当一个设备驱动需要处理它的硬件的反应时间, 涉及到的延时常常是最多几个毫秒. 在这 个情况下, 依靠时钟嘀哒显然不对路. The kernel functions ndelay, udelay, and mdelay serve well for short delays, delaying execution for the specified number of nanoseconds, microseconds, or milliseconds respectively.* Their p
service mysql start出错,mysql启动不了,解决mysql: unrecognized service错误的方法如下: [hitony ~]# service mysql startmysql: unrecognized service[hitony ~]# service mysql restartmysql: unrecognized service [hitony ~]# rpm -q mysql 查询发现mysql已经正常安装mysql-5.1.52-jason.1
一.防火墙 防火墙根据配置文件/etc/sysconfig/iptables 来控制本机的“出.入”网络访问行为 其对行为的配置策略有四个策 1. 基础必备技能 查看防火墙状态 service iptables status 开启防火墙 service iptables start 关闭防火墙 service iptables stop 关闭防火墙开机自启 chkconfig iptables off