X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=kernel%2Fkthread.c;h=c848b20b2b083edb517e3b3423e606222e5d331d;hb=987b0145d94eecf292d8b301228356f44611ab7c;hp=fc0767d8461a1d66c950fff2a4b6dcc9de0fcac6;hpb=ec9397bab20a628530ce3051167d3d0fcc2c1af7;p=linux-2.6.git

diff --git a/kernel/kthread.c b/kernel/kthread.c
index fc0767d84..c848b20b2 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -14,6 +14,12 @@
 #include <linux/module.h>
 #include <asm/semaphore.h>
 
+/*
+ * We dont want to execute off keventd since it might
+ * hold a semaphore our callers hold too:
+ */
+static struct workqueue_struct *helper_wq;
+
 struct kthread_create_info
 {
 	/* Information passed to kthread() from keventd. */
@@ -126,12 +132,13 @@ struct task_struct *kthread_create(int (*threadfn)(void *data),
 	init_completion(&create.started);
 	init_completion(&create.done);
 
-	/* If we're being called to start the first workqueue, we
-	 * can't use keventd. */
-	if (!keventd_up())
+	/*
+	 * The workqueue needs to start up first:
+	 */
+	if (!helper_wq)
 		work.func(work.data);
 	else {
-		schedule_work(&work);
+		queue_work(helper_wq, &work);
 		wait_for_completion(&create.done);
 	}
 	if (!IS_ERR(create.result)) {
@@ -157,6 +164,12 @@ void kthread_bind(struct task_struct *k, unsigned int cpu)
 EXPORT_SYMBOL(kthread_bind);
 
 int kthread_stop(struct task_struct *k)
+{
+	return kthread_stop_sem(k, NULL);
+}
+EXPORT_SYMBOL(kthread_stop);
+
+int kthread_stop_sem(struct task_struct *k, struct semaphore *s)
 {
 	int ret;
 
@@ -167,11 +180,14 @@ int kthread_stop(struct task_struct *k)
 
 	/* Must init completion *before* thread sees kthread_stop_info.k */
 	init_completion(&kthread_stop_info.done);
-	wmb();
+	smp_wmb();
 
 	/* Now set kthread_should_stop() to true, and wake it up. */
 	kthread_stop_info.k = k;
-	wake_up_process(k);
+	if (s)
+		up(s);
+	else
+		wake_up_process(k);
 	put_task_struct(k);
 
 	/* Once it dies, reset stop ptr, gather result and we're done. */
@@ -182,4 +198,14 @@ int kthread_stop(struct task_struct *k)
 
 	return ret;
 }
-EXPORT_SYMBOL(kthread_stop);
+EXPORT_SYMBOL(kthread_stop_sem);
+
+static __init int helper_init(void)
+{
+	helper_wq = create_singlethread_workqueue("kthread");
+	BUG_ON(!helper_wq);
+
+	return 0;
+}
+core_initcall(helper_init);
+