From: ebiederm@xmission.com (Eric W. Biederman)
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>,
Davide Libenzi <davidel@xmailserver.org>,
Ingo Molnar <mingo@elte.hu>,
Linus Torvalds <torvalds@linux-foundation.org>,
"Rafael J. Wysocki" <rjw@sisk.pl>,
Roland McGrath <roland@redhat.com>,
Rusty Russell <rusty@rustcorp.com.au>,
linux-kernel@vger.kernel.org, <linux-arch@vger.kernel.org>
Subject: [PATCH] kthread: Simplify kthread_create.
Date: Fri, 13 Apr 2007 21:17:39 -0600 [thread overview]
Message-ID: <m1vefzmyp8.fsf_-_@ebiederm.dsl.xmission.com> (raw)
In-Reply-To: <m1zm5bmywm.fsf@ebiederm.dsl.xmission.com> (Eric W. Biederman's message of "Fri, 13 Apr 2007 21:13:13 -0600")
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
next prev parent reply other threads:[~2007-04-14 3:19 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-13 13:02 [PATCH 3/3] make kthread_stop() scalable Oleg Nesterov
2007-04-13 23:44 ` Eric W. Biederman
2007-04-14 18:02 ` Oleg Nesterov
2007-04-14 18:34 ` Eric W. Biederman
2007-04-14 18:50 ` Oleg Nesterov
2007-04-14 3:13 ` [PATCH] kthread: Enhance kthread_stop to abort interruptible sleeps Eric W. Biederman
2007-04-14 3:17 ` Eric W. Biederman [this message]
2007-04-14 18:35 ` Oleg Nesterov
2007-04-14 19:04 ` Eric W. Biederman
2007-04-14 19:34 ` Oleg Nesterov
2007-04-24 10:09 ` Andrew Morton
2007-04-24 10:30 ` Eric W. Biederman
2007-04-24 10:42 ` Andrew Morton
2007-04-24 11:11 ` Eric W. Biederman
2007-04-24 15:05 ` Oleg Nesterov
2007-04-24 15:53 ` Oleg Nesterov
2007-04-24 17:18 ` Eric W. Biederman
2007-04-24 20:27 ` Oleg Nesterov
2007-04-24 21:19 ` Eric W. Biederman
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