clockevents: do not shutdown the oneshot broadcast device

When a cpu goes offline it is removed from the broadcast masks. If the mask becomes empty the code shuts down the broadcast device. This is wrong, because the broadcast device needs to be ready for the online cpu going idle (into a c-state, which stops the local apic timer). Signed-off-by: Thomas Gleixner <[email protected]>
kyagi · Sep 16, 2007 · 31d9b39 · 31d9b39
1 parent 07eec6a
commit 31d9b39
Showing 1 changed file with 4 additions and 7 deletions.
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
@@ -560,20 +560,17 @@ void tick_broadcast_switch_to_oneshot(void)
  */
 void tick_shutdown_broadcast_oneshot(unsigned int *cpup)
 {
-	struct clock_event_device *bc;
 	unsigned long flags;
 	unsigned int cpu = *cpup;
 
 	spin_lock_irqsave(&tick_broadcast_lock, flags);
 
-	bc = tick_broadcast_device.evtdev;
+	/*
+	 * Clear the broadcast mask flag for the dead cpu, but do not
+	 * stop the broadcast device!
+	 */
 	cpu_clear(cpu, tick_broadcast_oneshot_mask);
 
-	if (tick_broadcast_device.mode == TICKDEV_MODE_ONESHOT) {
-		if (bc && cpus_empty(tick_broadcast_oneshot_mask))
-			clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
-	}
-
 	spin_unlock_irqrestore(&tick_broadcast_lock, flags);
 }