[SOLVED] How to kill uninterruptible process?

[blnl]

Often I get the following message when starting FireFox:

Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.

At the same time CPU usage goes to 100%, load is extremely high and my PC is becoming unresponsive.

I tried killing the process:

killall -9 firefox

but without success.

In the System Monitor I see that firefox is marked as "uninterruptible" process.

Two questions:
Why is this happening?
How to kill such an uninteruptible process?

[RDU]

above kill -9, I think there is only reboot...
But are you running 64 bit and have openned PDF file in the browser ? There is some old version of Adobe reader plugin wich hang on 64 bits, so make the browser hang. In this case, check to kill those acroread process (kill -9) and it will free the browser itself.

[blnl]

No, I'm running 32 bit. No PDF is opened in the browser.

I tried removing
.mozilla/firefox/profile.default/lock and
.mozilla/firefox/profile.default/.parentlock, but it didn't help.

By the way, the issue started a week ago, after consuming a bunch of fedora12 updates.

[blnl]

I believe I solved it! (by reinstalling firefox and thunderbird)

yum reinstall firefox
yum reinstall thunderbird

Everything seems to be normal again (no annoying error messages, no uninteruptible processes, CPU load is normal).

[Segfault]

Another utility is xkill, it works differently, forces X server to close connection to the client. Works even when process is not listening - and thus not reponding to kill command.

[blnl]

Another utility is xkill, it works differently, forces X server to close connection to the client. Works even when process is not listening - and thus not reponding to kill command.

Thanks a lot!
This can be very useful.

[Segfault]

You are welcome!

The problem with kill (pkill, killall) command is it is a signal sent to the process. If the process in question is stuck it may not be listening to signals sent to it. The only solution is to kill the parent process. If parent is init ... then it looks like reboot. BTW, pstree command will display it rather nicely.
Luckily enough in X server you can choose which child to terminate using xkill.