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Diffstat (limited to 'kernel/time/tick-sched.c')
-rw-r--r--kernel/time/tick-sched.c86
1 files changed, 40 insertions, 46 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 3612fc77f834..9f8af69c67ec 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -86,6 +86,7 @@ static void tick_do_update_jiffies64(ktime_t now)
tick_next_period = ktime_add(last_jiffies_update, tick_period);
}
write_sequnlock(&jiffies_lock);
+ update_wall_time();
}
/*
@@ -177,7 +178,7 @@ static bool can_stop_full_tick(void)
* TODO: kick full dynticks CPUs when
* sched_clock_stable is set.
*/
- if (!sched_clock_stable) {
+ if (!sched_clock_stable()) {
trace_tick_stop(0, "unstable sched clock\n");
/*
* Don't allow the user to think they can get
@@ -361,8 +362,8 @@ void __init tick_nohz_init(void)
/*
* NO HZ enabled ?
*/
-int tick_nohz_enabled __read_mostly = 1;
-
+static int tick_nohz_enabled __read_mostly = 1;
+int tick_nohz_active __read_mostly;
/*
* Enable / Disable tickless mode
*/
@@ -391,11 +392,9 @@ __setup("nohz=", setup_tick_nohz);
*/
static void tick_nohz_update_jiffies(ktime_t now)
{
- int cpu = smp_processor_id();
- struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
unsigned long flags;
- ts->idle_waketime = now;
+ __this_cpu_write(tick_cpu_sched.idle_waketime, now);
local_irq_save(flags);
tick_do_update_jiffies64(now);
@@ -426,17 +425,15 @@ update_ts_time_stats(int cpu, struct tick_sched *ts, ktime_t now, u64 *last_upda
}
-static void tick_nohz_stop_idle(int cpu, ktime_t now)
+static void tick_nohz_stop_idle(struct tick_sched *ts, ktime_t now)
{
- struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
-
- update_ts_time_stats(cpu, ts, now, NULL);
+ update_ts_time_stats(smp_processor_id(), ts, now, NULL);
ts->idle_active = 0;
sched_clock_idle_wakeup_event(0);
}
-static ktime_t tick_nohz_start_idle(int cpu, struct tick_sched *ts)
+static ktime_t tick_nohz_start_idle(struct tick_sched *ts)
{
ktime_t now = ktime_get();
@@ -465,7 +462,7 @@ u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time)
struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
ktime_t now, idle;
- if (!tick_nohz_enabled)
+ if (!tick_nohz_active)
return -1;
now = ktime_get();
@@ -506,7 +503,7 @@ u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time)
struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
ktime_t now, iowait;
- if (!tick_nohz_enabled)
+ if (!tick_nohz_active)
return -1;
now = ktime_get();
@@ -536,12 +533,13 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
u64 time_delta;
+ time_delta = timekeeping_max_deferment();
+
/* Read jiffies and the time when jiffies were updated last */
do {
seq = read_seqbegin(&jiffies_lock);
last_update = last_jiffies_update;
last_jiffies = jiffies;
- time_delta = timekeeping_max_deferment();
} while (read_seqretry(&jiffies_lock, seq));
if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) ||
@@ -681,18 +679,18 @@ out:
static void tick_nohz_full_stop_tick(struct tick_sched *ts)
{
#ifdef CONFIG_NO_HZ_FULL
- int cpu = smp_processor_id();
+ int cpu = smp_processor_id();
- if (!tick_nohz_full_cpu(cpu) || is_idle_task(current))
- return;
+ if (!tick_nohz_full_cpu(cpu) || is_idle_task(current))
+ return;
- if (!ts->tick_stopped && ts->nohz_mode == NOHZ_MODE_INACTIVE)
- return;
+ if (!ts->tick_stopped && ts->nohz_mode == NOHZ_MODE_INACTIVE)
+ return;
- if (!can_stop_full_tick())
- return;
+ if (!can_stop_full_tick())
+ return;
- tick_nohz_stop_sched_tick(ts, ktime_get(), cpu);
+ tick_nohz_stop_sched_tick(ts, ktime_get(), cpu);
#endif
}
@@ -711,8 +709,10 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts)
return false;
}
- if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE))
+ if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE)) {
+ ts->sleep_length = (ktime_t) { .tv64 = NSEC_PER_SEC/HZ };
return false;
+ }
if (need_resched())
return false;
@@ -752,7 +752,7 @@ static void __tick_nohz_idle_enter(struct tick_sched *ts)
ktime_t now, expires;
int cpu = smp_processor_id();
- now = tick_nohz_start_idle(cpu, ts);
+ now = tick_nohz_start_idle(ts);
if (can_stop_idle_tick(cpu, ts)) {
int was_stopped = ts->tick_stopped;
@@ -799,11 +799,6 @@ void tick_nohz_idle_enter(void)
local_irq_disable();
ts = &__get_cpu_var(tick_cpu_sched);
- /*
- * set ts->inidle unconditionally. even if the system did not
- * switch to nohz mode the cpu frequency governers rely on the
- * update of the idle time accounting in tick_nohz_start_idle().
- */
ts->inidle = 1;
__tick_nohz_idle_enter(ts);
@@ -914,8 +909,7 @@ static void tick_nohz_account_idle_ticks(struct tick_sched *ts)
*/
void tick_nohz_idle_exit(void)
{
- int cpu = smp_processor_id();
- struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
+ struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
ktime_t now;
local_irq_disable();
@@ -928,7 +922,7 @@ void tick_nohz_idle_exit(void)
now = ktime_get();
if (ts->idle_active)
- tick_nohz_stop_idle(cpu, now);
+ tick_nohz_stop_idle(ts, now);
if (ts->tick_stopped) {
tick_nohz_restart_sched_tick(ts, now);
@@ -973,7 +967,7 @@ static void tick_nohz_switch_to_nohz(void)
struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
ktime_t next;
- if (!tick_nohz_enabled)
+ if (!tick_nohz_active)
return;
local_irq_disable();
@@ -981,7 +975,7 @@ static void tick_nohz_switch_to_nohz(void)
local_irq_enable();
return;
}
-
+ tick_nohz_active = 1;
ts->nohz_mode = NOHZ_MODE_LOWRES;
/*
@@ -1012,12 +1006,10 @@ static void tick_nohz_switch_to_nohz(void)
* timer and do not touch the other magic bits which need to be done
* when idle is left.
*/
-static void tick_nohz_kick_tick(int cpu, ktime_t now)
+static void tick_nohz_kick_tick(struct tick_sched *ts, ktime_t now)
{
#if 0
/* Switch back to 2.6.27 behaviour */
-
- struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
ktime_t delta;
/*
@@ -1032,36 +1024,36 @@ static void tick_nohz_kick_tick(int cpu, ktime_t now)
#endif
}
-static inline void tick_check_nohz(int cpu)
+static inline void tick_nohz_irq_enter(void)
{
- struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
+ struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
ktime_t now;
if (!ts->idle_active && !ts->tick_stopped)
return;
now = ktime_get();
if (ts->idle_active)
- tick_nohz_stop_idle(cpu, now);
+ tick_nohz_stop_idle(ts, now);
if (ts->tick_stopped) {
tick_nohz_update_jiffies(now);
- tick_nohz_kick_tick(cpu, now);
+ tick_nohz_kick_tick(ts, now);
}
}
#else
static inline void tick_nohz_switch_to_nohz(void) { }
-static inline void tick_check_nohz(int cpu) { }
+static inline void tick_nohz_irq_enter(void) { }
#endif /* CONFIG_NO_HZ_COMMON */
/*
* Called from irq_enter to notify about the possible interruption of idle()
*/
-void tick_check_idle(int cpu)
+void tick_irq_enter(void)
{
- tick_check_oneshot_broadcast(cpu);
- tick_check_nohz(cpu);
+ tick_check_oneshot_broadcast_this_cpu();
+ tick_nohz_irq_enter();
}
/*
@@ -1139,8 +1131,10 @@ void tick_setup_sched_timer(void)
}
#ifdef CONFIG_NO_HZ_COMMON
- if (tick_nohz_enabled)
+ if (tick_nohz_enabled) {
ts->nohz_mode = NOHZ_MODE_HIGHRES;
+ tick_nohz_active = 1;
+ }
#endif
}
#endif /* HIGH_RES_TIMERS */