Force tick interrupt and get rid of softirq magic

[kvmfornfv.git] / kernel / kernel / time / tick-sched.c

diff --git a/kernel/kernel/time/tick-sched.c b/kernel/kernel/time/tick-sched.c
index b3841ba..f61dbf2 100644 (file)
--- a/kernel/kernel/time/tick-sched.c
+++ b/kernel/kernel/time/tick-sched.c
@@ -576,6 +576,20 @@ u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time)
 }
 EXPORT_SYMBOL_GPL(get_cpu_iowait_time_us);
 
+static void tick_nohz_restart(struct tick_sched *ts, ktime_t now)
+{
+        hrtimer_cancel(&ts->sched_timer);
+        hrtimer_set_expires(&ts->sched_timer, ts->last_tick);
+
+        /* Forward the time to expire in the future */
+        hrtimer_forward(&ts->sched_timer, now, tick_period);
+
+        if (ts->nohz_mode == NOHZ_MODE_HIGHRES)
+                hrtimer_start_expires(&ts->sched_timer, HRTIMER_MODE_ABS_PINNED);
+        else
+                tick_program_event(hrtimer_get_expires(&ts->sched_timer), 1);
+}
+
 static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
                                         ktime_t now, int cpu)
 {
@@ -704,22 +718,16 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
                        goto out;
                }
 
-               if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
-                       hrtimer_start(&ts->sched_timer, expires,
-                                     HRTIMER_MODE_ABS_PINNED);
-                       /* Check, if the timer was already in the past */
-                       if (hrtimer_active(&ts->sched_timer))
-                               goto out;
-               } else if (!tick_program_event(expires, 0))
-                               goto out;
-               /*
-                * We are past the event already. So we crossed a
-                * jiffie boundary. Update jiffies and raise the
-                * softirq.
-                */
-               tick_do_update_jiffies64(ktime_get());
+                if (ts->nohz_mode == NOHZ_MODE_HIGHRES)
+                        hrtimer_start(&ts->sched_timer, expires,
+                                      HRTIMER_MODE_ABS_PINNED);
+                else
+                        tick_program_event(expires, 1);
+       } else {
+               /* Tick is stopped, but required now. Enforce it */
+               tick_nohz_restart(ts, now);
+
        }
-       raise_softirq_irqoff(TIMER_SOFTIRQ);
 out:
        ts->next_jiffies = next_jiffies;
        ts->last_jiffies = last_jiffies;
@@ -880,32 +888,6 @@ ktime_t tick_nohz_get_sleep_length(void)
        return ts->sleep_length;
 }
 
-static void tick_nohz_restart(struct tick_sched *ts, ktime_t now)
-{
-       hrtimer_cancel(&ts->sched_timer);
-       hrtimer_set_expires(&ts->sched_timer, ts->last_tick);
-
-       while (1) {
-               /* Forward the time to expire in the future */
-               hrtimer_forward(&ts->sched_timer, now, tick_period);
-
-               if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
-                       hrtimer_start_expires(&ts->sched_timer,
-                                             HRTIMER_MODE_ABS_PINNED);
-                       /* Check, if the timer was already in the past */
-                       if (hrtimer_active(&ts->sched_timer))
-                               break;
-               } else {
-                       if (!tick_program_event(
-                               hrtimer_get_expires(&ts->sched_timer), 0))
-                               break;
-               }
-               /* Reread time and update jiffies */
-               now = ktime_get();
-               tick_do_update_jiffies64(now);
-       }
-}
-
 static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now)
 {
        /* Update jiffies first */