kthread, timer

kernel_module/kthread.c

@@ -0,0 +1,45 @@
+/*
+Kernel threads are managed exactly like userland threads.
+
+They also have a backing task_struct, and are scheduled with the same mechanism.
+
+See also:
+
+- http://stackoverflow.com/questions/10177641/proper-way-of-handling-threads-in-kernel
+- http://stackoverflow.com/questions/4084708/how-to-wait-for-a-linux-kernel-thread-kthreadto-exit
+*/
+
+#include <linux/delay.h> /* usleep_range */
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+
+MODULE_LICENSE("GPL");
+
+static struct task_struct *kthread;
+
+static int work_func(void *data)
+{
+	int i = 0;
+	while (!kthread_should_stop()) {
+		printk(KERN_INFO "%d\n", i);
+		usleep_range(1000000, 1000001);
+		i++;
+		if (i == 10)
+			i = 0;
+	}
+	return 0;
+}
+
+int init_module(void)
+{
+	kthread = kthread_create(work_func, NULL, "mykthread");
+	wake_up_process(kthread);
+	return 0;
+}
+
+void cleanup_module(void)
+{
+	/* Waits for thread to return. */
+	kthread_stop(kthread);
+}