[patch 11/26] posix-timers: Store k_clock pointer in k_itimer

From: Thomas Gleixner
Date: Tue May 30 2017 - 17:45:49 EST


Having the k_clock pointer in the k_itimer struct avoids the lookup in
several code pathes and makes the next steps of unification of the hrtimer
and alarmtimer based posix timers simpler.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
include/linux/posix-timers.h | 2 ++
kernel/time/posix-cpu-timers.c | 2 ++
kernel/time/posix-timers.c | 7 ++++---
3 files changed, 8 insertions(+), 3 deletions(-)

--- a/include/linux/posix-timers.h
+++ b/include/linux/posix-timers.h
@@ -55,6 +55,7 @@ struct cpu_timer_list {
* @list: List head for binding the timer to signals->posix_timers
* @t_hash: Entry in the posix timer hash table
* @it_lock: Lock protecting the timer
+ * @kclock: Pointer to the k_clock struct handling this timer
* @it_clock: The posix timer clock id
* @it_id: The posix timer id for identifying the timer
* @it_overrun: The overrun counter for pending signals
@@ -74,6 +75,7 @@ struct k_itimer {
struct list_head list;
struct hlist_node t_hash;
spinlock_t it_lock;
+ const struct k_clock *kclock;
clockid_t it_clock;
timer_t it_id;
int it_overrun;
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -324,6 +324,8 @@ static int posix_cpu_timer_create(struct
if (CPUCLOCK_WHICH(new_timer->it_clock) >= CPUCLOCK_MAX)
return -EINVAL;

+ new_timer->kclock = &clock_posix_cpu;
+
INIT_LIST_HEAD(&new_timer->it.cpu.entry);

rcu_read_lock();
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -519,6 +519,7 @@ SYSCALL_DEFINE3(timer_create, const cloc
it_id_set = IT_ID_SET;
new_timer->it_id = (timer_t) new_timer_id;
new_timer->it_clock = which_clock;
+ new_timer->kclock = kc;
new_timer->it_overrun = -1;

if (timer_event_spec) {
@@ -679,7 +680,7 @@ SYSCALL_DEFINE2(timer_gettime, timer_t,
if (!timr)
return -EINVAL;

- kc = clockid_to_kclock(timr->it_clock);
+ kc = timr->kclock;
if (WARN_ON_ONCE(!kc || !kc->timer_get))
ret = -EINVAL;
else
@@ -798,7 +799,7 @@ SYSCALL_DEFINE4(timer_settime, timer_t,
if (!timr)
return -EINVAL;

- kc = clockid_to_kclock(timr->it_clock);
+ kc = timr->kclock;
if (WARN_ON_ONCE(!kc || !kc->timer_set))
error = -EINVAL;
else
@@ -829,7 +830,7 @@ static int common_timer_del(struct k_iti

static inline int timer_delete_hook(struct k_itimer *timer)
{
- const struct k_clock *kc = clockid_to_kclock(timer->it_clock);
+ const struct k_clock *kc = timer->kclock;

if (WARN_ON_ONCE(!kc || !kc->timer_del))
return -EINVAL;