[PATCH 6/2] posix-cpu-timers: timer functions must use timer timeinstead of clock time

From: KOSAKI Motohiro
Date: Mon Apr 29 2013 - 15:20:46 EST


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.

This is not big matter because following workaround code in
posix_cpu_timer_get() hide the timer inversion 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.motohiro@xxxxxxxxxxxxxx>
---
kernel/posix-cpu-timers.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 9088023..472394b 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -700,7 +700,7 @@ 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)) {
- do_cpu_clock_sample(timer->it_clock, p, false, &val);
+ cpu_timer_sample(timer->it_clock, p, &val);
} else {
cpu_timer_sample_group(timer->it_clock, p, &val);
}
@@ -840,7 +840,7 @@ 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);
@@ -1165,7 +1165,7 @@ 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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