[patch V2 14/50] posix-cpu-timers: Use @now instead of @val for clarity

From: Thomas Gleixner
Date: Wed Apr 10 2024 - 18:49:17 EST


posix_cpu_timer_set() uses @val as variable for the current time. That's
confusing at best.

Use @now as anywhere else and rewrite the confusing comment about clock
sampling.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
---
kernel/time/posix-cpu-timers.c | 22 +++++++++-------------
1 file changed, 9 insertions(+), 13 deletions(-)

--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -622,7 +622,7 @@ static int posix_cpu_timer_set(struct k_
{
bool sigev_none = timer->it_sigev_notify == SIGEV_NONE;
clockid_t clkid = CPUCLOCK_WHICH(timer->it_clock);
- u64 old_expires, new_expires, old_incr, val;
+ u64 old_expires, new_expires, old_incr, now;
struct cpu_timer *ctmr = &timer->it.cpu;
struct sighand_struct *sighand;
struct task_struct *p;
@@ -674,23 +674,19 @@ static int posix_cpu_timer_set(struct k_
}

/*
- * We need to sample the current value to convert the new
- * value from to relative and absolute, and to convert the
- * old value from absolute to relative. To set a process
- * timer, we need a sample to balance the thread expiry
- * times (in arm_timer). With an absolute time, we must
- * check if it's already passed. In short, we need a sample.
+ * Sample the current clock for saving the previous setting
+ * and for rearming the timer.
*/
if (CPUCLOCK_PERTHREAD(timer->it_clock))
- val = cpu_clock_sample(clkid, p);
+ now = cpu_clock_sample(clkid, p);
else
- val = cpu_clock_sample_group(clkid, p, !sigev_none);
+ now = cpu_clock_sample_group(clkid, p, !sigev_none);

/* Retrieve the previous expiry value if requested. */
if (old) {
old->it_value = (struct timespec64){ };
if (old_expires)
- __posix_cpu_timer_get(timer, old, val);
+ __posix_cpu_timer_get(timer, old, now);
}

if (unlikely(ret)) {
@@ -706,7 +702,7 @@ static int posix_cpu_timer_set(struct k_

/* Convert relative expiry time to absolute */
if (new_expires && !(timer_flags & TIMER_ABSTIME))
- new_expires += val;
+ new_expires += now;

/* Set the new expiry time (might be 0) */
cpu_timer_setexpires(ctmr, new_expires);
@@ -716,7 +712,7 @@ static int posix_cpu_timer_set(struct k_
* not yet expired and the timer requires signal delivery.
* SIGEV_NONE timers are never armed.
*/
- if (!sigev_none && new_expires && val < new_expires)
+ if (!sigev_none && new_expires && now < new_expires)
arm_timer(timer, p);

unlock_task_sighand(p, &flags);
@@ -736,7 +732,7 @@ static int posix_cpu_timer_set(struct k_
timer->it_overrun_last = 0;
timer->it_overrun = -1;

- if (!sigev_none && val >= new_expires) {
+ if (!sigev_none && now >= new_expires) {
if (new_expires != 0) {
/*
* The designated time already passed, so we notify