示例一,通过class_create()、class_destroy()去注册和注销/sys/class/my_char_dev 代码如下: 1 #include <linux/module.h> 2 #include <linux/init.h> 3 #include <linux/device.h> 4 5 struct class *mem_class; 6 7 static int __init class_create_destroy_init(void) 8 { 9 // class_create...
struct class *__class_create(struct module *owner, const char *name, struct lock_class_key *key) { struct class *cls; int retval; cls = kzalloc(sizeof(*cls), GFP_KERNEL); if (!cls) { retval = -ENOMEM; goto error; } cls->name = name; cls->owner = owner; cls->class_release...
printk("Failed at class_create().Please exec [mknod] before operate the device/n"); } else { device_create(hello_class, NULL, devnum,NULL, devicename); } open_count = 0; langtype = english; inbuffer = (char *)kmalloc(IN_BUF_LEN, GFP_KERNEL); outbuffer = (char *)kmalloc(OUT_...
printk("Failed at class_create().Please exec [mknod] before operate the device/n"); } else { device_create(hello_class, NULL, devnum,NULL, devicename); } open_count = 0; langtype = english; inbuffer = (char *)kmalloc(IN_BUF_LEN, GFP_KERNEL); outbuffer = (char *)kmalloc(OUT_...
struct klist_node knode_class;//连接到设备类的klist struct class *class; //所属设备类 ... }; //所在文件/kernel/drivers/base/base.h struct device_private { struct klist klist_children; //连接子设备 struct klist_node knode_parent; //加入到父设备链表 struct klist_node knode_driver...
echo /sbin/mdev > /proc/sys/kernel/hotplug 该名命令就是用来自动创建设备节点。 udev 是一个工作在用户空间的工具,它能根据系统中硬件设备的状态动态的更新设备文件,包括设备文件的创建,删除,权限等。这些文件通常都定义在/dev 目录下,但也可以在配置文件中指定。udev 必须有内核中的sysfs和tmpfs支持,sysfs 为...
16. cp = kzalloc(sizeof(*cp), GFP_KERNEL); 17. if (!cp) 18. & 62、#160; return -ENOMEM; 19. klist_init(&cp->class_devices, klist_class_dev_get, klist_class_dev_put); 20. INIT_LIST_HEAD(&cp->class_interfaces); 21. kset_init(& 63、;cp->class_dirs); 22. _mutex_init...
class_destroy(chardev_class);cdev_del(&chardev_cdev);unregister_chrdev_region(dev, MINOR_NUM);} static int chardev_open(struct inode *inode, struct file *file){char *str = "helloworld";int ret; struct data *p = kmalloc(sizeof(struct data), GFP_KERNEL...
Linux kernel vfio, https://docs.kernel.org/driver-api/vfio.html IOMMUFD, https://docs.kernel.org/userspace-api/iommufd.html VFIO虚拟化中介设备, https://docs.kernel.org/driver-api/vfio-mediated-device.html vfio-pci 设备特定驱动程序验收标准(vfio-pci-core模块), https://docs.kernel.org/driv...
简单来看,平均负载是指单位时间内,系统处于可运行状态和不可中断状态的平均进程数,也就是平均活跃进程数。实际的计算比较复杂,感兴趣的同学可以查看源码 https://github.com/torvalds/linux/blob/master/kernel/sched/loadavg.c 。 从直观的角度理解,如果平均负载为 2,在 4 核的机器上,表示有 50% 的 CPU 空闲...