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Message-Id: <11659069893843@2ka.mipt.ru> Date: Tue, 12 Dec 2006 10:03:09 +0300 From: Evgeniy Polyakov <johnpol@....mipt.ru> To: Evgeniy Polyakov <johnpol@....mipt.ru> Cc: David Miller <davem@...emloft.net>, Ulrich Drepper <drepper@...hat.com>, Andrew Morton <akpm@...l.org>, Evgeniy Polyakov <johnpol@....mipt.ru>, netdev <netdev@...r.kernel.org>, Zach Brown <zach.brown@...cle.com>, Christoph Hellwig <hch@...radead.org>, Chase Venters <chase.venters@...entec.com>, Johann Borck <johann.borck@...sedata.com>, linux-kernel@...r.kernel.org, Jeff Garzik <jeff@...zik.org> Subject: [take27 8/8] kevent: Kevent posix timer notifications. Kevent posix timer notifications. Simple extensions to POSIX timers which allows to deliver notification of the timer expiration through kevent queue. Example application posix_timer.c can be found in archive on project homepage. Signed-off-by: Evgeniy Polyakov <johnpol@....mipt.ru> diff --git a/include/asm-generic/siginfo.h b/include/asm-generic/siginfo.h index 8786e01..3768746 100644 --- a/include/asm-generic/siginfo.h +++ b/include/asm-generic/siginfo.h @@ -235,6 +235,7 @@ typedef struct siginfo { #define SIGEV_NONE 1 /* other notification: meaningless */ #define SIGEV_THREAD 2 /* deliver via thread creation */ #define SIGEV_THREAD_ID 4 /* deliver to thread */ +#define SIGEV_KEVENT 8 /* deliver through kevent queue */ /* * This works because the alignment is ok on all current architectures @@ -260,6 +261,8 @@ typedef struct sigevent { void (*_function)(sigval_t); void *_attribute; /* really pthread_attr_t */ } _sigev_thread; + + int kevent_fd; } _sigev_un; } sigevent_t; diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h index a7dd38f..4b9deb4 100644 --- a/include/linux/posix-timers.h +++ b/include/linux/posix-timers.h @@ -4,6 +4,7 @@ #include <linux/spinlock.h> #include <linux/list.h> #include <linux/sched.h> +#include <linux/kevent_storage.h> union cpu_time_count { cputime_t cpu; @@ -49,6 +50,9 @@ struct k_itimer { sigval_t it_sigev_value; /* value word of sigevent struct */ struct task_struct *it_process; /* process to send signal to */ struct sigqueue *sigq; /* signal queue entry. */ +#ifdef CONFIG_KEVENT_TIMER + struct kevent_storage st; +#endif union { struct { struct hrtimer timer; diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index e5ebcc1..8d0e7a3 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -48,6 +48,8 @@ #include <linux/wait.h> #include <linux/workqueue.h> #include <linux/module.h> +#include <linux/kevent.h> +#include <linux/file.h> /* * Management arrays for POSIX timers. Timers are kept in slab memory @@ -224,6 +226,99 @@ static int posix_ktime_get_ts(clockid_t which_clock, struct timespec *tp) return 0; } +#ifdef CONFIG_KEVENT_TIMER +static int posix_kevent_enqueue(struct kevent *k) +{ + /* + * It is not ugly - there is no pointer in the id field union, + * but its size is 64bits, which is ok for any known pointer size. + */ + struct k_itimer *tmr = (struct k_itimer *)(unsigned long)k->event.id.raw_u64; + return kevent_storage_enqueue(&tmr->st, k); +} +static int posix_kevent_dequeue(struct kevent *k) +{ + struct k_itimer *tmr = (struct k_itimer *)(unsigned long)k->event.id.raw_u64; + kevent_storage_dequeue(&tmr->st, k); + return 0; +} +static int posix_kevent_callback(struct kevent *k) +{ + return 1; +} +static int posix_kevent_init(void) +{ + struct kevent_callbacks tc = { + .callback = &posix_kevent_callback, + .enqueue = &posix_kevent_enqueue, + .dequeue = &posix_kevent_dequeue}; + + return kevent_add_callbacks(&tc, KEVENT_POSIX_TIMER); +} + +extern struct file_operations kevent_user_fops; + +static int posix_kevent_init_timer(struct k_itimer *tmr, int fd) +{ + struct ukevent uk; + struct file *file; + struct kevent_user *u; + int err; + + file = fget(fd); + if (!file) { + err = -EBADF; + goto err_out; + } + + if (file->f_op != &kevent_user_fops) { + err = -EINVAL; + goto err_out_fput; + } + + u = file->private_data; + + memset(&uk, 0, sizeof(struct ukevent)); + + uk.event = KEVENT_MASK_ALL; + uk.type = KEVENT_POSIX_TIMER; + uk.id.raw_u64 = (unsigned long)(tmr); /* Just cast to something unique */ + uk.req_flags = KEVENT_REQ_ONESHOT | KEVENT_REQ_ALWAYS_QUEUE; + uk.ptr = tmr->it_sigev_value.sival_ptr; + + err = kevent_user_add_ukevent(&uk, u); + if (err) + goto err_out_fput; + + fput(file); + + return 0; + +err_out_fput: + fput(file); +err_out: + return err; +} + +static void posix_kevent_fini_timer(struct k_itimer *tmr) +{ + kevent_storage_fini(&tmr->st); +} +#else +static int posix_kevent_init_timer(struct k_itimer *tmr, int fd) +{ + return -ENOSYS; +} +static int posix_kevent_init(void) +{ + return 0; +} +static void posix_kevent_fini_timer(struct k_itimer *tmr) +{ +} +#endif + + /* * Initialize everything, well, just everything in Posix clocks/timers ;) */ @@ -241,6 +336,11 @@ static __init int init_posix_timers(void) register_posix_clock(CLOCK_REALTIME, &clock_realtime); register_posix_clock(CLOCK_MONOTONIC, &clock_monotonic); + if (posix_kevent_init()) { + printk(KERN_ERR "Failed to initialize kevent posix timers.\n"); + BUG(); + } + posix_timers_cache = kmem_cache_create("posix_timers_cache", sizeof (struct k_itimer), 0, 0, NULL, NULL); idr_init(&posix_timers_id); @@ -343,23 +443,27 @@ static int posix_timer_fn(struct hrtimer *timer) timr = container_of(timer, struct k_itimer, it.real.timer); spin_lock_irqsave(&timr->it_lock, flags); + + if (timr->it_sigev_notify == SIGEV_KEVENT) { + kevent_storage_ready(&timr->st, NULL, KEVENT_MASK_ALL); + } else { + if (timr->it.real.interval.tv64 != 0) + si_private = ++timr->it_requeue_pending; - if (timr->it.real.interval.tv64 != 0) - si_private = ++timr->it_requeue_pending; - - 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(timer, - timer->base->softirq_time, - timr->it.real.interval); - ret = HRTIMER_RESTART; - ++timr->it_requeue_pending; + 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(timer, + timer->base->softirq_time, + timr->it.real.interval); + ret = HRTIMER_RESTART; + ++timr->it_requeue_pending; + } } } @@ -407,6 +511,9 @@ static struct k_itimer * alloc_posix_timer(void) kmem_cache_free(posix_timers_cache, tmr); tmr = NULL; } +#ifdef CONFIG_KEVENT_TIMER + kevent_storage_init(tmr, &tmr->st); +#endif return tmr; } @@ -424,6 +531,7 @@ static void release_posix_timer(struct k_itimer *tmr, int it_id_set) if (unlikely(tmr->it_process) && tmr->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) put_task_struct(tmr->it_process); + posix_kevent_fini_timer(tmr); kmem_cache_free(posix_timers_cache, tmr); } @@ -496,40 +604,52 @@ sys_timer_create(const clockid_t which_clock, new_timer->it_sigev_signo = event.sigev_signo; new_timer->it_sigev_value = event.sigev_value; - read_lock(&tasklist_lock); - if ((process = good_sigevent(&event))) { - /* - * We may be setting up this process for another - * thread. It may be exiting. To catch this - * case the we check the PF_EXITING flag. If - * the flag is not set, the siglock will catch - * him before it is too late (in exit_itimers). - * - * The exec case is a bit more invloved but easy - * to code. If the process is in our thread - * group (and it must be or we would not allow - * it here) and is doing an exec, it will cause - * us to be killed. In this case it will wait - * for us to die which means we can finish this - * linkage with our last gasp. I.e. no code :) - */ + if (event.sigev_notify == SIGEV_KEVENT) { + error = posix_kevent_init_timer(new_timer, event._sigev_un.kevent_fd); + if (error) + goto out; + + process = current->group_leader; spin_lock_irqsave(&process->sighand->siglock, flags); - if (!(process->flags & PF_EXITING)) { - 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); - } else { - spin_unlock_irqrestore(&process->sighand->siglock, flags); - process = NULL; + new_timer->it_process = process; + list_add(&new_timer->list, &process->signal->posix_timers); + spin_unlock_irqrestore(&process->sighand->siglock, flags); + } else { + read_lock(&tasklist_lock); + if ((process = good_sigevent(&event))) { + /* + * We may be setting up this process for another + * thread. It may be exiting. To catch this + * case the we check the PF_EXITING flag. If + * the flag is not set, the siglock will catch + * him before it is too late (in exit_itimers). + * + * The exec case is a bit more invloved but easy + * to code. If the process is in our thread + * group (and it must be or we would not allow + * it here) and is doing an exec, it will cause + * us to be killed. In this case it will wait + * for us to die which means we can finish this + * linkage with our last gasp. I.e. no code :) + */ + spin_lock_irqsave(&process->sighand->siglock, flags); + if (!(process->flags & PF_EXITING)) { + 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); + } else { + spin_unlock_irqrestore(&process->sighand->siglock, flags); + process = NULL; + } + } + read_unlock(&tasklist_lock); + if (!process) { + error = -EINVAL; + goto out; } - } - read_unlock(&tasklist_lock); - if (!process) { - error = -EINVAL; - goto out; } } else { new_timer->it_sigev_notify = SIGEV_SIGNAL; - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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