sched: Make hrtick_notifier an explicit call

No need for an extra notifier. We don't need to handle all these states. It's
sufficient to kill the timer when the cpu dies.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160310120025.770528462@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 28ffd68..9c710ad 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -249,29 +249,6 @@ void hrtick_start(struct rq *rq, u64 delay)
        }
 }
 
-static int
-hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu)
-{
-       int cpu = (int)(long)hcpu;
-
-       switch (action) {
-       case CPU_UP_CANCELED:
-       case CPU_UP_CANCELED_FROZEN:
-       case CPU_DOWN_PREPARE:
-       case CPU_DOWN_PREPARE_FROZEN:
-       case CPU_DEAD:
-       case CPU_DEAD_FROZEN:
-               hrtick_clear(cpu_rq(cpu));
-               return NOTIFY_OK;
-       }
-
-       return NOTIFY_DONE;
-}
-
-static __init void init_hrtick(void)
-{
-       hotcpu_notifier(hotplug_hrtick, 0);
-}
 #else
 /*
  * Called to set the hrtick timer state.
@@ -288,10 +265,6 @@ void hrtick_start(struct rq *rq, u64 delay)
        hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay),
                      HRTIMER_MODE_REL_PINNED);
 }
-
-static inline void init_hrtick(void)
-{
-}
 #endif /* CONFIG_SMP */
 
 static void init_rq_hrtick(struct rq *rq)
@@ -315,10 +288,6 @@ static inline void hrtick_clear(struct rq *rq)
 static inline void init_rq_hrtick(struct rq *rq)
 {
 }
-
-static inline void init_hrtick(void)
-{
-}
 #endif /* CONFIG_SCHED_HRTICK */
 
 /*
@@ -7132,6 +7101,7 @@ int sched_cpu_dying(unsigned int cpu)
        calc_load_migrate(rq);
        update_max_interval();
        nohz_balance_exit_idle(cpu);
+       hrtick_clear(rq);
        return 0;
 }
 #endif
@@ -7157,8 +7127,6 @@ void __init sched_init_smp(void)
                cpumask_set_cpu(smp_processor_id(), non_isolated_cpus);
        mutex_unlock(&sched_domains_mutex);
 
-       init_hrtick();
-
        /* Move init over to a non-isolated CPU */
        if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0)
                BUG();