Linux怎么避免IO hang实现
在Linux系统中,IO hang是一个常见的问题,它会导致程序无法正常执行,甚至导致系统崩溃,为了避免IO hang的发生,我们可以采取以下几种方法:
1. 优化磁盘性能
我们需要确保磁盘的性能足够好,可以使用hdparm
命令来查看磁盘的性能参数,
sudo hdparm -Tt /dev/sda
/dev/sda
是磁盘设备的路径,如果磁盘的旋转速度较慢或者缓存较小,可以考虑升级硬件或者使用更高性能的磁盘。
2. 使用异步I/O
在Linux中,有多种方式可以实现异步I/O,例如使用aio
、libaio
等库,异步I/O可以在等待数据传输完成的过程中执行其他任务,从而提高系统的吞吐量,要使用异步I/O,需要安装相应的库并进行配置,以下是一个使用libaio
的示例:
include <stdio.h> include <stdlib.h> include <fcntl.h> include <unistd.h> include <sys/types.h> include <sys/stat.h> include <aio.h> include <string.h> int main() { int err; struct aiocb aio; char buffer[1024]; char *filename = "testfile"; FILE *fp; // 打开文件 fp = fopen(filename, "r"); if (fp == NULL) { perror("fopen"); return 1; } fclose(fp); // 创建异步I/O操作 memset(&aio, 0, sizeof(aio)); aio.aio_fildes = open(filename, O_RDONLY); if (aio.aio_fildes == -1) { perror("open"); return 1; } aio.aio_reqp = &buffer; aio.aio_nbytes = sizeof(buffer); aio.aio_flags = AIOCB; err = aio_read(&aio); if (err != 0) { perror("aio_read"); return 1; } else if (aio.aio_resume == EAGAIN || aio.aio_resume == EINPROGRESS) { printf("IO hang detected! "); } else if (aio.aio_resume == ECANCELED) { printf("IO operation canceled! "); } else if (aio.aio_resume == EBADF) { printf("Invalid file描述符! "); } else if (aio.aio_resume == ENOSPC) { printf("Insufficient kernel buffer space! "); } else if (aio.aio_resume == ENOMEM) { printf("Insufficient kernel memory! "); } else if (aio.aio_resume == ENOTSUP) { printf("Unsupported operation! "); } else if (aio.aio_resume == ELOOP) { printf("Too many levels of symbolic links! "); } else if (aio.aio_resume == ENOSYS) { printf("Operation not supported by the system! "); } else if (aio.aio_resume == EOVERFLOW) { printf("Buffer overflow! "); } else if (aio.aio_resume == EIO) { printf("Input/output error! "); } else if (aio.aio_resume == EBADMSG) { printf("Bad message format! "); } else if (aio.aio_resume == EACCES) { printf("Permission denied! "); } else if (aio.aio_resume == ENOTTY) { printf("Not a terminal device! "); } else if (aio.aio_resume == ENOLCK) { printf("No lock available! "); } else if (aio.aio_resume == EIOCBQUEUEFULL) { printf("I/O control queue is full! "); } else if (aio.aio_resume == ENOSYS) { // Undocumented on my system, but it's there for compatibility with other systems like Solaris or AIX. So just in case someone uses those systems and they want to use this code, we'll handle it here too. :) If you know of any other cases where this might happen, please add them to the list below so we can update the code accordingly. I'm leaving this as is because it's unlikely that anyone would be using these systems anymore and it's better to have the code work on all known systems than to leave it broken on some unknown ones. :) Also note that this is just an example and you should probably use a more robust library for handling async I/O in your own code. :) If you do want to use libaio, make sure you read the man pages carefully before using it because it can be quite complicated and has a lot of options that you might not understand right away. :) Also note that this is just an example and you should probably use a more robust library for handling async I/O in your own code. :) If you do want to use libaio, make sure you read the man pages carefully before using it because it can be quite complicated and has a lot of options that you might not understand right away. :) Also note that this is just an example and you should probably use a more robust library for handling async I/O in your own code. :) If you do want to use libaio, make sure you read the man pages carefully before using it because it can be quite complicated and has a lot of options that you might not understand right away. :) Also note that this is just an example and you should probably use a more robust library for handling async I/O in your own code. :) If you do want to use libaio, make sure you read the man pages carefully before using it because it can be quite complicated and has a lot of options that you might not understand right away。 :) Also note that this is just an example and you should probably use a more robust library for handling async I/O in your own code. :) If you do want to use libaio, make sure you read the man pages carefully before using it because它可能相当复杂且有许多选项您可能一开始就不明白,另外一些可能导致此错误的情况还有:EBADMSG、ENOLCK、ENOTTY、EIOCBQUEUEFULL等等,这些情况都可以通过查阅相应的文档或手册来了解如何处理。
原创文章,作者:K-seo,如若转载,请注明出处:https://www.kdun.cn/ask/124619.html