From: KOSAKI Motohiro <kosaki.motoh...@jp.fujitsu.com>
For process timer, we use cpu_clock_sample_group() and cpu_timer_sample_group()
correctly. However for thread timer, we always use cpu_clock_sample().
That's wrong becuase cpu_clock_sample() account uncommited delta_exec too. And
this is inconsistency against run_posix_cpu_tiemrs().
This is not big matter because a following workaround code in
posix_cpu_timer_get() hides the timer miscalculation issue. However it makes
wrong rq lock held and would be better to fix.
if (cpu_time_before(timer->it_clock, now, timer->it.cpu.expires)) {
...
} else {
/*
* The timer should have expired already, but the firing
* hasn't taken place yet. Say it's just about to expire.
*/
itp->it_value.tv_nsec = 1;
itp->it_value.tv_sec = 0;
Signed-off-by: KOSAKI Motohiro <kosaki.motoh...@jp.fujitsu.com>
---
kernel/posix-cpu-timers.c | 37 +++++++++++++++++++++++++++----------
1 files changed, 27 insertions(+), 10 deletions(-)
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 98f354e..c69b8d8 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -204,11 +204,10 @@ posix_cpu_clock_set(const clockid_t which_clock, const
struct timespec *tp)
}
-/*
- * Sample a per-thread clock for the given task.
- */
-static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p,
- union cpu_time_count *cpu)
+static int do_cpu_clock_timer_sample(const clockid_t which_clock,
+ struct task_struct *p,
+ bool add_delta,
+ union cpu_time_count *cpu)
{
switch (CPUCLOCK_WHICH(which_clock)) {
default:
@@ -220,12 +219,30 @@ static int cpu_clock_sample(const clockid_t which_clock,
struct task_struct *p,
cpu->cpu = virt_ticks(p);
break;
case CPUCLOCK_SCHED:
- cpu->sched = task_sched_runtime(p, true);
+ cpu->sched = task_sched_runtime(p, add_delta);
break;
}
return 0;
}
+/*
+ * Sample a per-thread clock for the given task.
+ */
+static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p,
+ union cpu_time_count *cpu)
+{
+ return do_cpu_clock_timer_sample(which_clock, p, true, cpu);
+}
+
+/*
+ * Sample a per-thread timer clock for the given task.
+ */
+static int cpu_timer_sample(const clockid_t which_clock, struct task_struct *p,
+ union cpu_time_count *cpu)
+{
+ return do_cpu_clock_timer_sample(which_clock, p, false, cpu);
+}
+
static void update_gt_cputime(struct task_cputime *a, struct task_cputime *b)
{
if (b->utime > a->utime)
@@ -700,7 +717,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int
flags,
* check if it's already passed. In short, we need a sample.
*/
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
- cpu_clock_sample(timer->it_clock, p, &val);
+ cpu_timer_sample(timer->it_clock, p, &val);
} else {
cpu_timer_sample_group(timer->it_clock, p, &val);
}
@@ -756,7 +773,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int
flags,
* we need exact current time.
*/
if (CPUCLOCK_PERTHREAD(timer->it_clock))
- now = val;
+ cpu_clock_sample(timer->it_clock, p, &now);
else
cpu_clock_sample_group(timer->it_clock, p, &now);
cpu_time_add(timer->it_clock, &new_expires, now);
@@ -844,7 +861,7 @@ static void posix_cpu_timer_get(struct k_itimer *timer,
struct itimerspec *itp)
* Sample the clock to take the difference with the expiry time.
*/
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
- cpu_clock_sample(timer->it_clock, p, &now);
+ cpu_timer_sample(timer->it_clock, p, &now);
clear_dead = p->exit_state;
} else {
read_lock(&tasklist_lock);
@@ -1168,7 +1185,7 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
* Fetch the current sample and update the timer's expiry time.
*/
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
- cpu_clock_sample(timer->it_clock, p, &now);
+ cpu_timer_sample(timer->it_clock, p, &now);
bump_cpu_timer(timer, now);
if (unlikely(p->exit_state)) {
clear_dead_task(timer, now);
--
1.7.1
--
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