kthread/smpboot: do not park in kthread_create_on_cpu()

[deliverable/linux.git] / kernel / kthread.c

diff --git a/kernel/kthread.c b/kernel/kthread.c
index 20bdf2c8d0f5fe02ebd075b55ba370f9f77e50bf..33058a4eeff6eb4724427c5fd124bb01979a76f3 100644 (file)
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -390,10 +390,10 @@ struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
                                   cpu);
        if (IS_ERR(p))
                return p;
+       kthread_bind(p, cpu);
+       /* CPU hotplug need to bind once again when unparking the thread. */
        set_bit(KTHREAD_IS_PER_CPU, &to_kthread(p)->flags);
        to_kthread(p)->cpu = cpu;
-       /* Park the thread to get it out of TASK_UNINTERRUPTIBLE state */
-       kthread_park(p);
        return p;
 }
 
@@ -407,6 +407,10 @@ static void __kthread_unpark(struct task_struct *k, struct kthread *kthread)
         * which might be about to be cleared.
         */
        if (test_and_clear_bit(KTHREAD_IS_PARKED, &kthread->flags)) {
+               /*
+                * Newly created kthread was parked when the CPU was offline.
+                * The binding was lost and we need to set it again.
+                */
                if (test_bit(KTHREAD_IS_PER_CPU, &kthread->flags))
                        __kthread_bind(k, kthread->cpu, TASK_PARKED);
                wake_up_state(k, TASK_PARKED);