写一段内核代码定期执行打印时间的任务,但是当系统休眠或者panic的时候停止打印
时间: 2023-05-29 10:05:49 浏览: 112
以下是一段内核代码,定期执行打印时间的任务,但是在系统休眠或panic时停止打印:
```
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/timer.h>
#include <linux/suspend.h>
static struct timer_list my_timer;
static void print_time(unsigned long data)
{
printk(KERN_INFO "Current time: %ld\n", (long)jiffies);
mod_timer(&my_timer, jiffies + msecs_to_jiffies(1000)); // 1 second interval
}
static int __init my_init(void)
{
printk(KERN_INFO "Starting time printing task...\n");
setup_timer(&my_timer, print_time, 0);
mod_timer(&my_timer, jiffies + msecs_to_jiffies(1000)); // start after 1 second
return 0;
}
static void __exit my_exit(void)
{
del_timer_sync(&my_timer);
printk(KERN_INFO "Stopping time printing task...\n");
}
static int my_suspend(void)
{
del_timer_sync(&my_timer);
return 0;
}
static int my_resume(void)
{
mod_timer(&my_timer, jiffies + msecs_to_jiffies(1000)); // resume after 1 second
return 0;
}
static struct syscore_ops my_syscore_ops = {
.suspend = my_suspend,
.resume = my_resume,
};
module_init(my_init);
module_exit(my_exit);
MODULE_LICENSE("GPL");
static int __init my_init(void)
{
printk(KERN_INFO "Starting time printing task...\n");
setup_timer(&my_timer, print_time, 0);
mod_timer(&my_timer, jiffies + msecs_to_jiffies(1000)); // start after 1 second
register_syscore_ops(&my_syscore_ops);
return 0;
}
static void __exit my_exit(void)
{
unregister_syscore_ops(&my_syscore_ops);
del_timer_sync(&my_timer);
printk(KERN_INFO "Stopping time printing task...\n");
}
static int my_suspend(void)
{
del_timer_sync(&my_timer);
return 0;
}
static int my_resume(void)
{
mod_timer(&my_timer, jiffies + msecs_to_jiffies(1000)); // resume after 1 second
return 0;
}
static struct syscore_ops my_syscore_ops = {
.suspend = my_suspend,
.resume = my_resume,
};
module_init(my_init);
module_exit(my_exit);
MODULE_LICENSE("GPL");
```
这段代码在内核初始化时会注册一个定时器,每隔1秒打印一次当前时间。如果系统进入睡眠状态,定时器会被删除,直到系统恢复为止。如果系统panic,则定时器也会停止。为了处理系统休眠和恢复,这段代码还注册了一个syscore操作,用于在系统进入和退出休眠状态时启动和停止定时器。
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