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posix-cpu-timers: Do not arm SIGEV_NONE timers

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There is no point in arming SIGEV_NONE timers as they never deliver a
signal. timer_gettime() is handling the expiry time correctly and that's
all SIGEV_NONE timers care about.

Prevent arming them and remove the expiry handler code which just disarms
them.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
This commit is contained in:
Thomas Gleixner 2024-06-10 18:42:21 +02:00 committed by Frederic Weisbecker
parent d471ff397c
commit bd29d773ea
1 changed files with 13 additions and 16 deletions
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29
kernel/time/posix-cpu-timers.c
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@ -584,12 +584,7 @@ static void cpu_timer_fire(struct k_itimer *timer)
{
struct cpu_timer *ctmr = &timer->it.cpu;
if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) {
/*
* User don't want any signal.
*/
cpu_timer_setexpires(ctmr, 0);
} else if (unlikely(timer->sigq == NULL)) {
if (unlikely(timer->sigq == NULL)) {
/*
* This a special case for clock_nanosleep,
* not a normal timer from sys_timer_create.
@ -625,6 +620,7 @@ static void __posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec64 *i
static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
struct itimerspec64 *new, struct itimerspec64 *old)
{
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;
struct cpu_timer *ctmr = &timer->it.cpu;
@ -688,7 +684,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
if (CPUCLOCK_PERTHREAD(timer->it_clock))
val = cpu_clock_sample(clkid, p);
else
val = cpu_clock_sample_group(clkid, p, true);
val = cpu_clock_sample_group(clkid, p, !sigev_none);
/* Retrieve the previous expiry value if requested. */
if (old) {
@ -708,19 +704,20 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
goto out;
}
if (new_expires != 0 && !(timer_flags & TIMER_ABSTIME)) {
/* Convert relative expiry time to absolute */
if (new_expires && !(timer_flags & TIMER_ABSTIME))
new_expires += val;
}
/* Set the new expiry time (might be 0) */
cpu_timer_setexpires(ctmr, new_expires);
/*
* Install the new expiry time (or zero).
* For a timer with no notification action, we don't actually
* arm the timer (we'll just fake it for timer_gettime).
* Arm the timer if it is not disabled, the new expiry value has
* not yet expired and the timer requires signal delivery.
* SIGEV_NONE timers are never armed.
*/
cpu_timer_setexpires(ctmr, new_expires);
if (new_expires != 0 && val < new_expires) {
if (!sigev_none && new_expires && val < new_expires)
arm_timer(timer, p);
}
unlock_task_sighand(p, &flags);
/*
@ -739,7 +736,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
timer->it_overrun_last = 0;
timer->it_overrun = -1;
if (val >= new_expires) {
if (!sigev_none && val >= new_expires) {
if (new_expires != 0) {
/*
* The designated time already passed, so we notify