运行 dmesg 命令时无法查看设备注册

Question

我正在编译下面的代码

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/miscdevice.h>

unsigned long js,je,diff; 

static int sample_open(struct inode *inode, struct file *file)
{
    pr_info("I have been awoken\n");
    return 0;
}

static int sample_close(struct inode *inodep, struct file *filp)
{
    pr_info("Sleepy time\n");
    return 0;
}

static ssize_t sample_write(struct file *file, const char __user *buf,
                       size_t len, loff_t *ppos)
{
    pr_info("Yummy - I just ate %d bytes\n", len);
    return 1; 
}

static ssize_t sample_read(struct file *filp, char __user *buf,
                    size_t count, loff_t *f_pos)
{
    pr_info("I'm reading something\n");
 
    return 0;
}


static const struct file_operations sample_fops = {
    .owner                      = THIS_MODULE,
    .write                      = sample_write,
    .open                       = sample_open,
    .release            = sample_close,
    .read               = sample_read,
};

struct miscdevice sample_device = {
    .minor = MISC_DYNAMIC_MINOR,
    .name = "lab3",
    .fops = &sample_fops,
};

static int hello_init(void)
{
    js = jiffies;
    printk(KERN_ALERT "Hello, world\n");
    printk("This is the tick time %u", 1000/HZ);
       return 0;
}

static void hello_exit(void)
{
    je = jiffies;
    diff = (je - js)* 1000/HZ;
    printk(KERN_ALERT "Goodbye, cruel world\n");
    printk("This is time difference in seconds %ld %ld s\n", diff / 1000, diff % 1000);
}


static int __init misc_init(void)
{
    int error;
    error = misc_register(&sample_device);
    if (error) {
        pr_err("can't misc_register :(\n");
        return error;
    }

    hello_init();
    return 0;
}

static void __exit misc_exit(void)
{
    misc_deregister(&sample_device);
    hello_exit();
}

module_init(misc_init)
module_exit(misc_exit)

make很好，我正在按预期收到输出。但是当我运行时，dmesg | tail -1我看不到注册的设备号。另外，当我运行时，cat /proc/misc我会看到以下输出

 58 mymisc1
232 kvm
235 autofs
234 btrfs-control
 59 cpu_dma_latency
227 mcelog
236 device-mapper
223 uinput
  1 psaux
196 vfio
200 tun
 60 udmabuf
237 loop-control
 61 lightnvm
183 hw_random
228 hpet
229 fuse
 62 ecryptfs
231 snapshot
242 rfkill
 63 vga_arbiter

我也应该lab3在这里看到我的。我缺少什么建议吗？