diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/exit.c | 2 | ||||
| -rw-r--r-- | kernel/fork.c | 6 | ||||
| -rw-r--r-- | kernel/itimer.c | 106 |
3 files changed, 55 insertions, 59 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 309a46fa16f..e75a51f3376 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -842,7 +842,7 @@ fastcall NORET_TYPE void do_exit(long code) } group_dead = atomic_dec_and_test(&tsk->signal->live); if (group_dead) { - del_timer_sync(&tsk->signal->real_timer); + hrtimer_cancel(&tsk->signal->real_timer); exit_itimers(tsk->signal); acct_process(code); } diff --git a/kernel/fork.c b/kernel/fork.c index b18d64554fe..3bdcab49998 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -801,10 +801,10 @@ static inline int copy_signal(unsigned long clone_flags, struct task_struct * ts init_sigpending(&sig->shared_pending); INIT_LIST_HEAD(&sig->posix_timers); - sig->it_real_value = sig->it_real_incr = 0; + hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC); + sig->it_real_incr.tv64 = 0; sig->real_timer.function = it_real_fn; - sig->real_timer.data = (unsigned long) tsk; - init_timer(&sig->real_timer); + sig->real_timer.data = tsk; sig->it_virt_expires = cputime_zero; sig->it_virt_incr = cputime_zero; diff --git a/kernel/itimer.c b/kernel/itimer.c index 7c1b25e25e4..c2c05c4ff28 100644 --- a/kernel/itimer.c +++ b/kernel/itimer.c @@ -12,36 +12,46 @@ #include <linux/syscalls.h> #include <linux/time.h> #include <linux/posix-timers.h> +#include <linux/hrtimer.h> #include <asm/uaccess.h> -static unsigned long it_real_value(struct signal_struct *sig) +/** + * itimer_get_remtime - get remaining time for the timer + * + * @timer: the timer to read + * + * Returns the delta between the expiry time and now, which can be + * less than zero or 1usec for an pending expired timer + */ +static struct timeval itimer_get_remtime(struct hrtimer *timer) { - unsigned long val = 0; - if (timer_pending(&sig->real_timer)) { - val = sig->real_timer.expires - jiffies; + ktime_t rem = hrtimer_get_remaining(timer); - /* look out for negative/zero itimer.. */ - if ((long) val <= 0) - val = 1; - } - return val; + /* + * Racy but safe: if the itimer expires after the above + * hrtimer_get_remtime() call but before this condition + * then we return 0 - which is correct. + */ + if (hrtimer_active(timer)) { + if (rem.tv64 <= 0) + rem.tv64 = NSEC_PER_USEC; + } else + rem.tv64 = 0; + + return ktime_to_timeval(rem); } int do_getitimer(int which, struct itimerval *value) { struct task_struct *tsk = current; - unsigned long interval, val; cputime_t cinterval, cval; switch (which) { case ITIMER_REAL: - spin_lock_irq(&tsk->sighand->siglock); - interval = tsk->signal->it_real_incr; - val = it_real_value(tsk->signal); - spin_unlock_irq(&tsk->sighand->siglock); - jiffies_to_timeval(val, &value->it_value); - jiffies_to_timeval(interval, &value->it_interval); + value->it_value = itimer_get_remtime(&tsk->signal->real_timer); + value->it_interval = + ktime_to_timeval(tsk->signal->it_real_incr); break; case ITIMER_VIRTUAL: read_lock(&tasklist_lock); @@ -113,59 +123,45 @@ asmlinkage long sys_getitimer(int which, struct itimerval __user *value) } -void it_real_fn(unsigned long __data) +/* + * The timer is automagically restarted, when interval != 0 + */ +int it_real_fn(void *data) { - struct task_struct * p = (struct task_struct *) __data; - unsigned long inc = p->signal->it_real_incr; + struct task_struct *tsk = (struct task_struct *) data; - send_group_sig_info(SIGALRM, SEND_SIG_PRIV, p); + send_group_sig_info(SIGALRM, SEND_SIG_PRIV, tsk); - /* - * Now restart the timer if necessary. We don't need any locking - * here because do_setitimer makes sure we have finished running - * before it touches anything. - * Note, we KNOW we are (or should be) at a jiffie edge here so - * we don't need the +1 stuff. Also, we want to use the prior - * expire value so as to not "slip" a jiffie if we are late. - * Deal with requesting a time prior to "now" here rather than - * in add_timer. - */ - if (!inc) - return; - while (time_before_eq(p->signal->real_timer.expires, jiffies)) - p->signal->real_timer.expires += inc; - add_timer(&p->signal->real_timer); + if (tsk->signal->it_real_incr.tv64 != 0) { + hrtimer_forward(&tsk->signal->real_timer, + tsk->signal->it_real_incr); + + return HRTIMER_RESTART; + } + return HRTIMER_NORESTART; } int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue) { struct task_struct *tsk = current; - unsigned long val, interval, expires; + struct hrtimer *timer; + ktime_t expires; cputime_t cval, cinterval, nval, ninterval; switch (which) { case ITIMER_REAL: -again: - spin_lock_irq(&tsk->sighand->siglock); - interval = tsk->signal->it_real_incr; - val = it_real_value(tsk->signal); - /* We are sharing ->siglock with it_real_fn() */ - if (try_to_del_timer_sync(&tsk->signal->real_timer) < 0) { - spin_unlock_irq(&tsk->sighand->siglock); - goto again; - } - tsk->signal->it_real_incr = - timeval_to_jiffies(&value->it_interval); - expires = timeval_to_jiffies(&value->it_value); - if (expires) - mod_timer(&tsk->signal->real_timer, - jiffies + 1 + expires); - spin_unlock_irq(&tsk->sighand->siglock); + timer = &tsk->signal->real_timer; + hrtimer_cancel(timer); if (ovalue) { - jiffies_to_timeval(val, &ovalue->it_value); - jiffies_to_timeval(interval, - &ovalue->it_interval); + ovalue->it_value = itimer_get_remtime(timer); + ovalue->it_interval + = ktime_to_timeval(tsk->signal->it_real_incr); } + tsk->signal->it_real_incr = + timeval_to_ktime(value->it_interval); + expires = timeval_to_ktime(value->it_value); + if (expires.tv64 != 0) + hrtimer_start(timer, expires, HRTIMER_REL); break; case ITIMER_VIRTUAL: nval = timeval_to_cputime(&value->it_value); |