Linux进程管理(一)

Linux进程管理(一)

😄 Written by Zak Zhu

目录

• Linux进程管理(一)
  • 参考
  • pstree命令
  • pidof命令
  • pmap命令
  • pwdx命令
  • ps命令
  • nice调优
  • 发送信号

参考

• 马哥linux视频
• u013184884/利用pwdx查看Linux程序的工作目录(https://blog.csdn.net/u013184884/article/details/82993286)
• 菲宇/Linux进程内存分析pmap命令(https://blog.csdn.net/bbwangj/article/details/80698291)
• RHCE培训(RH033-Unit10)

pstree命令

pstree -p

pidof命令

根据服务名, 查找进程号

e.g. pidof named

Tips: pidof的命令退出码($?)不为0时, 表示服务没有起来

pmap命令

pmap - report memory map of a process

pmap [OPTIONS] PID...
Options:
	-x		# show details
	-d 		# show offset and device number

1. e.g. pmap -d 1

   

   • Address # start address of map
   • Kbytes # size of map in kilobytes
   • RSS # resident set size in kilobytes
   • Dirty # dirty pages (both shared and private) in kilobytes
   • Mode # permissions on map
   • Mapping # file backing the map, or '[ anon ]' for allocated memory, or '[ stack ]' for the program stack
   • Offset # offset into the file
   • Device # device name
   • mapped # Virtual memory set size
   • writeable/private # Real used memory
   • shared # Shared memory

2. e.g. pmap -x 1

   

pwdx命令

在工作中, 我们经常会看到多个相似的进程同时运行. 有时候, 需要对其中一两个进程进行操作, 比如杀掉, 也会经常担心杀错.

pwdx命令, 利用进程号作为参数, 可以打印出指定进程号的工作目录, 帮助我们区分不同的进程

pwdx PID

ps命令

ps -efH
ps -eHo user,group,pid,ppid,stat,%cpu,psr,%mem,ni,cmd,time

Process State Codes:

man ps

• D # uninterruptible sleep (usually IO)
• R # running
• S # interruptible sleep (waiting for an event to complete)
• T # stopped by job control signal
• t # stopped by debugger during the tracing
• X # dead (should never be seen)
• Z # zombie process, terminated but not reaped by its parent

additional characters may be displayed:

• < # high-priority
• N # lower-priority
• L # has pages locked into memory (for real-time and custom IO)
• s # is a session leader
• l # is multi-threaded
• + # is in the foreground process group

nice调优

Scheduling priority determines access to the CPU

Priority is affected by a process' nice value

Values range from -20 to 19 but default to 0

Lower nice value means higher CPU priority

Nice value may be altered ...

• When starting a process:

  e.g. nice -n 5 COMMAND

• Afer starting:

  e.g. renice -n 5 PID

发送信号

Signal	Value	Comment
SIGHUP	1	让程序重读配置文件, 而不用重启程序
SIGINT	2	中断信号(Ctrl + C即发送该信号)
SIGKILL	9	暴力杀死进程
SIGTERM	15	温柔终止进程(默认)

• By PID

  kill -SIGNAL PID
  

• By Pattern

  pkill -SIGNAL PATTERN