clockevents: check broadcast tick device not the clock events device

Impact: jiffies increment too fast.

Hugh Dickins noted that with NOHZ=n and HIGHRES=n jiffies get
incremented too fast. The reason is a wrong check in the broadcast
enter/exit code, which keeps the local apic timer in periodic mode
when the switch happens.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index bd70345..cb01cd8 100644 (file)
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -235,7 +235,8 @@ static void tick_do_broadcast_on_off(void *why)
        case CLOCK_EVT_NOTIFY_BROADCAST_FORCE:
                if (!cpu_isset(cpu, tick_broadcast_mask)) {
                        cpu_set(cpu, tick_broadcast_mask);
-                       if (bc->mode == TICKDEV_MODE_PERIODIC)
+                       if (tick_broadcast_device.mode ==
+                           TICKDEV_MODE_PERIODIC)
                                clockevents_shutdown(dev);
                }
                if (*reason == CLOCK_EVT_NOTIFY_BROADCAST_FORCE)
@@ -245,7 +246,8 @@ static void tick_do_broadcast_on_off(void *why)
                if (!tick_broadcast_force &&
                    cpu_isset(cpu, tick_broadcast_mask)) {
                        cpu_clear(cpu, tick_broadcast_mask);
-                       if (bc->mode == TICKDEV_MODE_PERIODIC)
+                       if (tick_broadcast_device.mode ==
+                           TICKDEV_MODE_PERIODIC)
                                tick_setup_periodic(dev, 0);
                }
                break;