diff options
Diffstat (limited to 'kernel/posix-cpu-timers.c')
| -rw-r--r-- | kernel/posix-cpu-timers.c | 127 |
1 files changed, 103 insertions, 24 deletions
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index a278cad1d5d..42670e9b44e 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -10,6 +10,8 @@ #include <linux/kernel_stat.h> #include <trace/events/timer.h> #include <linux/random.h> +#include <linux/tick.h> +#include <linux/workqueue.h> /* * Called after updating RLIMIT_CPU to run cpu timer and update @@ -153,13 +155,36 @@ static void bump_cpu_timer(struct k_itimer *timer, } } +/** + * task_cputime_zero - Check a task_cputime struct for all zero fields. + * + * @cputime: The struct to compare. + * + * Checks @cputime to see if all fields are zero. Returns true if all fields + * are zero, false if any field is nonzero. + */ +static inline int task_cputime_zero(const struct task_cputime *cputime) +{ + if (!cputime->utime && !cputime->stime && !cputime->sum_exec_runtime) + return 1; + return 0; +} + static inline cputime_t prof_ticks(struct task_struct *p) { - return p->utime + p->stime; + cputime_t utime, stime; + + task_cputime(p, &utime, &stime); + + return utime + stime; } static inline cputime_t virt_ticks(struct task_struct *p) { - return p->utime; + cputime_t utime; + + task_cputime(p, &utime, NULL); + + return utime; } static int @@ -471,18 +496,23 @@ static void cleanup_timers(struct list_head *head, */ void posix_cpu_timers_exit(struct task_struct *tsk) { + cputime_t utime, stime; + add_device_randomness((const void*) &tsk->se.sum_exec_runtime, sizeof(unsigned long long)); + task_cputime(tsk, &utime, &stime); cleanup_timers(tsk->cpu_timers, - tsk->utime, tsk->stime, tsk->se.sum_exec_runtime); + utime, stime, tsk->se.sum_exec_runtime); } void posix_cpu_timers_exit_group(struct task_struct *tsk) { struct signal_struct *const sig = tsk->signal; + cputime_t utime, stime; + task_cputime(tsk, &utime, &stime); cleanup_timers(tsk->signal->cpu_timers, - tsk->utime + sig->utime, tsk->stime + sig->stime, + utime + sig->utime, stime + sig->stime, tsk->se.sum_exec_runtime + sig->sum_sched_runtime); } @@ -623,6 +653,37 @@ static int cpu_timer_sample_group(const clockid_t which_clock, return 0; } +#ifdef CONFIG_NO_HZ_FULL +static void nohz_kick_work_fn(struct work_struct *work) +{ + tick_nohz_full_kick_all(); +} + +static DECLARE_WORK(nohz_kick_work, nohz_kick_work_fn); + +/* + * We need the IPIs to be sent from sane process context. + * The posix cpu timers are always set with irqs disabled. + */ +static void posix_cpu_timer_kick_nohz(void) +{ + schedule_work(&nohz_kick_work); +} + +bool posix_cpu_timers_can_stop_tick(struct task_struct *tsk) +{ + if (!task_cputime_zero(&tsk->cputime_expires)) + return false; + + if (tsk->signal->cputimer.running) + return false; + + return true; +} +#else +static inline void posix_cpu_timer_kick_nohz(void) { } +#endif + /* * Guts of sys_timer_settime for CPU timers. * This is called with the timer locked and interrupts disabled. @@ -781,6 +842,8 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int flags, sample_to_timespec(timer->it_clock, old_incr, &old->it_interval); } + if (!ret) + posix_cpu_timer_kick_nohz(); return ret; } @@ -995,21 +1058,6 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, } } -/** - * task_cputime_zero - Check a task_cputime struct for all zero fields. - * - * @cputime: The struct to compare. - * - * Checks @cputime to see if all fields are zero. Returns true if all fields - * are zero, false if any field is nonzero. - */ -static inline int task_cputime_zero(const struct task_cputime *cputime) -{ - if (!cputime->utime && !cputime->stime && !cputime->sum_exec_runtime) - return 1; - return 0; -} - /* * Check for any per-thread CPU timers that have fired and move them * off the tsk->*_timers list onto the firing list. Per-thread timers @@ -1226,11 +1274,14 @@ static inline int task_cputime_expired(const struct task_cputime *sample, static inline int fastpath_timer_check(struct task_struct *tsk) { struct signal_struct *sig; + cputime_t utime, stime; + + task_cputime(tsk, &utime, &stime); if (!task_cputime_zero(&tsk->cputime_expires)) { struct task_cputime task_sample = { - .utime = tsk->utime, - .stime = tsk->stime, + .utime = utime, + .stime = stime, .sum_exec_runtime = tsk->se.sum_exec_runtime }; @@ -1320,6 +1371,13 @@ void run_posix_cpu_timers(struct task_struct *tsk) cpu_timer_fire(timer); spin_unlock(&timer->it_lock); } + + /* + * In case some timers were rescheduled after the queue got emptied, + * wake up full dynticks CPUs. + */ + if (tsk->signal->cputimer.running) + posix_cpu_timer_kick_nohz(); } /* @@ -1350,7 +1408,7 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, } if (!*newval) - return; + goto out; *newval += now.cpu; } @@ -1368,6 +1426,8 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, tsk->signal->cputime_expires.virt_exp = *newval; break; } +out: + posix_cpu_timer_kick_nohz(); } static int do_cpu_nanosleep(const clockid_t which_clock, int flags, @@ -1401,8 +1461,10 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags, while (!signal_pending(current)) { if (timer.it.cpu.expires.sched == 0) { /* - * Our timer fired and was reset. + * Our timer fired and was reset, below + * deletion can not fail. */ + posix_cpu_timer_del(&timer); spin_unlock_irq(&timer.it_lock); return 0; } @@ -1420,9 +1482,26 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags, * We were interrupted by a signal. */ sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp); - posix_cpu_timer_set(&timer, 0, &zero_it, it); + error = posix_cpu_timer_set(&timer, 0, &zero_it, it); + if (!error) { + /* + * Timer is now unarmed, deletion can not fail. + */ + posix_cpu_timer_del(&timer); + } spin_unlock_irq(&timer.it_lock); + while (error == TIMER_RETRY) { + /* + * We need to handle case when timer was or is in the + * middle of firing. In other cases we already freed + * resources. + */ + spin_lock_irq(&timer.it_lock); + error = posix_cpu_timer_del(&timer); + spin_unlock_irq(&timer.it_lock); + } + if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) { /* * It actually did fire already. |