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posix-cpu-timers: Consolidate timer expiry further

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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 <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192922.365469982@linutronix.de
This commit is contained in:
Thomas Gleixner 2019-08-21 21:09:20 +02:00
parent 2bbdbdae05
commit 1cd07c0b94
1 changed files with 30 additions and 33 deletions
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63
kernel/time/posix-cpu-timers.c
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@ -752,6 +752,18 @@ check_timers_list(struct list_head *timers,
return U64_MAX; 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) static inline void check_dl_overrun(struct task_struct *tsk)
{ {
if (tsk->dl.dl_overrun) { 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, static void check_thread_timers(struct task_struct *tsk,
struct list_head *firing) 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; unsigned long soft;
u64 stime, utime;
if (dl_task(tsk)) if (dl_task(tsk))
check_dl_overrun(tsk); check_dl_overrun(tsk);
if (expiry_cache_is_inactive(&tsk->posix_cputimers)) if (expiry_cache_is_inactive(pct))
return; return;
task_cputime(tsk, &utime, &stime); task_sample_cputime(tsk, samples);
collect_posix_cputimers(pct, samples, firing);
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);
/* /*
* Check for the special case thread timers. * 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); 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 list_head *firing)
{ {
struct signal_struct *const sig = tsk->signal; struct signal_struct *const sig = tsk->signal;
struct posix_cputimer_base *base = sig->posix_cputimers.bases; struct posix_cputimers *pct = &sig->posix_cputimers;
u64 virt_exp, prof_exp, sched_exp, samples[CPUCLOCK_MAX]; u64 samples[CPUCLOCK_MAX];
unsigned long soft; unsigned long soft;
/* /*
* If cputimer is not running, then there are no active * If cputimer is not running, then there are no active
* process wide timers (POSIX 1.b, itimers, RLIMIT_CPU). * process wide timers (POSIX 1.b, itimers, RLIMIT_CPU).
*/ */
if (!READ_ONCE(tsk->signal->cputimer.running)) if (!READ_ONCE(sig->cputimer.running))
return; return;
/* /*
@ -891,21 +896,17 @@ static void check_process_timers(struct task_struct *tsk,
* so the sample can be taken directly. * so the sample can be taken directly.
*/ */
proc_sample_cputime_atomic(&sig->cputimer.cputime_atomic, samples); proc_sample_cputime_atomic(&sig->cputimer.cputime_atomic, samples);
collect_posix_cputimers(pct, samples, firing);
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]);
/* /*
* Check for the special case process timers. * 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); samples[CPUCLOCK_PROF], SIGPROF);
check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_exp, check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT],
samples[CPUCLOCK_PROF], SIGVTALRM); &pct->bases[CPUCLOCK_VIRT].nextevt,
samples[CPUCLOCK_VIRT], SIGVTALRM);
soft = task_rlimit(tsk, RLIMIT_CPU); soft = task_rlimit(tsk, RLIMIT_CPU);
if (soft != RLIM_INFINITY) { if (soft != RLIM_INFINITY) {
@ -940,15 +941,11 @@ static void check_process_timers(struct task_struct *tsk,
} }
} }
softns = soft * NSEC_PER_SEC; softns = soft * NSEC_PER_SEC;
if (softns < prof_exp) if (softns < pct->bases[CPUCLOCK_PROF].nextevt)
prof_exp = softns; pct->bases[CPUCLOCK_PROF].nextevt = softns;
} }
base[CPUCLOCK_PROF].nextevt = prof_exp; if (expiry_cache_is_inactive(pct))
base[CPUCLOCK_VIRT].nextevt = virt_exp;
base[CPUCLOCK_SCHED].nextevt = sched_exp;
if (expiry_cache_is_inactive(&sig->posix_cputimers))
stop_process_timers(sig); stop_process_timers(sig);
sig->cputimer.checking_timer = false; sig->cputimer.checking_timer = false;