Linux nice和renice命令：改变进程优先级

nice命令

[root@localhost ~] # nice [-n NI值] 命令

[root@localhost ~]# service httpd start
[root@localhost ~]# ps -le 丨 grep "httd" | grep -v grep
F S UID PID PPID C PRI NI ADDR SZ WCHAN TTY TIME CMD
1 S 0 2084 1 0 80 0 - 1130 - ? 00:00:00 httpd
5 S 2 2085 2084 0 80 0 - 1130 - ? 00:00:00 httpd
5 S 2 2086 2084 0 80 0 - 1130 - ? 00:00:00 httpd
5 S 2 2087 2084 0 80 0 - 1130 - ? 00:00:00 httpd
5 S 2 2088 2084 0 80 0 - 1130 - ? 00:00:00 httpd
5 S 2 2089 2084 0 80 0 - 1130 - ? 00:00:00 httpd
#用默认优先级自动apache服务，PRI值是80，而NI值是0
[root@localhost ~]# service httpd stop
#停止apache服务
[root@localhost ~]# nice -n -5 service httpd start
#启动apache服务，同时修改apache服务进程的NI值为-5
[rooteiocdlhost ~]# ps -le | grep "httpd" | grep -v grep
F S UID PID PPID C FRI NI ADDR SZ WCHAN TTY TIME CMD
1 S 0 2122 1 0 75 -5 - 1130 - ? 00:00:00 httpd
5 S 2 2123 2122 0 75 -5 - 1130 - ? 00:00:00 httpd
5 S 2 2124 2122 0 75 -5 - 1130 - ? 00:00:00 httpd
5 S 2 2125 2122 0 75 -5 - 1130 - ? 00:00:00 httpd
5 S 2 2126 2122 0 75 -5 - 1130 - ? 00:00:00 httpd
5 S 2 2127 2122 0 75 -5 - 1130 - ? 00:00:00 httpd
#httpd进程的PRI值变为了75，而NI值为-5

renice 命令

[root@localhost ~] # renice [优先级] PID

[root@localhost ~]# renice -10 2125
2125: old priority -5, new priority -10
[root@localhost ~]# ps -le | grep "httpd" | grep -v grep
1 S 0 2122 1 0 75 -5 - 113.0 - ? 00:00:00 httpd
5 S 2 2123 2122 0 75 -5 - 1130 - ? 00:00:00 httpd
5 S 2 2124 2122 0 75 -5 - 1130 - ? 00:00:00 httpd
5 S 2 2125 2122 0 70 -10 - 1130 - ? 00:00:00 httpd
5 S 2 2126 2122 0 75 -5 - 1130 - ? 00:00:00 httpd
5 S 2 2.127 2122 0 75 -5 - 1130 - ? 00:00:00 httpd
#PID为2125的进程的PRI值为70，而NI值为-10