Merge branches 'release', 'asus', 'bugzilla-12450', 'cpuidle', 'debug', 'ec', 'misc...

[safe/jmp/linux-2.6] / kernel / time / tick-sched.c

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 342fc9c..d3f1ef4 100644 (file)
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -134,7 +134,7 @@ __setup("nohz=", setup_tick_nohz);
  * value. We do this unconditionally on any cpu, as we don't know whether the
  * cpu, which has the update task assigned is in a long sleep.
  */
-void tick_nohz_update_jiffies(void)
+static void tick_nohz_update_jiffies(void)
 {
        int cpu = smp_processor_id();
        struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
@@ -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();
        /*
@@ -681,7 +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());