killer vs. Xreset.d

[Petter Reinholdtsen <pere@hungry.com>]

Hi,

The discussion in <URL: https://bugs.debian.org/890517 > reminded me of
why we introduced the killer package in Debian Edu.  The problem was
that some user programs refused to die when the user logged out, and
instead went cracy when $DISPLAY no longer worked.  If I remember
correctly, it was typically libreoffice or firefox, and these left
behind processes would soon consume a lot of (or all) CPU and memory on
the machine, making the machine unusable for the next user.

We came up with the approach to add a background process to check
regulary for left behind processes (aka user processes for no longer
logged in users), and kill them to get rid of the problem.  It would
ignore niced processes, in the believe that left behind niced processes
were left intentionally behind and should be allowed to run.

A better approach would be to run a script when the user logged out, and
kill any stray processes at that point instead.  Unfortunately there
were no hooks available to do this.  Now, there is a hook to do so, in
/etc/X11/Xreset.d/.  Perhaps it is time to add a script in there and
retire the killer package?

Note, this is not to be taken as an argument to not fix x2go, which
really need to register its sessions in utmp/wtmp.

-- 
Happy hacking
Petter Reinholdtsen