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-rw-r--r--kernel/kthread.c69
1 files changed, 24 insertions, 45 deletions
diff --git a/kernel/kthread.c b/kernel/kthread.c
index 4dcbc8b5d6b6..01d27164e5b7 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -78,21 +78,6 @@ void free_kthread_struct(struct task_struct *k)
kfree(to_kthread(k));
}
-#define __to_kthread(vfork) \
- container_of(vfork, struct kthread, exited)
-
-/*
- * TODO: kill it and use to_kthread(). But we still need the users
- * like kthread_stop() which has to sync with the exiting kthread.
- */
-static struct kthread *to_live_kthread(struct task_struct *k)
-{
- struct completion *vfork = ACCESS_ONCE(k->vfork_done);
- if (likely(vfork))
- return __to_kthread(vfork);
- return NULL;
-}
-
/**
* kthread_should_stop - should this kthread return now?
*
@@ -441,8 +426,18 @@ struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
return p;
}
-static void __kthread_unpark(struct task_struct *k, struct kthread *kthread)
+/**
+ * kthread_unpark - unpark a thread created by kthread_create().
+ * @k: thread created by kthread_create().
+ *
+ * Sets kthread_should_park() for @k to return false, wakes it, and
+ * waits for it to return. If the thread is marked percpu then its
+ * bound to the cpu again.
+ */
+void kthread_unpark(struct task_struct *k)
{
+ struct kthread *kthread = to_kthread(k);
+
clear_bit(KTHREAD_SHOULD_PARK, &kthread->flags);
/*
* We clear the IS_PARKED bit here as we don't wait
@@ -460,22 +455,6 @@ static void __kthread_unpark(struct task_struct *k, struct kthread *kthread)
wake_up_state(k, TASK_PARKED);
}
}
-
-/**
- * kthread_unpark - unpark a thread created by kthread_create().
- * @k: thread created by kthread_create().
- *
- * Sets kthread_should_park() for @k to return false, wakes it, and
- * waits for it to return. If the thread is marked percpu then its
- * bound to the cpu again.
- */
-void kthread_unpark(struct task_struct *k)
-{
- struct kthread *kthread = to_live_kthread(k);
-
- if (kthread)
- __kthread_unpark(k, kthread);
-}
EXPORT_SYMBOL_GPL(kthread_unpark);
/**
@@ -492,20 +471,20 @@ EXPORT_SYMBOL_GPL(kthread_unpark);
*/
int kthread_park(struct task_struct *k)
{
- struct kthread *kthread = to_live_kthread(k);
- int ret = -ENOSYS;
-
- if (kthread) {
- if (!test_bit(KTHREAD_IS_PARKED, &kthread->flags)) {
- set_bit(KTHREAD_SHOULD_PARK, &kthread->flags);
- if (k != current) {
- wake_up_process(k);
- wait_for_completion(&kthread->parked);
- }
+ struct kthread *kthread = to_kthread(k);
+
+ if (WARN_ON(k->flags & PF_EXITING))
+ return -ENOSYS;
+
+ if (!test_bit(KTHREAD_IS_PARKED, &kthread->flags)) {
+ set_bit(KTHREAD_SHOULD_PARK, &kthread->flags);
+ if (k != current) {
+ wake_up_process(k);
+ wait_for_completion(&kthread->parked);
}
- ret = 0;
}
- return ret;
+
+ return 0;
}
EXPORT_SYMBOL_GPL(kthread_park);
@@ -534,7 +513,7 @@ int kthread_stop(struct task_struct *k)
get_task_struct(k);
kthread = to_kthread(k);
set_bit(KTHREAD_SHOULD_STOP, &kthread->flags);
- __kthread_unpark(k, kthread);
+ kthread_unpark(k);
wake_up_process(k);
wait_for_completion(&kthread->exited);
ret = k->exit_code;