From 1cd07c0b94f2c320270d76edb7dd49bceb09c1df Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 21 Aug 2019 21:09:20 +0200 Subject: posix-cpu-timers: Consolidate timer expiry further With the array based samples and expiry cache, the expiry function can use a loop to collect timers from the clock specific lists. Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lkml.kernel.org/r/20190821192922.365469982@linutronix.de --- kernel/time/posix-cpu-timers.c | 63 ++++++++++++++++++++---------------------- 1 file changed, 30 insertions(+), 33 deletions(-) (limited to 'kernel/time') diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index cf85292575c5..caafdfdd6f0f 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -752,6 +752,18 @@ check_timers_list(struct list_head *timers, return U64_MAX; } +static void collect_posix_cputimers(struct posix_cputimers *pct, + u64 *samples, struct list_head *firing) +{ + struct posix_cputimer_base *base = pct->bases; + int i; + + for (i = 0; i < CPUCLOCK_MAX; i++, base++) { + base->nextevt = check_timers_list(&base->cpu_timers, firing, + samples[i]); + } +} + static inline void check_dl_overrun(struct task_struct *tsk) { if (tsk->dl.dl_overrun) { @@ -768,25 +780,18 @@ static inline void check_dl_overrun(struct task_struct *tsk) static void check_thread_timers(struct task_struct *tsk, struct list_head *firing) { - struct posix_cputimer_base *base = tsk->posix_cputimers.bases; + struct posix_cputimers *pct = &tsk->posix_cputimers; + u64 samples[CPUCLOCK_MAX]; unsigned long soft; - u64 stime, utime; if (dl_task(tsk)) check_dl_overrun(tsk); - if (expiry_cache_is_inactive(&tsk->posix_cputimers)) + if (expiry_cache_is_inactive(pct)) return; - task_cputime(tsk, &utime, &stime); - - base->nextevt = check_timers_list(&base->cpu_timers, firing, - utime + stime); - base++; - base->nextevt = check_timers_list(&base->cpu_timers, firing, utime); - base++; - base->nextevt = check_timers_list(&base->cpu_timers, firing, - tsk->se.sum_exec_runtime); + task_sample_cputime(tsk, samples); + collect_posix_cputimers(pct, samples, firing); /* * Check for the special case thread timers. @@ -825,7 +830,7 @@ static void check_thread_timers(struct task_struct *tsk, } } - if (expiry_cache_is_inactive(&tsk->posix_cputimers)) + if (expiry_cache_is_inactive(pct)) tick_dep_clear_task(tsk, TICK_DEP_BIT_POSIX_TIMER); } @@ -869,15 +874,15 @@ static void check_process_timers(struct task_struct *tsk, struct list_head *firing) { struct signal_struct *const sig = tsk->signal; - struct posix_cputimer_base *base = sig->posix_cputimers.bases; - u64 virt_exp, prof_exp, sched_exp, samples[CPUCLOCK_MAX]; + struct posix_cputimers *pct = &sig->posix_cputimers; + u64 samples[CPUCLOCK_MAX]; unsigned long soft; /* * If cputimer is not running, then there are no active * process wide timers (POSIX 1.b, itimers, RLIMIT_CPU). */ - if (!READ_ONCE(tsk->signal->cputimer.running)) + if (!READ_ONCE(sig->cputimer.running)) return; /* @@ -891,21 +896,17 @@ static void check_process_timers(struct task_struct *tsk, * so the sample can be taken directly. */ proc_sample_cputime_atomic(&sig->cputimer.cputime_atomic, samples); - - prof_exp = check_timers_list(&base[CPUCLOCK_PROF].cpu_timers, - firing, samples[CPUCLOCK_PROF]); - virt_exp = check_timers_list(&base[CPUCLOCK_VIRT].cpu_timers, - firing, samples[CPUCLOCK_VIRT]); - sched_exp = check_timers_list(&base[CPUCLOCK_SCHED].cpu_timers, - firing, samples[CPUCLOCK_SCHED]); + collect_posix_cputimers(pct, samples, firing); /* * Check for the special case process timers. */ - check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_exp, + check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], + &pct->bases[CPUCLOCK_PROF].nextevt, samples[CPUCLOCK_PROF], SIGPROF); - check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_exp, - samples[CPUCLOCK_PROF], SIGVTALRM); + check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], + &pct->bases[CPUCLOCK_VIRT].nextevt, + samples[CPUCLOCK_VIRT], SIGVTALRM); soft = task_rlimit(tsk, RLIMIT_CPU); if (soft != RLIM_INFINITY) { @@ -940,15 +941,11 @@ static void check_process_timers(struct task_struct *tsk, } } softns = soft * NSEC_PER_SEC; - if (softns < prof_exp) - prof_exp = softns; + if (softns < pct->bases[CPUCLOCK_PROF].nextevt) + pct->bases[CPUCLOCK_PROF].nextevt = softns; } - base[CPUCLOCK_PROF].nextevt = prof_exp; - base[CPUCLOCK_VIRT].nextevt = virt_exp; - base[CPUCLOCK_SCHED].nextevt = sched_exp; - - if (expiry_cache_is_inactive(&sig->posix_cputimers)) + if (expiry_cache_is_inactive(pct)) stop_process_timers(sig); sig->cputimer.checking_timer = false; -- cgit v1.2.3-59-g8ed1b