aboutsummaryrefslogtreecommitdiff
path: root/kernel/posix-cpu-timers.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/posix-cpu-timers.c')
-rw-r--r--kernel/posix-cpu-timers.c94
1 files changed, 52 insertions, 42 deletions
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 7a51a5597c3..bf374fceb39 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -91,7 +91,7 @@ static inline union cpu_time_count cpu_time_sub(clockid_t which_clock,
* 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;
@@ -110,7 +110,7 @@ static inline void bump_cpu_timer(struct k_itimer *timer,
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;
@@ -128,7 +128,7 @@ static inline void bump_cpu_timer(struct k_itimer *timer,
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);
@@ -380,14 +380,9 @@ int posix_cpu_timer_create(struct k_itimer *new_timer)
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 (!list_empty(&timer->it.cpu.entry)) {
+ if (likely(p != NULL)) {
read_lock(&tasklist_lock);
if (unlikely(p->signal == NULL)) {
/*
@@ -396,18 +391,20 @@ int posix_cpu_timer_del(struct k_itimer *timer)
*/
BUG_ON(!list_empty(&timer->it.cpu.entry));
} else {
- /*
- * Take us off the task's timer list.
- */
spin_lock(&p->sighand->siglock);
- list_del(&timer->it.cpu.entry);
+ if (timer->it.cpu.firing)
+ ret = TIMER_RETRY;
+ else
+ list_del(&timer->it.cpu.entry);
spin_unlock(&p->sighand->siglock);
}
read_unlock(&tasklist_lock);
+
+ if (!ret)
+ put_task_struct(p);
}
- put_task_struct(p);
- return 0;
+ return ret;
}
/*
@@ -424,8 +421,6 @@ static void cleanup_timers(struct list_head *head,
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;
@@ -437,8 +432,6 @@ static void cleanup_timers(struct list_head *head,
++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;
@@ -450,8 +443,6 @@ static void cleanup_timers(struct list_head *head,
++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;
@@ -495,6 +486,9 @@ static void process_timer_rebalance(struct task_struct *p,
struct task_struct *t = p;
unsigned int nthreads = atomic_read(&p->signal->live);
+ if (!nthreads)
+ return;
+
switch (clock_idx) {
default:
BUG();
@@ -503,7 +497,7 @@ static void process_timer_rebalance(struct task_struct *p,
left = cputime_div(cputime_sub(expires.cpu, val.cpu),
nthreads);
do {
- if (!unlikely(t->exit_state)) {
+ if (!unlikely(t->flags & PF_EXITING)) {
ticks = cputime_add(prof_ticks(t), left);
if (cputime_eq(t->it_prof_expires,
cputime_zero) ||
@@ -518,7 +512,7 @@ static void process_timer_rebalance(struct task_struct *p,
left = cputime_div(cputime_sub(expires.cpu, val.cpu),
nthreads);
do {
- if (!unlikely(t->exit_state)) {
+ if (!unlikely(t->flags & PF_EXITING)) {
ticks = cputime_add(virt_ticks(t), left);
if (cputime_eq(t->it_virt_expires,
cputime_zero) ||
@@ -533,7 +527,7 @@ static void process_timer_rebalance(struct task_struct *p,
nsleft = expires.sched - val.sched;
do_div(nsleft, nthreads);
do {
- if (!unlikely(t->exit_state)) {
+ if (!unlikely(t->flags & PF_EXITING)) {
ns = t->sched_time + nsleft;
if (t->it_sched_expires == 0 ||
t->it_sched_expires > ns) {
@@ -572,6 +566,9 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
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);
@@ -582,17 +579,15 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
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);
@@ -736,9 +731,15 @@ int posix_cpu_timer_set(struct k_itimer *timer, int flags,
* 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);
/*
@@ -786,7 +787,7 @@ int posix_cpu_timer_set(struct k_itimer *timer, int flags,
}
}
- 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
@@ -794,8 +795,6 @@ int posix_cpu_timer_set(struct k_itimer *timer, int flags,
* it as an overrun (thanks to bump_cpu_timer above).
*/
read_unlock(&tasklist_lock);
- timer->it.cpu.firing = -1;
- ret = TIMER_RETRY;
goto out;
}
@@ -961,14 +960,16 @@ void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
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;
}
@@ -977,12 +978,13 @@ static void check_thread_timers(struct task_struct *tsk,
}
++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;
}
@@ -991,12 +993,13 @@ static void check_thread_timers(struct task_struct *tsk,
}
++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;
}
@@ -1013,6 +1016,7 @@ static void check_thread_timers(struct task_struct *tsk,
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;
@@ -1045,12 +1049,13 @@ static void check_process_timers(struct task_struct *tsk,
} 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;
}
@@ -1059,12 +1064,13 @@ static void check_process_timers(struct task_struct *tsk,
}
++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;
}
@@ -1073,12 +1079,13 @@ static void check_process_timers(struct task_struct *tsk,
}
++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;
}
@@ -1161,6 +1168,9 @@ static void check_process_timers(struct task_struct *tsk,
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);
@@ -1197,7 +1207,7 @@ static void check_process_timers(struct task_struct *tsk,
do {
t = next_thread(t);
- } while (unlikely(t->exit_state));
+ } while (unlikely(t->flags & PF_EXITING));
} while (t != tsk);
}
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-15 06:02:19 +0000