X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Ftime%2Ftick-sched.c;h=686da821d376b01dd21d379bfd8baf39d6b106f1;hb=b4de123a0bc4a3f0c90899864d51299628729952;hp=1a21b6fdb674b878d566789bac2c799da7593adf;hpb=2d44ae4d7135b9aee26439b3523b43473381bc5f;p=linux-2.6

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 1a21b6fdb6..686da821d3 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -9,7 +9,7 @@
  *
  *  Started by: Thomas Gleixner and Ingo Molnar
  *
- *  For licencing details see kernel-base/COPYING
+ *  Distribute under GPLv2.
  */
 #include <linux/cpu.h>
 #include <linux/err.h>
@@ -137,12 +137,51 @@ void tick_nohz_update_jiffies(void)
 
 	cpu_clear(cpu, nohz_cpu_mask);
 	now = ktime_get();
+	ts->idle_waketime = now;
 
 	local_irq_save(flags);
 	tick_do_update_jiffies64(now);
 	local_irq_restore(flags);
 }
 
+void tick_nohz_stop_idle(int cpu)
+{
+	struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
+
+	if (ts->idle_active) {
+		ktime_t now, delta;
+		now = ktime_get();
+		delta = ktime_sub(now, ts->idle_entrytime);
+		ts->idle_lastupdate = now;
+		ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
+		ts->idle_active = 0;
+	}
+}
+
+static ktime_t tick_nohz_start_idle(int cpu)
+{
+	struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
+	ktime_t now, delta;
+
+	now = ktime_get();
+	if (ts->idle_active) {
+		delta = ktime_sub(now, ts->idle_entrytime);
+		ts->idle_lastupdate = now;
+		ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
+	}
+	ts->idle_entrytime = now;
+	ts->idle_active = 1;
+	return now;
+}
+
+u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time)
+{
+	struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
+
+	*last_update_time = ktime_to_us(ts->idle_lastupdate);
+	return ktime_to_us(ts->idle_sleeptime);
+}
+
 /**
  * tick_nohz_stop_sched_tick - stop the idle tick from the idle task
  *
@@ -155,13 +194,14 @@ void tick_nohz_stop_sched_tick(void)
 	unsigned long seq, last_jiffies, next_jiffies, delta_jiffies, flags;
 	unsigned long rt_jiffies;
 	struct tick_sched *ts;
-	ktime_t last_update, expires, now, delta;
+	ktime_t last_update, expires, now;
 	struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
 	int cpu;
 
 	local_irq_save(flags);
 
 	cpu = smp_processor_id();
+	now = tick_nohz_start_idle(cpu);
 	ts = &per_cpu(tick_cpu_sched, cpu);
 
 	/*
@@ -193,19 +233,7 @@ void tick_nohz_stop_sched_tick(void)
 		}
 	}
 
-	now = ktime_get();
-	/*
-	 * When called from irq_exit we need to account the idle sleep time
-	 * correctly.
-	 */
-	if (ts->tick_stopped) {
-		delta = ktime_sub(now, ts->idle_entrytime);
-		ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
-	}
-
-	ts->idle_entrytime = now;
 	ts->idle_calls++;
-
 	/* Read jiffies and the time when jiffies were updated last */
 	do {
 		seq = read_seqbegin(&xtime_lock);
@@ -254,6 +282,7 @@ void tick_nohz_stop_sched_tick(void)
 			ts->idle_tick = ts->sched_timer.expires;
 			ts->tick_stopped = 1;
 			ts->idle_jiffies = last_jiffies;
+			rcu_enter_nohz();
 		}
 
 		/*
@@ -296,7 +325,7 @@ void tick_nohz_stop_sched_tick(void)
 			/* Check, if the timer was already in the past */
 			if (hrtimer_active(&ts->sched_timer))
 				goto out;
-		} else if(!tick_program_event(expires, 0))
+		} else if (!tick_program_event(expires, 0))
 				goto out;
 		/*
 		 * We are past the event already. So we crossed a
@@ -337,23 +366,24 @@ void tick_nohz_restart_sched_tick(void)
 	int cpu = smp_processor_id();
 	struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
 	unsigned long ticks;
-	ktime_t now, delta;
+	ktime_t now;
 
-	if (!ts->tick_stopped)
+	local_irq_disable();
+	tick_nohz_stop_idle(cpu);
+
+	if (!ts->tick_stopped) {
+		local_irq_enable();
 		return;
+	}
 
-	/* Update jiffies first */
-	now = ktime_get();
+	rcu_exit_nohz();
 
-	local_irq_disable();
+	/* Update jiffies first */
 	select_nohz_load_balancer(0);
+	now = ktime_get();
 	tick_do_update_jiffies64(now);
 	cpu_clear(cpu, nohz_cpu_mask);
 
-	/* Account the idle time */
-	delta = ktime_sub(now, ts->idle_entrytime);
-	ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
-
 	/*
 	 * We stopped the tick in idle. Update process times would miss the
 	 * time we slept as update_process_times does only a 1 tick
@@ -374,6 +404,7 @@ void tick_nohz_restart_sched_tick(void)
 	 * Cancel the scheduled timer and restore the tick
 	 */
 	ts->tick_stopped  = 0;
+	ts->idle_exittime = now;
 	hrtimer_cancel(&ts->sched_timer);
 	ts->sched_timer.expires = ts->idle_tick;
 
@@ -507,7 +538,7 @@ static inline void tick_nohz_switch_to_nohz(void) { }
  */
 #ifdef CONFIG_HIGH_RES_TIMERS
 /*
- * We rearm the timer until we get disabled by the idle code
+ * We rearm the timer until we get disabled by the idle code.
  * Called with interrupts disabled and timer->base->cpu_base->lock held.
  */
 static enum hrtimer_restart tick_sched_timer(struct hrtimer *timer)
@@ -609,7 +640,7 @@ void tick_cancel_sched_timer(int cpu)
 
 	if (ts->sched_timer.base)
 		hrtimer_cancel(&ts->sched_timer);
-	ts->tick_stopped = 0;
+
 	ts->nohz_mode = NOHZ_MODE_INACTIVE;
 }
 #endif /* HIGH_RES_TIMERS */
@@ -653,7 +684,7 @@ int tick_check_oneshot_change(int allow_nohz)
 	if (ts->nohz_mode != NOHZ_MODE_INACTIVE)
 		return 0;
 
-	if (!timekeeping_is_continuous() || !tick_is_oneshot_available())
+	if (!timekeeping_valid_for_hres() || !tick_is_oneshot_available())
 		return 0;
 
 	if (!allow_nohz)