Linux可以使用nice命令修改程序的优先级
介绍
- Linux 运行 COMMAND 通过
优先级(niceness) 影响进程调度
优先级 值范围从 -20（对进程最有利）到 19（对进程最不利）
- 优先级的值越低，优先级越高
- 优先级的值越高，优先级越低
安装
apt install coreutils
$ dpkg -S `which nice`
coreutils: /usr/bin/nice
help
$ nice --help
Usage: nice [OPTION] [COMMAND [ARG]...]
Run COMMAND with an adjusted niceness, which affects process scheduling.
With no COMMAND, print the current niceness. Niceness values range from
-20 (most favorable to the process) to 19 (least favorable to the process).
Mandatory arguments to long options are mandatory for short options too.
-n, --adjustment=N add integer N to the niceness (default 10)
--help display this help and exit
--version output version information and exit
NOTE: your shell may have its own version of nice, which usually supersedes
the version described here. Please refer to your shell's documentation
for details about the options it supports.
Exit status:
125 if the nice command itself fails
126 if COMMAND is found but cannot be invoked
127 if COMMAND cannot be found
- the exit status of COMMAND otherwise
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Full documentation <https://www.gnu.org/software/coreutils/nice>
or available locally via: info '(coreutils) nice invocation'
使用
程序运行前修改
# 以最高优先级运行
$ nice -n-20 bash xxx.sh
# 以最低优先级运行
$ nice -n19 bash xxx.sh
修改运行中的程序
renice -20 PID
renice -19 PID
$ top # 输入 r 后提示 `PID to renice [default pid = 2161]` 输入pid或回车后，提示 `Renice PID 2161 to value`，输入需要的优先级回车即可
查看优先级
$ ps -lef | more
F S UID PID PPID C PRI NI ADDR SZ WCHAN STIME TTY TIME CMD
4 S root 1 0 0 80 0 - 5535 ep_pol 14:08 ? 00:00:02 /sbin/init
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1 root 20 0 22140 13384 9544 S 0.0 0.3 0:02.39 systemd