WCHAN in ‘ps -l’

on Linux/x86, ps -l command gives a long listing. Field WCHAN in the listing caught my interest.

-bash-2.05b# ps -l
F S   UID   PID  PPID  C PRI  NI ADDR    SZ WCHAN  TTY          TIME CMD
4 S     0    21597 21595  0  76   0    –           1096 wait4  pts/2    00:00:00 bash
4 R     0   21677 21597  0  80   0    –            794    –      pts/2    00:00:00 ps

looking at the man page, I could find out what it displays –

WCHAN    address of the kernel function where the process is sleeping (use wchan if   you want the kernel function name). Running tasks will display a dash (’-’) in this column.

‘ps -l’ uses System.Map file for reading the symbols.

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2 thoughts on “WCHAN in ‘ps -l’

  1. Hi,

    hmmm… Well i came by your blog entry while trying my best to find out what those fields exactly mean? I typed “man ps” as well but couldn’t find the descriptions… Can’t say i read the whole manual page anyway 🙂 But according to what i found out, “WCHAN” stands for waiting channel and it means: “The address of an event on which the process is waiting”. This I got from the following site. “http://www.linux-tutorial.info”.. U wudn’t know what the others mean do you… If you do can you drop a comment at my blog please?

    Thanks…
    TC

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