ - if (mode == HRTIMER_REL) + if (mode == HRTIMER_MODE_REL) timer->expires = ktime_add(timer->expires, timer->base->get_time()); return 0; @@ -753,7 +785,7 @@ 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) @@ -805,7 +837,7 @@ 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); @@ -949,8 +981,20 @@ 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) { - return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ? - HRTIMER_ABS : HRTIMER_REL, which_clock); + struct timespec rmt; + int ret; + + ret = hrtimer_nanosleep(tsave, rmtp ? &rmt : NULL, + flags & TIMER_ABSTIME ? + HRTIMER_MODE_ABS : HRTIMER_MODE_REL, + which_clock); + + if (ret && rmtp) { + if (copy_to_user(rmtp, &rmt, sizeof(*rmtp))) + return -EFAULT; + } + + return ret; } asmlinkage long