diff options
Diffstat (limited to 'kernel/time/tick-sched.c')
| -rw-r--r-- | kernel/time/tick-sched.c | 70 |
1 files changed, 40 insertions, 30 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 5bbb1044f84..1b6c05bd0d0 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -144,7 +144,7 @@ void tick_nohz_update_jiffies(void) if (!ts->tick_stopped) return; - cpu_clear(cpu, nohz_cpu_mask); + cpumask_clear_cpu(cpu, nohz_cpu_mask); now = ktime_get(); ts->idle_waketime = now; @@ -247,7 +247,7 @@ void tick_nohz_stop_sched_tick(int inidle) if (need_resched()) goto end; - if (unlikely(local_softirq_pending())) { + if (unlikely(local_softirq_pending() && cpu_online(cpu))) { static int ratelimit; if (ratelimit < 10) { @@ -282,8 +282,31 @@ void tick_nohz_stop_sched_tick(int inidle) /* Schedule the tick, if we are at least one jiffie off */ if ((long)delta_jiffies >= 1) { + /* + * calculate the expiry time for the next timer wheel + * timer + */ + expires = ktime_add_ns(last_update, tick_period.tv64 * + delta_jiffies); + + /* + * If this cpu is the one which updates jiffies, then + * give up the assignment and let it be taken by the + * cpu which runs the tick timer next, which might be + * this cpu as well. If we don't drop this here the + * jiffies might be stale and do_timer() never + * invoked. + */ + if (cpu == tick_do_timer_cpu) + tick_do_timer_cpu = TICK_DO_TIMER_NONE; + if (delta_jiffies > 1) - cpu_set(cpu, nohz_cpu_mask); + cpumask_set_cpu(cpu, nohz_cpu_mask); + + /* Skip reprogram of event if its not changed */ + if (ts->tick_stopped && ktime_equal(expires, dev->next_event)) + goto out; + /* * nohz_stop_sched_tick can be called several times before * the nohz_restart_sched_tick is called. This happens when @@ -296,7 +319,7 @@ void tick_nohz_stop_sched_tick(int inidle) /* * sched tick not stopped! */ - cpu_clear(cpu, nohz_cpu_mask); + cpumask_clear_cpu(cpu, nohz_cpu_mask); goto out; } @@ -306,17 +329,6 @@ void tick_nohz_stop_sched_tick(int inidle) rcu_enter_nohz(); } - /* - * If this cpu is the one which updates jiffies, then - * give up the assignment and let it be taken by the - * cpu which runs the tick timer next, which might be - * this cpu as well. If we don't drop this here the - * jiffies might be stale and do_timer() never - * invoked. - */ - if (cpu == tick_do_timer_cpu) - tick_do_timer_cpu = TICK_DO_TIMER_NONE; - ts->idle_sleeps++; /* @@ -332,12 +344,7 @@ void tick_nohz_stop_sched_tick(int inidle) goto out; } - /* - * calculate the expiry time for the next timer wheel - * timer - */ - expires = ktime_add_ns(last_update, tick_period.tv64 * - delta_jiffies); + /* Mark expiries */ ts->idle_expires = expires; if (ts->nohz_mode == NOHZ_MODE_HIGHRES) { @@ -354,7 +361,7 @@ void tick_nohz_stop_sched_tick(int inidle) * softirq. */ tick_do_update_jiffies64(ktime_get()); - cpu_clear(cpu, nohz_cpu_mask); + cpumask_clear_cpu(cpu, nohz_cpu_mask); } raise_softirq_irqoff(TIMER_SOFTIRQ); out: @@ -412,7 +419,9 @@ void tick_nohz_restart_sched_tick(void) { int cpu = smp_processor_id(); struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); +#ifndef CONFIG_VIRT_CPU_ACCOUNTING unsigned long ticks; +#endif ktime_t now; local_irq_disable(); @@ -432,8 +441,9 @@ void tick_nohz_restart_sched_tick(void) select_nohz_load_balancer(0); now = ktime_get(); tick_do_update_jiffies64(now); - cpu_clear(cpu, nohz_cpu_mask); + cpumask_clear_cpu(cpu, nohz_cpu_mask); +#ifndef CONFIG_VIRT_CPU_ACCOUNTING /* * We stopped the tick in idle. Update process times would miss the * time we slept as update_process_times does only a 1 tick @@ -443,12 +453,9 @@ void tick_nohz_restart_sched_tick(void) /* * We might be one off. Do not randomly account a huge number of ticks! */ - if (ticks && ticks < LONG_MAX) { - add_preempt_count(HARDIRQ_OFFSET); - account_system_time(current, HARDIRQ_OFFSET, - jiffies_to_cputime(ticks)); - sub_preempt_count(HARDIRQ_OFFSET); - } + if (ticks && ticks < LONG_MAX) + account_idle_ticks(ticks); +#endif touch_softlockup_watchdog(); /* @@ -568,6 +575,9 @@ static void tick_nohz_switch_to_nohz(void) */ static void tick_nohz_kick_tick(int cpu) { +#if 0 + /* Switch back to 2.6.27 behaviour */ + struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); ktime_t delta, now; @@ -584,6 +594,7 @@ static void tick_nohz_kick_tick(int cpu) return; tick_nohz_restart(ts, now); +#endif } #else @@ -677,7 +688,6 @@ void tick_setup_sched_timer(void) */ hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); ts->sched_timer.function = tick_sched_timer; - ts->sched_timer.cb_mode = HRTIMER_CB_IRQSAFE_PERCPU; /* Get the next period (per cpu) */ hrtimer_set_expires(&ts->sched_timer, tick_init_jiffy_update()); |