1 files changed, 6 insertions, 10 deletions

diff --git a/kernel/cpu.c b/kernel/cpu.c
index f6e726f18491..8615aa65d927 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -189,7 +189,6 @@ static inline void check_for_tasks(int cpu)
 }
 
 struct take_cpu_down_param {
-        struct task_struct *caller;
         unsigned long mod;
         void *hcpu;
 };
@@ -208,11 +207,6 @@ static int __ref take_cpu_down(void *_param)
 
         cpu_notify(CPU_DYING | param->mod, param->hcpu);
 
-        if (task_cpu(param->caller) == cpu)
-                move_task_off_dead_cpu(cpu, param->caller);
-        /* Force idle task to run as soon as we yield: it should
-           immediately notice cpu is offline and die quickly. */
-        sched_idle_next();
         return 0;
 }
 
@@ -223,7 +217,6 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
         void *hcpu = (void *)(long)cpu;
         unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
         struct take_cpu_down_param tcd_param = {
-                .caller = current,
                 .mod = mod,
                 .hcpu = hcpu,
         };
@@ -253,9 +246,12 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
         }
         BUG_ON(cpu_online(cpu));
 
-        /* Wait for it to sleep (leaving idle task). */
-        while (!idle_cpu(cpu))
-                yield();
+        /*
+         * The migration_call() CPU_DYING callback will have removed all
+         * runnable tasks from the cpu, there's only the idle task left now
+         * that the migration thread is done doing the stop_machine thing.
+         */
+        BUG_ON(!idle_cpu(cpu));
 
         /* This actually kills the CPU. */
         __cpu_die(cpu);