[tip:timers/core] posix-timers: Move interval out of the union

tip-bot for Thomas Gleixner
2017-06-05T08:20:38Z

Commit-ID: 80105cd0e62ba8a2caf8eebd52f42952c7c04046
Gitweb: http://git.kernel.org/tip/80105cd0e62ba8a2caf8eebd52f42952c7c04046
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 30 May 2017 23:15:43 +0200
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Sun, 4 Jun 2017 15:40:24 +0200

posix-timers: Move interval out of the union

Preparatory patch to unify the alarm timer and hrtimer based posix interval
timer handling.

The interval is used as a criteria for rearming decisions so moving it out
of the clock specific data structures allows later unification.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.563922908@linutronix.de

---
include/linux/posix-timers.h | 4 ++--
kernel/time/alarmtimer.c | 13 ++++++-------
kernel/time/posix-timers.c | 20 ++++++++++----------
3 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h
index a372e7e..908048f 100644
--- a/include/linux/posix-timers.h
+++ b/include/linux/posix-timers.h
@@ -63,6 +63,7 @@ struct cpu_timer_list {
* @it_requeue_pending: Indicator that timer waits for being requeued on
* signal delivery
* @it_sigev_notify: The notify word of sigevent struct for signal delivery
+ * @it_interval: The interval for periodic timers
* @it_signal: Pointer to the creators signal struct
* @it_pid: The pid of the process/task targeted by the signal
* @it_process: The task to wakeup on clock_nanosleep (CPU timers)
@@ -80,6 +81,7 @@ struct k_itimer {
int it_overrun_last;
int it_requeue_pending;
int it_sigev_notify;
+ ktime_t it_interval;
struct signal_struct *it_signal;
union {
struct pid *it_pid;
@@ -89,12 +91,10 @@ struct k_itimer {
union {
struct {
struct hrtimer timer;
- ktime_t interval;
} real;
struct cpu_timer_list cpu;
struct {
struct alarm alarmtimer;
- ktime_t interval;
} alarm;
struct rcu_head rcu;
} it;
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 36855d6..5b8cf4b 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -527,9 +527,8 @@ static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
}

/* Re-add periodic timers */
- if (ptr->it.alarm.interval) {
- ptr->it_overrun += alarm_forward(alarm, now,
- ptr->it.alarm.interval);
+ if (ptr->it_interval) {
+ ptr->it_overrun += alarm_forward(alarm, now, ptr->it_interval);
result = ALARMTIMER_RESTART;
}
spin_unlock_irqrestore(&ptr->it_lock, flags);
@@ -613,7 +612,7 @@ static void alarm_timer_get(struct k_itimer *timr,
cur_setting->it_value.tv_nsec = 0;
}

- cur_setting->it_interval = ktime_to_timespec64(timr->it.alarm.interval);
+ cur_setting->it_interval = ktime_to_timespec64(timr->it_interval);
}

/**
@@ -662,14 +661,14 @@ static int alarm_timer_set(struct k_itimer *timr, int flags,
return TIMER_RETRY;

/* start the timer */
- timr->it.alarm.interval = timespec64_to_ktime(new_setting->it_interval);
+ timr->it_interval = timespec64_to_ktime(new_setting->it_interval);

/*
* Rate limit to the tick as a hot fix to prevent DOS. Will be
* mopped up later.
*/
- if (timr->it.alarm.interval < TICK_NSEC)
- timr->it.alarm.interval = TICK_NSEC;
+ if (timr->it_interval < TICK_NSEC)
+ timr->it_interval = TICK_NSEC;

exp = timespec64_to_ktime(new_setting->it_value);
/* Convert (if necessary) to absolute time */
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 79a00e0..7dd992c 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -285,12 +285,12 @@ static void schedule_next_timer(struct k_itimer *timr)
{
struct hrtimer *timer = &timr->it.real.timer;

- if (timr->it.real.interval == 0)
+ if (!timr->it_interval)
return;

timr->it_overrun += (unsigned int) hrtimer_forward(timer,
timer->base->get_time(),
- timr->it.real.interval);
+ timr->it_interval);
hrtimer_restart(timer);
}

@@ -375,7 +375,7 @@ static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
timr = container_of(timer, struct k_itimer, it.real.timer);
spin_lock_irqsave(&timr->it_lock, flags);

- if (timr->it.real.interval != 0)
+ if (timr->it_interval != 0)
si_private = ++timr->it_requeue_pending;

if (posix_timer_event(timr, si_private)) {
@@ -384,7 +384,7 @@ static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
* we will not get a call back to restart it AND
* it should be restarted.
*/
- if (timr->it.real.interval != 0) {
+ if (timr->it_interval != 0) {
ktime_t now = hrtimer_cb_get_time(timer);

/*
@@ -413,13 +413,13 @@ static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
{
ktime_t kj = NSEC_PER_SEC / HZ;

- if (timr->it.real.interval < kj)
+ if (timr->it_interval < kj)
now = ktime_add(now, kj);
}
#endif
timr->it_overrun += (unsigned int)
hrtimer_forward(timer, now,
- timr->it.real.interval);
+ timr->it_interval);
ret = HRTIMER_RESTART;
++timr->it_requeue_pending;
}
@@ -631,7 +631,7 @@ common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting)

memset(cur_setting, 0, sizeof(*cur_setting));

- iv = timr->it.real.interval;
+ iv = timr->it_interval;

/* interval timer ? */
if (iv)
@@ -732,7 +732,7 @@ common_timer_set(struct k_itimer *timr, int flags,
common_timer_get(timr, old_setting);

/* disable the timer */
- timr->it.real.interval = 0;
+ timr->it_interval = 0;
/*
* careful here. If smp we could be in the "fire" routine which will
* be spinning as we hold the lock. But this is ONLY an SMP issue.
@@ -755,7 +755,7 @@ common_timer_set(struct k_itimer *timr, int flags,
hrtimer_set_expires(timer, timespec64_to_ktime(new_setting->it_value));

/* Convert interval */
- timr->it.real.interval = timespec64_to_ktime(new_setting->it_interval);
+ timr->it_interval = timespec64_to_ktime(new_setting->it_interval);

/* SIGEV_NONE timers are not queued ! See common_timer_get */
if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) {
@@ -820,7 +820,7 @@ retry:

static int common_timer_del(struct k_itimer *timer)
{
- timer->it.real.interval = 0;
+ timer->it_interval = 0;

if (hrtimer_try_to_cancel(&timer->it.real.timer) < 0)
return TIMER_RETRY;