What do those brackets mean when using the "ps" command?

[SharpyWarpy]

Exactly what do those brackets [ and ] mean when using the ps command?
The reason I'm asking is when I try to kill one of these processes it won't die.
Observe the following:
code:
12:18 PM ~ # ps ax
PID TTY STAT TIME COMMAND
1 ? Ss 0:00 init [3]
2 ? S 0:00 [migration/0]
3 ? SN 0:00 [ksoftirqd/0]
4 ? S 0:00 [watchdog/0]
5 ? S< 0:00 [events/0]
6 ? S< 0:00 [khelper]
7 ? S< 0:00 [kthread]
46 ? S< 0:00 [kblockd/0]
47 ? S< 0:00 [kacpid]
142 ? S< 0:00 [cqueue/0]
143 ? S< 0:00 [ksuspend_usbd]
146 ? S< 0:00 [khubd]
148 ? S< 0:00 [kseriod]
168 ? S 0:00 [pdflush]
169 ? S< 0:00 [kswapd0]
170 ? S< 0:00 [aio/0]
309 ? S< 0:00 [kpsmoused]
335 ? S< 0:00 [ata/0]
336 ? S< 0:00 [ata_aux]
341 ? S< 0:00 [scsi_eh_0]
342 ? S< 0:00 [scsi_eh_1]
348 ? S< 0:00 [scsi_eh_2]
349 ? S< 0:00 [scsi_eh_3]
352 ? S< 0:00 [scsi_eh_4]
353 ? S< 0:00 [usb-storage]
361 ? S< 0:00 [kjournald]
389 ? S< 0:00 [kauditd]
426 ? S<s 0:00 /sbin/udevd -d
1123 ? S< 0:00 [kgameportd]
1339 ? S< 0:00 [kmpathd/0]
1345 ? S< 0:00 [kmirrord]
1372 ? Ss 0:00 /sbin/mount.ntfs-3g /dev/sdb1 /mnt/win -o rw
1373 ? S< 0:00 [kjournald]
1375 ? S< 0:00 [kjournald]
1377 ? S< 0:00 [kjournald]
1580 ? Ss 0:00 syslogd -m 0
1583 ? Ss 0:00 klogd -x
1628 ? Ss 0:00 dbus-daemon --system
1690 ? Ss 0:00 cupsd
1706 ? Ss 0:00 gpm -m /dev/input/mice -t exps2
1722 ? Ss 0:00 crond
1758 ? Ss 0:00 xfs -droppriv -daemon
1772 ? Ss 0:00 login -- rbandmb
1775 tty3 Ss+ 0:00 /sbin/mingetty tty3
1777 tty4 Ss+ 0:00 /sbin/mingetty tty4
1781 tty5 Ss+ 0:00 /sbin/mingetty tty5
1784 tty6 Ss+ 0:00 /sbin/mingetty tty6
1810 tty1 Ss 0:02 -bash
2230 ? S 0:00 [pdflush]
2268 ? Ss 0:00 login -- rbandmb
2302 tty2 Ss+ 0:00 -bash
2468 ttyS0 Ss+ 0:00 pppd
2479 tty1 S+ 0:00 xinit
2480 tty7 S<Ls+ 0:22 X :0
2484 ? Ssl 0:00 gnome-session
2487 ? Z 0:00 [beryl-manager] <defunct>
2488 ? Ssl 0:00 beryl-manager
2496 ? S 0:00 /usr/libexec/gconfd-2 5
2556 ? S 0:00 /usr/bin/gnome-keyring-daemon
2561 ? S 0:00 dbus-launch --autolaunch 91cad7b5c9088effa89d610047244300 --binary-syntax
2565 ? Ss 0:00 dbus-daemon --fork --print-address 16 --print-pid 18 --session
2567 ? Sl 0:00 /usr/libexec/gnome-settings-daemon
2568 ? Ss 0:00 /bin/dbus-daemon --fork --print-pid 6 --print-address 8 --session
2577 ? S 0:00 emerald --replace
2587 ? RL 0:07 beryl --xgl-rendering --force-nvidia --skip-gl-yield
2596 ? S 0:00 nautilus --sm-config-prefix /nautilus-CuJgNr/ --sm-client-id 117f0000010001
2598 ? S 0:01 gnome-panel --sm-config-prefix /gnome-panel-FYirWt/ --sm-client-id 117f0000
2612 ? Ssl 0:00 /usr/libexec/bonobo-activation-server --ac-activate --ior-output-fd=16
2616 ? S 0:00 /usr/bin/pam-panel-icon --sm-client-id 117f00000100011973454790000004222000
2617 ? S 0:00 /sbin/pam_timestamp_check -d root
2619 ? S 0:00 /usr/libexec/gnome-vfs-daemon
2634 ? S 0:00 /usr/libexec/wnck-applet --oaf-activate-iid=OAFIID:GNOME_Wncklet_Factory --
2636 ? S 0:00 /usr/libexec/trashapplet --oaf-activate-iid=OAFIID:GNOME_Panel_TrashApplet_
2638 ? S 0:00 /usr/libexec/mapping-daemon
2662 ? S 0:00 /usr/libexec/notification-area-applet --oaf-activate-iid=OAFIID:GNOME_Notif
2664 ? S 0:00 /usr/libexec/clock-applet --oaf-activate-iid=OAFIID:GNOME_ClockApplet_Facto
2666 ? S 0:00 /usr/libexec/mixer_applet2 --oaf-activate-iid=OAFIID:GNOME_MixerApplet_Fact
2668 ? S 0:00 /usr/libexec/fast-user-switch-applet --oaf-activate-iid=OAFIID:GNOME_FastUs
2673 ? S 0:00 /bin/sh /rbandmb/swiftfox/swiftfox -width 1024 -height 768
2680 ? S 0:00 /bin/sh /rbandmb/swiftfox/run-mozilla.sh /rbandmb/swiftfox/swiftfox-bin -wi
2686 ? Sl 0:25 /rbandmb/swiftfox/swiftfox-bin -width 1024 -height 768
2716 ? Sl 0:00 gnome-terminal --window-with-profile=ray --title=Terminal
2718 ? S 0:00 gnome-pty-helper
2719 pts/0 Ss 0:00 bash
2740 pts/0 R+ 0:00 ps ax

When I try to kill process, say,
1345 ? S< 0:00 [kmirrord]
with the following commands
"kill 1345" or "killall kmirrord"
it does nothing, nor so for any running process name enclosed within brackets.
Thanks ahead of time.

[Nokia]

Right now I don't have a precise answer for you, but I know a great place to start looking for answers. Please issue

man ps

Also, keep in mind that you are allowed to kill your processes ONLY. Unles you are root, you're not able to terminate other users processes.
You also might wanna try issuing

ps aux

next time to gain acces to more useful bits of info.

[SharpyWarpy]

Originally Posted by Nokia

Right now I don't have a precise answer for you, but I know a great place to start looking for answers. Please issue

Also, keep in mind that you are allowed to kill your processes ONLY. Unles you are root, you're not able to terminate other users processes.
You also might wanna try issuing next time to gain acces to more useful bits of info.

Well, I already studied the manuals for ps and kill, they weren't much help, really. As for being root, that's how I started, became root user then tried kill, killall, etc. with the same results. I'm trying to gain more knowledge of Linux in general, I suppose I might need to post this thread on linuxquestions.org.

[Nokia]

Although I doubt it would help u=you very much, try

kill -l

to see a list of available kill commands. The default signal when issuing kill is 15. In translation that would mean Kill asks the process to close and (if I'm not mistaking) awaits for a confirmation from the process.
The second most use signal is -9, which sounds like "I don't care what you do, close right away"

And a personal advice, if you don't mind: Extremely rare are situations when you might get an answer for very basic and omnipresent questions and answers, which have been dealt with for a long time. Use your favourite search engine first. That might be enough more often that you can imagine And by doing that, you could save time and give a chance for those who gained more knowledge in time to get the chance to answer to more serious situations.

[adrianx]

Hi,

As far as I can tell, those( [...] ) are kernel processes. Some processes re-spawn (for various reasons) when you try to kill them. This is especially true when you try to kill a child process.

I normally use ps -ef. There is a column called PPID, this refers to the Parent Process ID. Try killing the parent process first.

[SharpyWarpy]

Originally Posted by adrianx

Hi,

As far as I can tell, those( [...] ) are kernel processes. Some processes re-spawn (for various reasons) when you try to kill them. This is especially true when you try to kill a child process.

I normally use ps -ef. There is a column called PPID, this refers to the Parent Process ID. Try killing the parent process first.

Thank you, adrianx for your informative reply.
"kernel processes", would that be something compiled into the kernel? Could that be why I can't stop it? Would I have to compile the kernel with this function compiled as a module and not integrated into the kernel in order to make sure it's not running all the time?
I tried stopping the parent process first and it wouldn't stop either, that of "kthread", whatever that is, I suspect it's something to do with KDE? I don't like processes running that I don't know what they are, call me paranoid, but I like all my resources running for me only.

[markkuk]

kthreadd is the kernel thread daemon, it has nothing to do with KDE. Its job is to start the other kernel threads. See: http://lxr.linux.no/linux/kernel/kthread.c#L217

[adrianx]

This is basically what kthreadd is responsible for:

These “kthreads” (kernel threads) are used to implement system functions and to handle interrupts and such background tasks as disk buffering. Some kthreads are used to execute the code of threads in user-level programs.

You seem to be using GNOME, so have a look at System > Administration > Services (you'll be prompted to enter your root password). Before disabling/enabling anything, I suggest that you have a look at this: http://dnmouse.webs.com/services.htm.

[SharpyWarpy]

Originally Posted by markkuk

kthreadd is the kernel thread daemon, it has nothing to do with KDE. Its job is to start the other kernel threads. See: http://lxr.linux.no/linux/kernel/kthread.c#L217

Thank you markkuk for the useful info, I've read some of the link you posted, I don't understand it but I'll keep studying.

adrianx, thank you, I've had a look at services config, stopped all from running I don't need, studied enough to know which ones are not for me.
Very helpful, both of you.