[patch 21/44] posix-cpu-timers: Get rid of pointer indirection

Thomas Gleixner
2019-08-19T15:47:53Z

Now that the sample functions have no return value anymore, the result can
simply be returned instead of using pointer indirection.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/time/posix-cpu-timers.c | 50 ++++++++++++++++++-----------------------
1 file changed, 22 insertions(+), 28 deletions(-)

--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -182,22 +182,19 @@ posix_cpu_clock_set(const clockid_t cloc
/*
* Sample a per-thread clock for the given task. clkid is validated.
*/
-static void cpu_clock_sample(const clockid_t clkid, struct task_struct *p,
- u64 *sample)
+static u64 cpu_clock_sample(const clockid_t clkid, struct task_struct *p)
{
switch (clkid) {
case CPUCLOCK_PROF:
- *sample = prof_ticks(p);
- break;
+ return prof_ticks(p);
case CPUCLOCK_VIRT:
- *sample = virt_ticks(p);
- break;
+ return virt_ticks(p);
case CPUCLOCK_SCHED:
- *sample = task_sched_runtime(p);
- break;
+ return task_sched_runtime(p);
default:
WARN_ON_ONCE(1);
}
+ return 0;
}

/*
@@ -299,8 +296,8 @@ thread_group_start_cputime(struct task_s
* held to protect the task traversal on a full update. clkid is already
* validated.
*/
-static void cpu_clock_sample_group(const clockid_t clkid, struct task_struct *p,
- u64 *sample, bool start)
+static u64 cpu_clock_sample_group(const clockid_t clkid, struct task_struct *p,
+ bool start)
{
struct thread_group_cputimer *cputimer = &p->signal->cputimer;
struct task_cputime cputime;
@@ -316,17 +313,15 @@ static void cpu_clock_sample_group(const

switch (clkid) {
case CPUCLOCK_PROF:
- *sample = cputime.utime + cputime.stime;
- break;
+ return cputime.utime + cputime.stime;
case CPUCLOCK_VIRT:
- *sample = cputime.utime;
- break;
+ return cputime.utime;
case CPUCLOCK_SCHED:
- *sample = cputime.sum_exec_runtime;
- break;
+ return cputime.sum_exec_runtime;
default:
WARN_ON_ONCE(1);
}
+ return 0;
}

static int posix_cpu_clock_get(const clockid_t clock, struct timespec64 *tp)
@@ -340,9 +335,9 @@ static int posix_cpu_clock_get(const clo
return -EINVAL;

if (CPUCLOCK_PERTHREAD(clock))
- cpu_clock_sample(clkid, tsk, &t);
+ t = cpu_clock_sample(clkid, tsk);
else
- cpu_clock_sample_group(clkid, tsk, &t, false);
+ t = cpu_clock_sample_group(clkid, tsk, false);
put_task_struct(tsk);

*tp = ns_to_timespec64(t);
@@ -604,11 +599,10 @@ static int posix_cpu_timer_set(struct k_
* times (in arm_timer). With an absolute time, we must
* check if it's already passed. In short, we need a sample.
*/
- if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
- cpu_clock_sample(clkid, p, &val);
- } else {
- cpu_clock_sample_group(clkid, p, &val, true);
- }
+ if (CPUCLOCK_PERTHREAD(timer->it_clock))
+ val = cpu_clock_sample(clkid, p);
+ else
+ val = cpu_clock_sample_group(clkid, p, true);

if (old) {
if (old_expires == 0) {
@@ -716,7 +710,7 @@ static void posix_cpu_timer_get(struct k
* Sample the clock to take the difference with the expiry time.
*/
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
- cpu_clock_sample(clkid, p, &now);
+ now = cpu_clock_sample(clkid, p);
} else {
struct sighand_struct *sighand;
unsigned long flags;
@@ -736,7 +730,7 @@ static void posix_cpu_timer_get(struct k
timer->it.cpu.expires = 0;
return;
} else {
- cpu_clock_sample_group(clkid, p, &now, false);
+ now = cpu_clock_sample_group(clkid, p, false);
unlock_task_sighand(p, &flags);
}
}
@@ -998,7 +992,7 @@ static void posix_cpu_timer_rearm(struct
* Fetch the current sample and update the timer's expiry time.
*/
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
- cpu_clock_sample(clkid, p, &now);
+ now = cpu_clock_sample(clkid, p);
bump_cpu_timer(timer, now);
if (unlikely(p->exit_state))
return;
@@ -1024,7 +1018,7 @@ static void posix_cpu_timer_rearm(struct
/* If the process is dying, no need to rearm */
goto unlock;
}
- cpu_clock_sample_group(clkid, p, &now, true);
+ now = cpu_clock_sample_group(clkid, p, true);
bump_cpu_timer(timer, now);
/* Leave the sighand locked for the call below. */
}
@@ -1206,7 +1200,7 @@ void set_process_cpu_timer(struct task_s
if (WARN_ON_ONCE(clock_idx >= CPUCLOCK_SCHED))
return;

- cpu_clock_sample_group(clock_idx, tsk, &now, true);
+ now = cpu_clock_sample_group(clock_idx, tsk, true);

if (oldval) {
/*