delay with atomic works

kernel_module/sleep.c

@@ -0,0 +1,48 @@
+/*
+Usage:
+
+	insmod /sleep.ko
+	rmmod sleep
+
+dmesg prints an integer every second until rmmod.
+
+Since insmod returns, this also illustrates how the work queues are asynchronous.
+*/
+
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h> /* atomic_t */
+#include <linux/workqueue.h>
+
+MODULE_LICENSE("GPL");
+
+static struct workqueue_struct *queue;
+static atomic_t run = ATOMIC_INIT(1);
+
+static void work_func(struct work_struct *work)
+{
+	int i = 0;
+	while (atomic_read(&run)) {
+		printk(KERN_INFO "%d\n", i);
+		usleep_range(1000000, 1000001);
+		i++;
+		if (i == 10)
+			i = 0;
+	}
+}
+
+DECLARE_WORK(work, work_func);
+
+int init_module(void)
+{
+	queue = create_workqueue("myworkqueue");
+	queue_work(queue, &work);
+	return 0;
+}
+
+void cleanup_module(void)
+{
+	atomic_set(&run, 0);
+	destroy_workqueue(queue);
+}