diff options
Diffstat (limited to 'kernel/time')
| -rw-r--r-- | kernel/time/Kconfig | 1 | ||||
| -rw-r--r-- | kernel/time/posix-timers.c | 29 | ||||
| -rw-r--r-- | kernel/time/tick-sched.c | 32 | ||||
| -rw-r--r-- | kernel/time/timer.c | 35 |
4 files changed, 72 insertions, 25 deletions
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig index e776fc8cc1df..f6b5f19223d6 100644 --- a/kernel/time/Kconfig +++ b/kernel/time/Kconfig @@ -95,6 +95,7 @@ config NO_HZ_FULL select RCU_NOCB_CPU select VIRT_CPU_ACCOUNTING_GEN select IRQ_WORK + select CPU_ISOLATION help Adaptively try to shutdown the tick whenever possible, even when the CPU is running tasks. Typically this requires running a single diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c index 13d6881f908b..ec999f32c840 100644 --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -434,17 +434,22 @@ static struct pid *good_sigevent(sigevent_t * event) { struct task_struct *rtn = current->group_leader; - if ((event->sigev_notify & SIGEV_THREAD_ID ) && - (!(rtn = find_task_by_vpid(event->sigev_notify_thread_id)) || - !same_thread_group(rtn, current) || - (event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL)) + switch (event->sigev_notify) { + case SIGEV_SIGNAL | SIGEV_THREAD_ID: + rtn = find_task_by_vpid(event->sigev_notify_thread_id); + if (!rtn || !same_thread_group(rtn, current)) + return NULL; + /* FALLTHRU */ + case SIGEV_SIGNAL: + case SIGEV_THREAD: + if (event->sigev_signo <= 0 || event->sigev_signo > SIGRTMAX) + return NULL; + /* FALLTHRU */ + case SIGEV_NONE: + return task_pid(rtn); + default: return NULL; - - if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) && - ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX))) - return NULL; - - return task_pid(rtn); + } } static struct k_itimer * alloc_posix_timer(void) @@ -669,7 +674,7 @@ void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting) struct timespec64 ts64; bool sig_none; - sig_none = (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE; + sig_none = timr->it_sigev_notify == SIGEV_NONE; iv = timr->it_interval; /* interval timer ? */ @@ -856,7 +861,7 @@ int common_timer_set(struct k_itimer *timr, int flags, timr->it_interval = timespec64_to_ktime(new_setting->it_interval); expires = timespec64_to_ktime(new_setting->it_value); - sigev_none = (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE; + sigev_none = timr->it_sigev_notify == SIGEV_NONE; kc->timer_arm(timr, expires, flags & TIMER_ABSTIME, sigev_none); timr->it_active = !sigev_none; diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 99578f06c8d4..f7cc7abfcf25 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -650,6 +650,11 @@ static void tick_nohz_restart(struct tick_sched *ts, ktime_t now) ts->next_tick = 0; } +static inline bool local_timer_softirq_pending(void) +{ + return local_softirq_pending() & TIMER_SOFTIRQ; +} + static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, ktime_t now, int cpu) { @@ -666,8 +671,18 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, } while (read_seqretry(&jiffies_lock, seq)); ts->last_jiffies = basejiff; - if (rcu_needs_cpu(basemono, &next_rcu) || - arch_needs_cpu() || irq_work_needs_cpu()) { + /* + * Keep the periodic tick, when RCU, architecture or irq_work + * requests it. + * Aside of that check whether the local timer softirq is + * pending. If so its a bad idea to call get_next_timer_interrupt() + * because there is an already expired timer, so it will request + * immeditate expiry, which rearms the hardware timer with a + * minimal delta which brings us back to this place + * immediately. Lather, rinse and repeat... + */ + if (rcu_needs_cpu(basemono, &next_rcu) || arch_needs_cpu() || + irq_work_needs_cpu() || local_timer_softirq_pending()) { next_tick = basemono + TICK_NSEC; } else { /* @@ -986,6 +1001,19 @@ ktime_t tick_nohz_get_sleep_length(void) } /** + * tick_nohz_get_idle_calls_cpu - return the current idle calls counter value + * for a particular CPU. + * + * Called from the schedutil frequency scaling governor in scheduler context. + */ +unsigned long tick_nohz_get_idle_calls_cpu(int cpu) +{ + struct tick_sched *ts = tick_get_tick_sched(cpu); + + return ts->idle_calls; +} + +/** * tick_nohz_get_idle_calls - return the current idle calls counter value * * Called from the schedutil frequency scaling governor in scheduler context. diff --git a/kernel/time/timer.c b/kernel/time/timer.c index ffebcf878fba..89a9e1b4264a 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -823,11 +823,10 @@ static inline struct timer_base *get_timer_cpu_base(u32 tflags, u32 cpu) struct timer_base *base = per_cpu_ptr(&timer_bases[BASE_STD], cpu); /* - * If the timer is deferrable and nohz is active then we need to use - * the deferrable base. + * If the timer is deferrable and NO_HZ_COMMON is set then we need + * to use the deferrable base. */ - if (IS_ENABLED(CONFIG_NO_HZ_COMMON) && base->nohz_active && - (tflags & TIMER_DEFERRABLE)) + if (IS_ENABLED(CONFIG_NO_HZ_COMMON) && (tflags & TIMER_DEFERRABLE)) base = per_cpu_ptr(&timer_bases[BASE_DEF], cpu); return base; } @@ -837,11 +836,10 @@ static inline struct timer_base *get_timer_this_cpu_base(u32 tflags) struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]); /* - * If the timer is deferrable and nohz is active then we need to use - * the deferrable base. + * If the timer is deferrable and NO_HZ_COMMON is set then we need + * to use the deferrable base. */ - if (IS_ENABLED(CONFIG_NO_HZ_COMMON) && base->nohz_active && - (tflags & TIMER_DEFERRABLE)) + if (IS_ENABLED(CONFIG_NO_HZ_COMMON) && (tflags & TIMER_DEFERRABLE)) base = this_cpu_ptr(&timer_bases[BASE_DEF]); return base; } @@ -1009,8 +1007,6 @@ __mod_timer(struct timer_list *timer, unsigned long expires, unsigned int option if (!ret && (options & MOD_TIMER_PENDING_ONLY)) goto out_unlock; - debug_activate(timer, expires); - new_base = get_target_base(base, timer->flags); if (base != new_base) { @@ -1034,6 +1030,8 @@ __mod_timer(struct timer_list *timer, unsigned long expires, unsigned int option } } + debug_activate(timer, expires); + timer->expires = expires; /* * If 'idx' was calculated above and the base time did not advance @@ -1684,7 +1682,7 @@ static __latent_entropy void run_timer_softirq(struct softirq_action *h) base->must_forward_clk = false; __run_timers(base); - if (IS_ENABLED(CONFIG_NO_HZ_COMMON) && base->nohz_active) + if (IS_ENABLED(CONFIG_NO_HZ_COMMON)) __run_timers(this_cpu_ptr(&timer_bases[BASE_DEF])); } @@ -1855,6 +1853,21 @@ static void migrate_timer_list(struct timer_base *new_base, struct hlist_head *h } } +int timers_prepare_cpu(unsigned int cpu) +{ + struct timer_base *base; + int b; + + for (b = 0; b < NR_BASES; b++) { + base = per_cpu_ptr(&timer_bases[b], cpu); + base->clk = jiffies; + base->next_expiry = base->clk + NEXT_TIMER_MAX_DELTA; + base->is_idle = false; + base->must_forward_clk = true; + } + return 0; +} + int timers_dead_cpu(unsigned int cpu) { struct timer_base *old_base; |