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Diffstat (limited to 'kernel/posix-cpu-timers.c')
-rw-r--r--kernel/posix-cpu-timers.c136
1 files changed, 78 insertions, 58 deletions
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index db107c9bbc0..e976e505648 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -261,6 +261,40 @@ out:
rcu_read_unlock();
}
+static void update_gt_cputime(struct task_cputime *a, struct task_cputime *b)
+{
+ if (cputime_gt(b->utime, a->utime))
+ a->utime = b->utime;
+
+ if (cputime_gt(b->stime, a->stime))
+ a->stime = b->stime;
+
+ if (b->sum_exec_runtime > a->sum_exec_runtime)
+ a->sum_exec_runtime = b->sum_exec_runtime;
+}
+
+void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
+{
+ struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
+ struct task_cputime sum;
+ unsigned long flags;
+
+ spin_lock_irqsave(&cputimer->lock, flags);
+ if (!cputimer->running) {
+ cputimer->running = 1;
+ /*
+ * The POSIX timer interface allows for absolute time expiry
+ * values through the TIMER_ABSTIME flag, therefore we have
+ * to synchronize the timer to the clock every time we start
+ * it.
+ */
+ thread_group_cputime(tsk, &sum);
+ update_gt_cputime(&cputimer->cputime, &sum);
+ }
+ *times = cputimer->cputime;
+ spin_unlock_irqrestore(&cputimer->lock, flags);
+}
+
/*
* Sample a process (thread group) clock for the given group_leader task.
* Must be called with tasklist_lock held for reading.
@@ -488,7 +522,7 @@ void posix_cpu_timers_exit_group(struct task_struct *tsk)
{
struct task_cputime cputime;
- thread_group_cputime(tsk, &cputime);
+ thread_group_cputimer(tsk, &cputime);
cleanup_timers(tsk->signal->cpu_timers,
cputime.utime, cputime.stime, cputime.sum_exec_runtime);
}
@@ -507,29 +541,6 @@ static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now)
}
/*
- * Enable the process wide cpu timer accounting.
- *
- * serialized using ->sighand->siglock
- */
-static void start_process_timers(struct task_struct *tsk)
-{
- tsk->signal->cputimer.running = 1;
- barrier();
-}
-
-/*
- * Release the process wide timer accounting -- timer stops ticking when
- * nobody cares about it.
- *
- * serialized using ->sighand->siglock
- */
-static void stop_process_timers(struct task_struct *tsk)
-{
- tsk->signal->cputimer.running = 0;
- barrier();
-}
-
-/*
* Insert the timer on the appropriate list before any timers that
* expire later. This must be called with the tasklist_lock held
* for reading, and interrupts disabled.
@@ -549,9 +560,6 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
BUG_ON(!irqs_disabled());
spin_lock(&p->sighand->siglock);
- if (!CPUCLOCK_PERTHREAD(timer->it_clock))
- start_process_timers(p);
-
listpos = head;
if (CPUCLOCK_WHICH(timer->it_clock) == CPUCLOCK_SCHED) {
list_for_each_entry(next, head, entry) {
@@ -673,6 +681,33 @@ static void cpu_timer_fire(struct k_itimer *timer)
}
/*
+ * Sample a process (thread group) timer for the given group_leader task.
+ * Must be called with tasklist_lock held for reading.
+ */
+static int cpu_timer_sample_group(const clockid_t which_clock,
+ struct task_struct *p,
+ union cpu_time_count *cpu)
+{
+ struct task_cputime cputime;
+
+ thread_group_cputimer(p, &cputime);
+ switch (CPUCLOCK_WHICH(which_clock)) {
+ default:
+ return -EINVAL;
+ case CPUCLOCK_PROF:
+ cpu->cpu = cputime_add(cputime.utime, cputime.stime);
+ break;
+ case CPUCLOCK_VIRT:
+ cpu->cpu = cputime.utime;
+ break;
+ case CPUCLOCK_SCHED:
+ cpu->sched = cputime.sum_exec_runtime + task_delta_exec(p);
+ break;
+ }
+ return 0;
+}
+
+/*
* Guts of sys_timer_settime for CPU timers.
* This is called with the timer locked and interrupts disabled.
* If we return TIMER_RETRY, it's necessary to release the timer's lock
@@ -733,7 +768,7 @@ int posix_cpu_timer_set(struct k_itimer *timer, int flags,
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
cpu_clock_sample(timer->it_clock, p, &val);
} else {
- cpu_clock_sample_group(timer->it_clock, p, &val);
+ cpu_timer_sample_group(timer->it_clock, p, &val);
}
if (old) {
@@ -881,7 +916,7 @@ void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
read_unlock(&tasklist_lock);
goto dead;
} else {
- cpu_clock_sample_group(timer->it_clock, p, &now);
+ cpu_timer_sample_group(timer->it_clock, p, &now);
clear_dead = (unlikely(p->exit_state) &&
thread_group_empty(p));
}
@@ -1021,6 +1056,19 @@ static void check_thread_timers(struct task_struct *tsk,
}
}
+static void stop_process_timers(struct task_struct *tsk)
+{
+ struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
+ unsigned long flags;
+
+ if (!cputimer->running)
+ return;
+
+ spin_lock_irqsave(&cputimer->lock, flags);
+ cputimer->running = 0;
+ spin_unlock_irqrestore(&cputimer->lock, flags);
+}
+
/*
* Check for any per-thread CPU timers that have fired and move them
* off the tsk->*_timers list onto the firing list. Per-thread timers
@@ -1223,7 +1271,7 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
clear_dead_task(timer, now);
goto out_unlock;
}
- cpu_clock_sample_group(timer->it_clock, p, &now);
+ cpu_timer_sample_group(timer->it_clock, p, &now);
bump_cpu_timer(timer, now);
/* Leave the tasklist_lock locked for the call below. */
}
@@ -1388,33 +1436,6 @@ void run_posix_cpu_timers(struct task_struct *tsk)
}
/*
- * Sample a process (thread group) timer for the given group_leader task.
- * Must be called with tasklist_lock held for reading.
- */
-static int cpu_timer_sample_group(const clockid_t which_clock,
- struct task_struct *p,
- union cpu_time_count *cpu)
-{
- struct task_cputime cputime;
-
- thread_group_cputimer(p, &cputime);
- switch (CPUCLOCK_WHICH(which_clock)) {
- default:
- return -EINVAL;
- case CPUCLOCK_PROF:
- cpu->cpu = cputime_add(cputime.utime, cputime.stime);
- break;
- case CPUCLOCK_VIRT:
- cpu->cpu = cputime.utime;
- break;
- case CPUCLOCK_SCHED:
- cpu->sched = cputime.sum_exec_runtime + task_delta_exec(p);
- break;
- }
- return 0;
-}
-
-/*
* Set one of the process-wide special case CPU timers.
* The tsk->sighand->siglock must be held by the caller.
* The *newval argument is relative and we update it to be absolute, *oldval
@@ -1427,7 +1448,6 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
struct list_head *head;
BUG_ON(clock_idx == CPUCLOCK_SCHED);
- start_process_timers(tsk);
cpu_timer_sample_group(clock_idx, tsk, &now);
if (oldval) {