Messages in this thread Patch in this message | | | From | Thomas Gleixner <> | Subject | [patch V2 13/50] posix-cpu-timers: Do not arm SIGEV_NONE timers | Date | Thu, 11 Apr 2024 00:46:34 +0200 (CEST) |
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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> --- V2: Split out into new patch to make review simpler - Frederic --- kernel/time/posix-cpu-timers.c | 29 +++++++++++++---------------- 1 file changed, 13 insertions(+), 16 deletions(-)
--- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -584,12 +584,7 @@ static void cpu_timer_fire(struct k_itim { 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 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_ 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_ 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_ 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
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