Linux Process Management

When we use any operating system will open some applications, then open the program will open a process, we use the Windows system, sometimes open a QQ, while opening a game, you can also open the music playback software, Too many open programs will consume a lot of memory and CPU is the system sometimes feel very lag, then under Linux How to manage the process, and then share with you under the Linux system Linux process management.

1. Static management process
   PS-E listing information about all processes
   
   PID TTY Time CMD
   
   Process 1th is the parent process for all processes Init
   
   Pstree list processes in a tree-like form
   
   Ps-ef
   UID PID PPID C stime TTY time CMD
   Process Owner
   The temporary execution exit does not occupy the state
   
   
   PS AU
   USER PID%cpu%MEM VSZ RSS TTY STAT START
   
   %CPU CPU Usage
   %MEM Memory Utilization
   VSZ Virtual Memory
   RSS Memory Pages
   The process when start starts
   
   PS Axo Pid,pri,nice,%cpu,%mem,command | grep vsftpd
   
   Ps-p PID
   
   PS U-p 6917
   
   -e/-a All Processes
   A All TTY (Bsd-style)
   F Full Format display
   Ppid Show Parent Process
   
   Ps-u root to see which processes are open for a specified user
   
   PS A
   PID TTY STAT Time COMMAND
   
   1. Process ID
   2. Console
   3. Process status
   Status of the STAT process:
   R Running Processes
   S can interrupt the hibernation process
   T Stop/Pause process
   D Non-disruptive process
   Z Zombie Zombie Process
   X exit Status
   s and child processes
   L Lock memory Page memory
   N a process with a lower priority level
   < high-priority processes
   
   4. CPU Time consumption
   5. Name of the process
   
   
   
   
   Ps-ef
   
   PS aux
   
   PS Axo
   
   
   Netstat-tulnp
   
   T: TCP-based protocol
   U: UDP-based protocol
   L:listening Listening If listening indicates that the service is running
   N: Do not do domain name resolution
   P: Process Name
   
   lsof-i:80 See if Port 80 is listening
   
   Pidof vsftpd View the PID of the process (only the PID of the running service can be viewed)
   
   Process dynamic management
   Uptime
   11:30:15 up 2:37, 4 users, Load average:1.02, 1.01, 0.95
   
   How long does the current system time open 4 users average load per 1, 5, 15 minutes
   
   
   Top
   %us User Space Utilization
   %sy kernel Space
   
   PID USER PR NI VIRT RES SHR S%cpu%MEM time+ COMMAND
   1.pid
   2. The owner of the process
   3.PRI Priority
   4.nice value
   5.6
   7.SHR shared Memory The main mechanism for different inter-process access
   8.S process Status
   9.CPU usage Rate
   10. Memory utilization
   11
   12
   
   Top
   P CPU
   M Men
   K-PID
   Z with color display
   Q exit
   
   Top-u redhat Dynamic View Redhat user information
   Top-p 1 view specified PID information
   
   
   
   /proc
   Cat/proc/meminfo Viewing memory status
   Cat/proc/cpuinfo Viewing CPU Details
   
   Route forwarding
   
   Temporary
   Echo 1 >/proc/sys/net/ipv4/ip_forward
   
   Permanent
   echo "Echo 1 >/proc/sys/net/ipv4/ip_forward" >>/etc/rc.local
   
   Configuration file for Environment variables
   ~/.BASHRC ~/.BASH_PROFILE/ETC/PROFILE/ETC/BASHRC
   
   Vim/etc/sysctl.conf
   Net.ipv4.ip_forward = 1
   
   Sysctl-p make current configuration effective immediately
   
   echo 1 >/proc/sys/net/ipv4/icmp_echo_ignore_all Place Ping
   ----------------------------------------------------------------
   Process Management (Kill)
   
   Kill [Signal] PID
   
   Pidof VSFTPD
   6917
   
   Kill 6917
   
   Kill-15 15185
   
   Kill-9 15185 Mandatory
   
   Signal
   Man 7 signal = Kill-l
   
   1 Reload Reload profile does not affect business
   2 CTRL + C Force interrupt
   9 Forced Kill process
   15 Normal Kill Process
   17 Pause
   18 Recovery
   
   Process scheduling (pre-background switchover)
   
   Process foreground:
   Consumes the current shell when the shell shuts down the process ends
   
   Background
   Xeyes & End When the shell closes the process
   
   CTRL + Z puts the foreground running process in the background and is in a stopped state
   
   CTRL + C kills the current process force termination
   
   Nohup Xeyes & Keep the process running in the background without occupying the current shell
   
   
   Pkill httpd Kill process by program name
   
   ------------------------------------------------------------------
   Front and rear switch of process
   
   View Job number
   Jobs
   [1]-Running Xeyes &
   [2]+ Running Xeyes &
   
   A:1, 2 indicates the job number
   b:+ the current process
   -Represents the previous process of the current process
   C: Status
   
   Put the background process in the foreground
   FG%1
   
   CTRL Z---> Background and terminate the foreground process
   
   Keep the background paused process in the background and continue running
   BG%1
   
   Kill%1 kills the process where the first job is located
   ---------------------------------------------------------------------
   Process Priority tuning
   
   Process priority cannot be adjusted directly to the nice value, and the value of the PRI is affected by the Nice value adjustment
   
   Kindness Value Range
   -20 (maximum priority) to 19 (minimum priority)
   
   You can specify a priority when the process is turned on
   PS Axo Pid,nice,pri,command | grep vsftpd
   15220 0 19/USR/SBIN/VSFTPD
   
   Open a process the default nice value is 0 priority 19
   
   The greater the Nice value----the PRI takes precedence (smaller)
   
   Specifies the priority of its operation when the service is opened
   Nice-n 1 Xeyes Nice--->1
   17483 1 Xeyes
   
   Nice-n-1 Firefox & nice--->-1
   
   Adjustments that have been defined for the priority level
   
   Renice-5 17803
   
   Note: The number after Renice is the one you want to end up with -5 (Nice)
   
   
   

   
   

Linux Process Management