X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=kernel%2Fitimer.c;h=379be2f8c84c33445b9cea549fe2c7215d3d6cc4;hb=64ba3f394c830ec48a1c31b53dcae312c56f1604;hp=1a95e09b41b62d1336e5d152a1bee33a032cd827;hpb=5273a3df6485dc2ad6aa7ddd441b9a21970f003b;p=linux-2.6.git diff --git a/kernel/itimer.c b/kernel/itimer.c index 1a95e09b4..379be2f8c 100644 --- a/kernel/itimer.c +++ b/kernel/itimer.c @@ -9,46 +9,107 @@ #include #include #include +#include #include +#include +#include #include +/** + * 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) +{ + ktime_t rem = hrtimer_get_remaining(timer); + + /* + * 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) { - register unsigned long val, interval; + struct task_struct *tsk = current; + cputime_t cinterval, cval; switch (which) { case ITIMER_REAL: - interval = current->it_real_incr; - val = 0; - /* - * FIXME! This needs to be atomic, in case the kernel timer happens! - */ - if (timer_pending(¤t->real_timer)) { - val = current->real_timer.expires - jiffies; - - /* look out for negative/zero itimer.. */ - if ((long) val <= 0) - val = 1; - } + spin_lock_irq(&tsk->sighand->siglock); + value->it_value = itimer_get_remtime(&tsk->signal->real_timer); + value->it_interval = + ktime_to_timeval(tsk->signal->it_real_incr); + spin_unlock_irq(&tsk->sighand->siglock); break; case ITIMER_VIRTUAL: - val = current->it_virt_value; - interval = current->it_virt_incr; + read_lock(&tasklist_lock); + spin_lock_irq(&tsk->sighand->siglock); + cval = tsk->signal->it_virt_expires; + cinterval = tsk->signal->it_virt_incr; + if (!cputime_eq(cval, cputime_zero)) { + struct task_struct *t = tsk; + cputime_t utime = tsk->signal->utime; + do { + utime = cputime_add(utime, t->utime); + t = next_thread(t); + } while (t != tsk); + if (cputime_le(cval, utime)) { /* about to fire */ + cval = jiffies_to_cputime(1); + } else { + cval = cputime_sub(cval, utime); + } + } + spin_unlock_irq(&tsk->sighand->siglock); + read_unlock(&tasklist_lock); + cputime_to_timeval(cval, &value->it_value); + cputime_to_timeval(cinterval, &value->it_interval); break; case ITIMER_PROF: - val = current->it_prof_value; - interval = current->it_prof_incr; + read_lock(&tasklist_lock); + spin_lock_irq(&tsk->sighand->siglock); + cval = tsk->signal->it_prof_expires; + cinterval = tsk->signal->it_prof_incr; + if (!cputime_eq(cval, cputime_zero)) { + struct task_struct *t = tsk; + cputime_t ptime = cputime_add(tsk->signal->utime, + tsk->signal->stime); + do { + ptime = cputime_add(ptime, + cputime_add(t->utime, + t->stime)); + t = next_thread(t); + } while (t != tsk); + if (cputime_le(cval, ptime)) { /* about to fire */ + cval = jiffies_to_cputime(1); + } else { + cval = cputime_sub(cval, ptime); + } + } + spin_unlock_irq(&tsk->sighand->siglock); + read_unlock(&tasklist_lock); + cputime_to_timeval(cval, &value->it_value); + cputime_to_timeval(cinterval, &value->it_interval); break; default: return(-EINVAL); } - jiffies_to_timeval(val, &value->it_value); - jiffies_to_timeval(interval, &value->it_interval); return 0; } -/* SMP: Only we modify our itimer values. */ asmlinkage long sys_getitimer(int which, struct itimerval __user *value) { int error = -EFAULT; @@ -63,64 +124,108 @@ asmlinkage long sys_getitimer(int which, struct itimerval __user *value) return error; } -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 interval; - - send_group_sig_info(SIGALRM, SEND_SIG_PRIV, p); - interval = p->it_real_incr; - if (interval) { - if (interval > (unsigned long) LONG_MAX) - interval = LONG_MAX; - p->real_timer.expires = jiffies + interval; - add_timer(&p->real_timer); + struct task_struct *tsk = (struct task_struct *) data; + + send_group_sig_info(SIGALRM, SEND_SIG_PRIV, tsk); + + 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) { - register unsigned long i, j; - int k; + struct task_struct *tsk = current; + struct hrtimer *timer; + ktime_t expires; + cputime_t cval, cinterval, nval, ninterval; - i = timeval_to_jiffies(&value->it_interval); - j = timeval_to_jiffies(&value->it_value); - if (ovalue && (k = do_getitimer(which, ovalue)) < 0) - return k; switch (which) { - case ITIMER_REAL: - del_timer_sync(¤t->real_timer); - current->it_real_value = j; - current->it_real_incr = i; - if (!j) - break; - if (j > (unsigned long) LONG_MAX) - j = LONG_MAX; - i = j + jiffies; - current->real_timer.expires = i; - add_timer(¤t->real_timer); - break; - case ITIMER_VIRTUAL: - if (j) - j++; - current->it_virt_value = j; - current->it_virt_incr = i; - break; - case ITIMER_PROF: - if (j) - j++; - current->it_prof_value = j; - current->it_prof_incr = i; - break; - default: - return -EINVAL; + case ITIMER_REAL: +again: + spin_lock_irq(&tsk->sighand->siglock); + timer = &tsk->signal->real_timer; + if (ovalue) { + ovalue->it_value = itimer_get_remtime(timer); + ovalue->it_interval + = ktime_to_timeval(tsk->signal->it_real_incr); + } + /* We are sharing ->siglock with it_real_fn() */ + if (hrtimer_try_to_cancel(timer) < 0) { + spin_unlock_irq(&tsk->sighand->siglock); + goto again; + } + 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); + spin_unlock_irq(&tsk->sighand->siglock); + break; + case ITIMER_VIRTUAL: + nval = timeval_to_cputime(&value->it_value); + ninterval = timeval_to_cputime(&value->it_interval); + read_lock(&tasklist_lock); + spin_lock_irq(&tsk->sighand->siglock); + cval = tsk->signal->it_virt_expires; + cinterval = tsk->signal->it_virt_incr; + if (!cputime_eq(cval, cputime_zero) || + !cputime_eq(nval, cputime_zero)) { + if (cputime_gt(nval, cputime_zero)) + nval = cputime_add(nval, + jiffies_to_cputime(1)); + set_process_cpu_timer(tsk, CPUCLOCK_VIRT, + &nval, &cval); + } + tsk->signal->it_virt_expires = nval; + tsk->signal->it_virt_incr = ninterval; + spin_unlock_irq(&tsk->sighand->siglock); + read_unlock(&tasklist_lock); + if (ovalue) { + cputime_to_timeval(cval, &ovalue->it_value); + cputime_to_timeval(cinterval, &ovalue->it_interval); + } + break; + case ITIMER_PROF: + nval = timeval_to_cputime(&value->it_value); + ninterval = timeval_to_cputime(&value->it_interval); + read_lock(&tasklist_lock); + spin_lock_irq(&tsk->sighand->siglock); + cval = tsk->signal->it_prof_expires; + cinterval = tsk->signal->it_prof_incr; + if (!cputime_eq(cval, cputime_zero) || + !cputime_eq(nval, cputime_zero)) { + if (cputime_gt(nval, cputime_zero)) + nval = cputime_add(nval, + jiffies_to_cputime(1)); + set_process_cpu_timer(tsk, CPUCLOCK_PROF, + &nval, &cval); + } + tsk->signal->it_prof_expires = nval; + tsk->signal->it_prof_incr = ninterval; + spin_unlock_irq(&tsk->sighand->siglock); + read_unlock(&tasklist_lock); + if (ovalue) { + cputime_to_timeval(cval, &ovalue->it_value); + cputime_to_timeval(cinterval, &ovalue->it_interval); + } + break; + default: + return -EINVAL; } return 0; } -/* SMP: Again, only we play with our itimers, and signals are SMP safe - * now so that is not an issue at all anymore. - */ asmlinkage long sys_setitimer(int which, struct itimerval __user *value, struct itimerval __user *ovalue) @@ -134,7 +239,7 @@ asmlinkage long sys_setitimer(int which, } else memset((char *) &set_buffer, 0, sizeof(set_buffer)); - error = do_setitimer(which, &set_buffer, ovalue ? &get_buffer : 0); + error = do_setitimer(which, &set_buffer, ovalue ? &get_buffer : NULL); if (error || !ovalue) return error;