1 files changed, 39 insertions, 4 deletions

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 1972b161c61e..94bbe4695232 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -20,6 +20,7 @@
 #include <linux/gfp.h>
 #include <linux/suspend.h>
 #include <linux/lockdep.h>
+#include <linux/tick.h>
 #include <trace/events/power.h>
 
 #include "smpboot.h"
@@ -338,6 +339,8 @@ static int __ref take_cpu_down(void *_param)
                 return err;
 
         cpu_notify(CPU_DYING | param->mod, param->hcpu);
+        /* Give up timekeeping duties */
+        tick_handover_do_timer();
         /* Park the stopper thread */
         kthread_park(current);
         return 0;
@@ -408,13 +411,17 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
          *
          * Wait for the stop thread to go away.
          */
-        while (!idle_cpu(cpu))
+        while (!per_cpu(cpu_dead_idle, cpu))
                 cpu_relax();
+        smp_mb(); /* Read from cpu_dead_idle before __cpu_die(). */
+        per_cpu(cpu_dead_idle, cpu) = false;
 
+        hotplug_cpu__broadcast_tick_pull(cpu);
         /* This actually kills the CPU. */
         __cpu_die(cpu);
 
         /* CPU is completely dead: tell everyone.  Too late to complain. */
+        tick_cleanup_dead_cpu(cpu);
         cpu_notify_nofail(CPU_DEAD | mod, hcpu);
 
         check_for_tasks(cpu);
@@ -446,6 +453,37 @@ out:
 EXPORT_SYMBOL(cpu_down);
 #endif /*CONFIG_HOTPLUG_CPU*/
 
+/*
+ * Unpark per-CPU smpboot kthreads at CPU-online time.
+ */
+static int smpboot_thread_call(struct notifier_block *nfb,
+                               unsigned long action, void *hcpu)
+{
+        int cpu = (long)hcpu;
+
+        switch (action & ~CPU_TASKS_FROZEN) {
+
+        case CPU_ONLINE:
+                smpboot_unpark_threads(cpu);
+                break;
+
+        default:
+                break;
+        }
+
+        return NOTIFY_OK;
+}
+
+static struct notifier_block smpboot_thread_notifier = {
+        .notifier_call = smpboot_thread_call,
+        .priority = CPU_PRI_SMPBOOT,
+};
+
+void __cpuinit smpboot_thread_init(void)
+{
+        register_cpu_notifier(&smpboot_thread_notifier);
+}
+
 /* Requires cpu_add_remove_lock to be held */
 static int _cpu_up(unsigned int cpu, int tasks_frozen)
 {
@@ -485,9 +523,6 @@ static int _cpu_up(unsigned int cpu, int tasks_frozen)
                 goto out_notify;
         BUG_ON(!cpu_online(cpu));
 
-        /* Wake the per cpu threads */
-        smpboot_unpark_threads(cpu);
-
         /* Now call notifier in preparation. */
         cpu_notify(CPU_ONLINE | mod, hcpu);