diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h index c1e85550bf12..9f0f91dc8d7d 100644 --- a/include/linux/kernel_stat.h +++ b/include/linux/kernel_stat.h @@ -40,6 +40,9 @@ struct kernel_cpustat { seqcount_t idle_sleeptime_seq; u64 idle_entrytime; u64 idle_stealtime[2]; + u64 idle_dyntick_entry; + u64 idle_tick_period; + u64 idle_tick_overlap; #endif u64 cpustat[NR_STATS]; }; @@ -111,7 +114,7 @@ static inline unsigned long kstat_cpu_irqs_sum(unsigned int cpu) #ifdef CONFIG_HAVE_VIRT_CPU_ACCOUNTING_IDLE static inline void kcpustat_dyntick_start(u64 now) { } -static inline void kcpustat_dyntick_stop(u64 now) { } +static inline void kcpustat_dyntick_stop(u64 now, u64 tick_start) { } static inline void kcpustat_irq_enter(u64 now) { } static inline void kcpustat_irq_exit(u64 now) { } static inline bool kcpustat_idle_dyntick(void) { return false; } @@ -132,7 +135,7 @@ static inline u64 kcpustat_field_iowait(int cpu) #else /* !CONFIG_HAVE_VIRT_CPU_ACCOUNTING_IDLE */ extern void kcpustat_dyntick_start(u64 now); -extern void kcpustat_dyntick_stop(u64 now); +extern void kcpustat_dyntick_stop(u64 now, u64 tick_start); extern void kcpustat_irq_enter(u64 now); extern void kcpustat_irq_exit(u64 now); extern u64 kcpustat_field_idle(int cpu); diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index f16970ca81d0..19aa804c2589 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -381,9 +381,9 @@ void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times) * softirq as those do not count in task exec_runtime any more. */ static void irqtime_account_process_tick(struct task_struct *p, int user_tick, - int ticks) + u64 cputime) { - u64 other, cputime = TICK_NSEC * ticks; + u64 other; /* * When returning from idle, many ticks can get accounted at @@ -418,7 +418,7 @@ static void irqtime_account_process_tick(struct task_struct *p, int user_tick, #else /* !CONFIG_IRQ_TIME_ACCOUNTING: */ static inline void irqtime_account_process_tick(struct task_struct *p, int user_tick, - int nr_ticks) { } + u64 cputime) { } #endif /* !CONFIG_IRQ_TIME_ACCOUNTING */ #if defined(CONFIG_NO_HZ_COMMON) && !defined(CONFIG_HAVE_VIRT_CPU_ACCOUNTING_IDLE) @@ -468,18 +468,38 @@ static void kcpustat_idle_start(struct kernel_cpustat *kc, u64 now) write_seqcount_end(&kc->idle_sleeptime_seq); } -void kcpustat_dyntick_stop(u64 now) +void kcpustat_dyntick_stop(u64 now, u64 tick_start) { struct kernel_cpustat *kc = kcpustat_this_cpu; if (!vtime_generic_enabled_this_cpu()) { WARN_ON_ONCE(!kc->idle_dyntick); + if (kc->idle_tick_period != tick_start) { + kc->idle_tick_period = tick_start; + kc->idle_tick_overlap = 0; + } + tick_start = max(tick_start, kc->idle_dyntick_entry); + if (!WARN_ON_ONCE(now < tick_start)) + kc->idle_tick_overlap += now - tick_start; kcpustat_idle_stop(kc, now); kc->idle_dyntick = false; vtime_dyntick_stop(); } } +/* + * The first tick after dyntick-idle covers a period that the dyntick-idle + * accounting may already have accounted in part. + */ +static inline u64 kcpustat_tick_overlap(void) +{ + struct kernel_cpustat *kc = kcpustat_this_cpu; + u64 overlap = kc->idle_tick_overlap; + + kc->idle_tick_overlap = 0; + return overlap; +} + void kcpustat_dyntick_start(u64 now) { struct kernel_cpustat *kc = kcpustat_this_cpu; @@ -487,6 +507,7 @@ void kcpustat_dyntick_start(u64 now) if (!vtime_generic_enabled_this_cpu()) { vtime_dyntick_start(); kc->idle_dyntick = true; + kc->idle_dyntick_entry = now; kcpustat_idle_start(kc, now); } } @@ -555,6 +576,11 @@ u64 kcpustat_field_iowait(int cpu) } EXPORT_SYMBOL_GPL(kcpustat_field_iowait); #else +static inline u64 kcpustat_tick_overlap(void) +{ + return 0; +} + static u64 kcpustat_field_dyntick(int cpu, enum cpu_usage_stat idx, bool compute_delta, ktime_t now) { @@ -695,12 +721,13 @@ void account_process_tick(struct task_struct *p, int user_tick) if (kcpustat_idle_dyntick()) return; + cputime = TICK_NSEC - kcpustat_tick_overlap(); + if (irqtime_enabled()) { - irqtime_account_process_tick(p, user_tick, 1); + irqtime_account_process_tick(p, user_tick, cputime); return; } - cputime = TICK_NSEC; steal = steal_account_process_time(ULONG_MAX); if (steal >= cputime) diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 6c3fea386713..4e293f81e4dc 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -763,12 +763,18 @@ static ktime_t tick_forward_now(ktime_t expires, ktime_t now) return expires + TICK_NSEC; } +static void tick_nohz_forward_last_tick(struct tick_sched *ts, ktime_t now) +{ + if (now >= ts->last_tick) + ts->last_tick = tick_forward_now(ts->last_tick, now); +} + static void tick_nohz_restart(struct tick_sched *ts, ktime_t now) { - ktime_t expires = ts->last_tick; + ktime_t expires; - if (now >= expires) - expires = tick_forward_now(expires, now); + tick_nohz_forward_last_tick(ts, now); + expires = ts->last_tick; if (tick_sched_flag_test(ts, TS_FLAG_HIGHRES)) { hrtimer_start(&ts->sched_timer, expires, HRTIMER_MODE_ABS_PINNED_HARD); @@ -1329,6 +1335,12 @@ unsigned long tick_nohz_get_idle_calls_cpu(int cpu) return ts->idle_calls; } +static void tick_nohz_dyntick_stop(struct tick_sched *ts, ktime_t now) +{ + tick_nohz_forward_last_tick(ts, now); + kcpustat_dyntick_stop(now, ts->last_tick - TICK_NSEC); +} + void tick_nohz_idle_restart_tick(void) { struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched); @@ -1341,7 +1353,7 @@ void tick_nohz_idle_restart_tick(void) * no tiny amount of idle time is accounted twice. */ ts->idle_entrytime = ktime_get(); - kcpustat_dyntick_stop(ts->idle_entrytime); + tick_nohz_dyntick_stop(ts, ts->idle_entrytime); tick_nohz_restart_sched_tick(ts, ts->idle_entrytime); } } @@ -1385,7 +1397,7 @@ void tick_nohz_idle_exit(void) if (tick_sched_flag_test(ts, TS_FLAG_STOPPED)) { now = ktime_get(); - kcpustat_dyntick_stop(now); + tick_nohz_dyntick_stop(ts, now); tick_nohz_idle_update_tick(ts, now); }