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Subject[PATCH] kthread: Simplify kthread_create.
Date

This removes an unneeded completion from kthread_create and moves
wake_up_process out of the kthread_create_lock making it clear that
wake_up_process doesn't need the protection of the
kthread_create_lock.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
kernel/kthread.c | 16 ++++++----------
1 files changed, 6 insertions(+), 10 deletions(-)
diff --git a/kernel/kthread.c b/kernel/kthread.c
index 06c7e51..cd89b49 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -24,7 +24,6 @@ struct kthread_create_info
/* Information passed to kthread() from kthreadd. */
int (*threadfn)(void *data);
void *data;
- struct completion started;

/* Result passed back to kthread_create() from kthreadd. */
struct task_struct *result;
@@ -41,6 +40,9 @@ static int kthread(void *_create)
void *data;
int ret = -EINTR;

+ /* Report which task_struct I am */
+ create->result = current;
+
/* Setup a completion on this thread's stack */
init_completion(&done);
current->vfork_done = &done;
@@ -51,7 +53,7 @@ static int kthread(void *_create)

/* OK, tell user we're spawned, wait for stop or wakeup */
__set_current_state(TASK_INTERRUPTIBLE);
- complete(&create->started);
+ complete(&create->done);
schedule();

if (!kthread_should_stop())
@@ -68,13 +70,8 @@ static void create_kthread(struct kthread_create_info *create)
pid = kernel_thread(kthread, create, CLONE_FS | CLONE_FILES | SIGCHLD);
if (pid < 0) {
create->result = ERR_PTR(pid);
- } else {
- wait_for_completion(&create->started);
- read_lock(&tasklist_lock);
- create->result = find_task_by_pid(pid);
- read_unlock(&tasklist_lock);
+ complete(&create->done);
}
- complete(&create->done);
}

/**
@@ -105,14 +102,13 @@ struct task_struct *kthread_create(int (*threadfn)(void *data),

create.threadfn = threadfn;
create.data = data;
- init_completion(&create.started);
init_completion(&create.done);

spin_lock(&kthread_create_lock);
list_add_tail(&create.list, &kthread_create_list);
- wake_up_process(kthreadd_task);
spin_unlock(&kthread_create_lock);

+ wake_up_process(kthreadd_task);
wait_for_completion(&create.done);

if (!IS_ERR(create.result)) {
--
1.5.0.g53756
-
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