UNIX for Dummies Questions & Answers

Experienced the same thing myself with Linux. Noticed a process by another user on a system that shouldn't have had him logged in, turned out he'd accidentally left a process spinning at 100% CPU for months and months. Nobody noticed until I'd chanced to run ps aux for completely unrelated reasons.

Excessive memory use is another ballgame entirely. So's the generation of unexpected files. You can't tune your way out of an infinite recursion.

Yes, disk space, swap space, swap rate are still challenges. I wish they would focus on making priority and sharing more intelligent in the kernel. For instance, if the system seems to be thrashing, then a "max pages owned by any process" limit could be lowered just enough to make the page generators write over their own pages while leaving a reasonable working set for the rest. If a page like a library is disowned by a process, another process may roll it back in and own it to the benefit of the heavy user, but you still do not need to choke it past that. It might be a process with a big working set, bigger than RAM, and giving it most to RAM, but not all, is good. Something like a big sort!

I wish there were separate queues for every priority/nice at every resource, so a nice -19 job can beat on disk as hard as it wants and still leave the door open for more prioritized jobs. Of course, if you want to do disk I/O on a spindle/arm that is reading for someone else, that is a modest delay on every I/O, and some devices have deep internal queues not prioritized.

For swap, you usually want the hammer to fall on a relatively recent piggy app.: less likely approved for so much swap, more relief than small proc's, but I suppose you might have to bundle proc's by terminal and then id to deal with the accidental wave of mosquitoes sort of swap problem. Maybe some sort of slow fork for groups that get too busy, not kills!