* Update expiry time from increment, and increase overrun count,
* given the current clock sample.
*/
-static inline void bump_cpu_timer(struct k_itimer *timer,
+static void bump_cpu_timer(struct k_itimer *timer,
union cpu_time_count now)
{
int i;
for (i = 0; incr < delta - incr; i++)
incr = incr << 1;
for (; i >= 0; incr >>= 1, i--) {
- if (delta <= incr)
+ if (delta < incr)
continue;
timer->it.cpu.expires.sched += incr;
timer->it_overrun += 1 << i;
for (i = 0; cputime_lt(incr, cputime_sub(delta, incr)); i++)
incr = cputime_add(incr, incr);
for (; i >= 0; incr = cputime_halve(incr), i--) {
- if (cputime_le(delta, incr))
+ if (cputime_lt(delta, incr))
continue;
timer->it.cpu.expires.cpu =
cputime_add(timer->it.cpu.expires.cpu, incr);
int posix_cpu_timer_del(struct k_itimer *timer)
{
struct task_struct *p = timer->it.cpu.task;
+ int ret = 0;
- if (timer->it.cpu.firing)
- return TIMER_RETRY;
-
- if (unlikely(p == NULL))
- return 0;
+ if (likely(p != NULL)) {
+ read_lock(&tasklist_lock);
+ if (unlikely(p->signal == NULL)) {
+ /*
+ * We raced with the reaping of the task.
+ * The deletion should have cleared us off the list.
+ */
+ BUG_ON(!list_empty(&timer->it.cpu.entry));
+ } else {
+ spin_lock(&p->sighand->siglock);
+ if (timer->it.cpu.firing)
+ ret = TIMER_RETRY;
+ else
+ list_del(&timer->it.cpu.entry);
+ spin_unlock(&p->sighand->siglock);
+ }
+ read_unlock(&tasklist_lock);
- spin_lock(&p->sighand->siglock);
- if (!list_empty(&timer->it.cpu.entry)) {
- /*
- * Take us off the task's timer list. We don't need to
- * take tasklist_lock and check for the task being reaped.
- * If it was reaped, it already called posix_cpu_timers_exit
- * and posix_cpu_timers_exit_group to clear all the timers
- * that pointed to it.
- */
- list_del(&timer->it.cpu.entry);
- put_task_struct(p);
+ if (!ret)
+ put_task_struct(p);
}
- spin_unlock(&p->sighand->siglock);
- return 0;
+ return ret;
}
/*
cputime_t ptime = cputime_add(utime, stime);
list_for_each_entry_safe(timer, next, head, entry) {
- put_task_struct(timer->task);
- timer->task = NULL;
list_del_init(&timer->entry);
if (cputime_lt(timer->expires.cpu, ptime)) {
timer->expires.cpu = cputime_zero;
++head;
list_for_each_entry_safe(timer, next, head, entry) {
- put_task_struct(timer->task);
- timer->task = NULL;
list_del_init(&timer->entry);
if (cputime_lt(timer->expires.cpu, utime)) {
timer->expires.cpu = cputime_zero;
++head;
list_for_each_entry_safe(timer, next, head, entry) {
- put_task_struct(timer->task);
- timer->task = NULL;
list_del_init(&timer->entry);
if (timer->expires.sched < sched_time) {
timer->expires.sched = 0;
struct task_struct *t = p;
unsigned int nthreads = atomic_read(&p->signal->live);
+ if (!nthreads)
+ return;
+
switch (clock_idx) {
default:
BUG();
left = cputime_div(cputime_sub(expires.cpu, val.cpu),
nthreads);
do {
- if (!unlikely(t->exit_state)) {
+ if (likely(!(t->flags & PF_EXITING))) {
ticks = cputime_add(prof_ticks(t), left);
if (cputime_eq(t->it_prof_expires,
cputime_zero) ||
left = cputime_div(cputime_sub(expires.cpu, val.cpu),
nthreads);
do {
- if (!unlikely(t->exit_state)) {
+ if (likely(!(t->flags & PF_EXITING))) {
ticks = cputime_add(virt_ticks(t), left);
if (cputime_eq(t->it_virt_expires,
cputime_zero) ||
nsleft = expires.sched - val.sched;
do_div(nsleft, nthreads);
do {
- if (!unlikely(t->exit_state)) {
+ if (likely(!(t->flags & PF_EXITING))) {
ns = t->sched_time + nsleft;
if (t->it_sched_expires == 0 ||
t->it_sched_expires > ns) {
struct cpu_timer_list *next;
unsigned long i;
+ if (CPUCLOCK_PERTHREAD(timer->it_clock) && (p->flags & PF_EXITING))
+ return;
+
head = (CPUCLOCK_PERTHREAD(timer->it_clock) ?
p->cpu_timers : p->signal->cpu_timers);
head += CPUCLOCK_WHICH(timer->it_clock);
listpos = head;
if (CPUCLOCK_WHICH(timer->it_clock) == CPUCLOCK_SCHED) {
list_for_each_entry(next, head, entry) {
- if (next->expires.sched > nt->expires.sched) {
- listpos = &next->entry;
+ if (next->expires.sched > nt->expires.sched)
break;
- }
+ listpos = &next->entry;
}
} else {
list_for_each_entry(next, head, entry) {
- if (cputime_gt(next->expires.cpu, nt->expires.cpu)) {
- listpos = &next->entry;
+ if (cputime_gt(next->expires.cpu, nt->expires.cpu))
break;
- }
+ listpos = &next->entry;
}
}
list_add(&nt->entry, listpos);
* Disarm any old timer after extracting its expiry time.
*/
BUG_ON(!irqs_disabled());
+
+ ret = 0;
spin_lock(&p->sighand->siglock);
old_expires = timer->it.cpu.expires;
- list_del_init(&timer->it.cpu.entry);
+ if (unlikely(timer->it.cpu.firing)) {
+ timer->it.cpu.firing = -1;
+ ret = TIMER_RETRY;
+ } else
+ list_del_init(&timer->it.cpu.entry);
spin_unlock(&p->sighand->siglock);
/*
}
}
- if (unlikely(timer->it.cpu.firing)) {
+ if (unlikely(ret)) {
/*
* We are colliding with the timer actually firing.
* Punt after filling in the timer's old value, and
* it as an overrun (thanks to bump_cpu_timer above).
*/
read_unlock(&tasklist_lock);
- timer->it.cpu.firing = -1;
- ret = TIMER_RETRY;
goto out;
}
static void check_thread_timers(struct task_struct *tsk,
struct list_head *firing)
{
+ int maxfire;
struct list_head *timers = tsk->cpu_timers;
+ maxfire = 20;
tsk->it_prof_expires = cputime_zero;
while (!list_empty(timers)) {
struct cpu_timer_list *t = list_entry(timers->next,
struct cpu_timer_list,
entry);
- if (cputime_lt(prof_ticks(tsk), t->expires.cpu)) {
+ if (!--maxfire || cputime_lt(prof_ticks(tsk), t->expires.cpu)) {
tsk->it_prof_expires = t->expires.cpu;
break;
}
}
++timers;
+ maxfire = 20;
tsk->it_virt_expires = cputime_zero;
while (!list_empty(timers)) {
struct cpu_timer_list *t = list_entry(timers->next,
struct cpu_timer_list,
entry);
- if (cputime_lt(virt_ticks(tsk), t->expires.cpu)) {
+ if (!--maxfire || cputime_lt(virt_ticks(tsk), t->expires.cpu)) {
tsk->it_virt_expires = t->expires.cpu;
break;
}
}
++timers;
+ maxfire = 20;
tsk->it_sched_expires = 0;
while (!list_empty(timers)) {
struct cpu_timer_list *t = list_entry(timers->next,
struct cpu_timer_list,
entry);
- if (tsk->sched_time < t->expires.sched) {
+ if (!--maxfire || tsk->sched_time < t->expires.sched) {
tsk->it_sched_expires = t->expires.sched;
break;
}
static void check_process_timers(struct task_struct *tsk,
struct list_head *firing)
{
+ int maxfire;
struct signal_struct *const sig = tsk->signal;
cputime_t utime, stime, ptime, virt_expires, prof_expires;
unsigned long long sched_time, sched_expires;
} while (t != tsk);
ptime = cputime_add(utime, stime);
+ maxfire = 20;
prof_expires = cputime_zero;
while (!list_empty(timers)) {
struct cpu_timer_list *t = list_entry(timers->next,
struct cpu_timer_list,
entry);
- if (cputime_lt(ptime, t->expires.cpu)) {
+ if (!--maxfire || cputime_lt(ptime, t->expires.cpu)) {
prof_expires = t->expires.cpu;
break;
}
}
++timers;
+ maxfire = 20;
virt_expires = cputime_zero;
while (!list_empty(timers)) {
struct cpu_timer_list *t = list_entry(timers->next,
struct cpu_timer_list,
entry);
- if (cputime_lt(utime, t->expires.cpu)) {
+ if (!--maxfire || cputime_lt(utime, t->expires.cpu)) {
virt_expires = t->expires.cpu;
break;
}
}
++timers;
+ maxfire = 20;
sched_expires = 0;
while (!list_empty(timers)) {
struct cpu_timer_list *t = list_entry(timers->next,
struct cpu_timer_list,
entry);
- if (sched_time < t->expires.sched) {
+ if (!--maxfire || sched_time < t->expires.sched) {
sched_expires = t->expires.sched;
break;
}
unsigned long long sched_left, sched;
const unsigned int nthreads = atomic_read(&sig->live);
+ if (!nthreads)
+ return;
+
prof_left = cputime_sub(prof_expires, utime);
prof_left = cputime_sub(prof_left, stime);
prof_left = cputime_div(prof_left, nthreads);
do {
t = next_thread(t);
- } while (unlikely(t->exit_state));
+ } while (unlikely(t->flags & PF_EXITING));
} while (t != tsk);
}
}
/*
* The task was cleaned up already, no future firings.
*/
- return;
+ goto out;
/*
* Fetch the current sample and update the timer's expiry time.
bump_cpu_timer(timer, now);
if (unlikely(p->exit_state)) {
clear_dead_task(timer, now);
- return;
+ goto out;
}
read_lock(&tasklist_lock); /* arm_timer needs it. */
} else {
put_task_struct(p);
timer->it.cpu.task = p = NULL;
timer->it.cpu.expires.sched = 0;
- read_unlock(&tasklist_lock);
- return;
+ goto out_unlock;
} else if (unlikely(p->exit_state) && thread_group_empty(p)) {
/*
* We've noticed that the thread is dead, but
* drop our task ref.
*/
clear_dead_task(timer, now);
- read_unlock(&tasklist_lock);
- return;
+ goto out_unlock;
}
cpu_clock_sample_group(timer->it_clock, p, &now);
bump_cpu_timer(timer, now);
*/
arm_timer(timer, now);
+out_unlock:
read_unlock(&tasklist_lock);
+
+out:
+ timer->it_overrun_last = timer->it_overrun;
+ timer->it_overrun = -1;
+ ++timer->it_requeue_pending;
}
/*
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff