于是在OS底层给磁盘r/w准备cache，也就是UNIX给block device准备cache，以提高性能。
static int device_close(struct inode *indoe, struct file *file) { printk("device close\n"); if(buf) { kfree(buf); } return 0; } static int device_mmap(struct file *file, struct vm_area_struct *vma) { vma->vm_flags |= VM_IO;//表示对设备IO空间的映射 vma->vm_flags |= VM_...
#define readw(addr) (*(volatile unsigned short *) __io_virt(addr)) #define readl(addr) (*(volatile unsigned int *) __io_virt(addr)) #define writeb(b,addr) (*(volatile unsigned char *) __io_virt(addr) = (b)) #define writew(b,addr) (*(volatile unsigned short *) __io_vi...
AI代码解释 #include<linux/module.h>#include<linux/kernel.h>#include<linux/init.h>#include<linux/mm.h>#include<linux/miscdevice.h>#defineMISC_DEV_MINOR5staticchar*kbuff;staticssize_tmisc_dev_read(struct file*filep,char __user*buf,size_t count,loff_t*offset){int ret;size_t len=(count...
platform_device.h>#include<linux/miscdevice.h>#include<asm/mach/map.h>#include<asm/uaccess.h>#include<asm/io.h>#include<linux/mm.h>#include<linux/slab.h>#include<linux/fs.h>char* mmap_buf =NULL;staticssize_twyr_write(structfile *filp,constchar__user *buf,size_tcnt,loff_t*offt)...
staticint device_mmap(struct file *file,struct vm_area_struct *vma) { vma->vm_flags |= VM_IO;//表示对设备IO空间的映射 vma->vm_flags |= VM_RESERVED;//标志该内存区不能被换出,在设备驱动中虚拟页和物理页的关系应该是长期的,应该保留起来,不能随便被别的虚拟页换出 ...
用户可以从 milvus repo 中获取 docker-compose.yml 文件,地址https://github.com/milvus-io/milvus/blob/master/deployments/docker/gpu/standalone/docker-compose.yml 至此,便可完成 standalone 模式的 Milvus 部署。 如果用户宿主机有多张显卡,可以通过修改 docker-compose.yml 中的 device_ids 字段来修改映射到...
#include linux/device.h #define DEV_NAME mmapled struct mmapled { dev_t devno; struct cdev mcdev; struct class *mmap_class; }; structmmapled *mpt; intmmapled_open(struct inode *inode, struct file *filp) { printk(In kernel open,major =%d,minor =%d\n,MAJOR(mpt->devno),MINOR(mpt...
LINUX IO STACK DIAGRAM i'm programmer A high-level overview of the Linux IO stack diagram relating its various layers. This diagram shows a relationship between applications, the VFS layer, block layer, I/O schedulers, SCSI layers, various device drivers, and physical devices. ...
Hi, I know this issue has already been talked about, but I got the following issue: running sudo pigpiod returns: initPeripherals: mmap gpio failed (Operation not permitted) Can't initialise pigpio library I tried adding iomem=relaxed to...