基于内核线程的创建、使用和退出以及延时宏的补充说明介绍

({                                                            /

    struct task_struct *__k                                        /

           = kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); /

    if (!IS_ERR(__k))                                        /

           wake_up_process(__k);                                /

    __k;                                                     /

})

static struct task_struct *my_task = NULL;

static int my_kthread(void *data) 
{ 
    char *mydata = kmalloc(strlen(data)+1,GFP_KERNEL);
    memset(mydata,'\0',strlen(data)+1);
    strncpy(mydata,data,strlen(data));
    while(!kthread_should_stop())
    {
        SLEEP_MILLI_SEC(1000);
        printk("%s\n",mydata);
    }
    kfree(mydata);
    return 0;
} 

static int __init kernel_thread_init(void)
{
    int err;
    printk(KERN_ALERT "Kernel thread initalizing...\n");
    my_task = kthread_create(my_kthread,"hello world","mythread");
    if(IS_ERR(my_task)){
        printk("Unable to start kernel thread./n");
        err = PTR_ERR(my_task);
        my_task = NULL;
        return err;
    }
    wake_up_process(my_task);
    return 0;#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>   //wake_up_process()
#include <linux/kthread.h> //kthread_create(),kthread_run()
#include <linux/err.h> //IS_ERR(),PTR_ERR()
#ifndef SLEEP_MILLI_SEC
#define SLEEP_MILLI_SEC(nMilliSec)\
do { \
long timeout = (nMilliSec) * HZ / 1000; \
while(timeout > 0) \
{ \
timeout = schedule_timeout(timeout); \
} \
}while(0);
#endif

static struct task_struct *my_task = NULL;

static int my_kthread(void *data) 
{ 
    char *mydata = kmalloc(strlen(data)+1,GFP_KERNEL);
    memset(mydata,'\0',strlen(data)+1);
    strncpy(mydata,data,strlen(data));
    while(!kthread_should_stop())
    {
        SLEEP_MILLI_SEC(1000);
        printk("%s\n",mydata);
    }
    kfree(mydata);
    return 0;
} 

static int __init kernel_thread_init(void)
{
    int err;
    printk(KERN_ALERT "Kernel thread initalizing...\n");
    my_task = kthread_create(my_kthread,"hello world","mythread");
    if(IS_ERR(my_task)){
        printk("Unable to start kernel thread./n");
        err = PTR_ERR(my_task);
        my_task = NULL;
        return err;
}

static void __exit kernel_thread_exit(void)
{
    if(my_task){
        printk(KERN_ALERT "Cancel this kernel thread.\n");
        kthread_stop(my_task);
        printk(KERN_ALERT "Canceled.\n");
        }
}

module_init(kernel_thread_init);
module_exit(kernel_thread_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("anonymous");