htop: 进程状态意义

[dushaoshuai]

各工具文档中的进程状态

# man htop
STATE (S)
     The state of the process:
        S for sleeping
        I for idle (longer inactivity than sleeping on platforms that distinguish)
        R for running
        D for disk sleep (uninterruptible)
        Z for zombie (waiting for parent to read its exit status)
        T for traced or suspended (e.g by SIGTSTP)
        W for paging

# man top
S  --  Process Status
          The status of the task which can be one of:
              D = uninterruptible sleep
              I = idle
              R = running
              S = sleeping
              T = stopped by job control signal
              t = stopped by debugger during trace
              Z = zombie
          Tasks  shown  as  running  should  be  more  properly  thought  of  as ready to run  --  their
          task_struct is simply represented on the Linux run-queue.  Even without a  true  SMP  machine,
          you may see numerous tasks in this state depending on top's delay interval and nice value.

# man ps
PROCESS STATE CODES
       Here are the different values that the s, stat and state output specifiers (header "STAT" or  "S")
       will display to describe the state of a process:

               D    uninterruptible sleep (usually IO)
               I    Idle kernel thread
               R    running or runnable (on run queue)
               S    interruptible sleep (waiting for an event to complete)
               T    stopped by job control signal
               t    stopped by debugger during the tracing
               W    paging (not valid since the 2.6.xx kernel)
               X    dead (should never be seen)
               Z    defunct ("zombie") process, terminated but not reaped by its parent

       For BSD formats and when the stat keyword is used, additional characters may be displayed:

               <    high-priority (not nice to other users)
               N    low-priority (nice to other users)
               L    has pages locked into memory (for real-time and custom IO)
               s    is a session leader
               l    is multi-threaded (using CLONE_THREAD, like NPTL pthreads do)
               +    is in the foreground process group

进程状态转换

R [running or runnable (on run queue)]

进程处于就绪态或运行态。

S [interruptible sleep (waiting for an event to complete)]

可中断睡眠状态。进程正在等待某件事发生。进程可以被信号唤醒。

$ sleep 1000 &
[1] 21836
$ kill -15 21836
[1]+  Terminated              sleep 1000
$ jobs -l
$ sleep 1000 &
[1] 21848
$ kill -9 21848
[1]+  Killed                  sleep 1000
$ jobs -l
$

D [uninterruptible sleep (usually IO)]

不可中断睡眠状态。进程正在等待某件事发生。进程不能被信号唤醒。

T [stopped by job control signal]

$ yes > /dev/null
^Z
[1]+  Stopped                 yes > /dev/null
$ ps -o stat,cmd
STAT CMD
...
T    yes
...

t [stopped by debugger during the tracing]

正在被调试器追踪。

Z [for zombie (waiting for parent to read its exit status)]

进程已经退出，不再占用资源，但是父进程还没有读取其退出状态（通过 wait 等系统调用）。

See also

• https://peteris.rocks/blog/htop/#process-state
• https://idea.popcount.org/2012-12-11-linux-process-states/