HOWTO deny service

Posted Apr 30, 2007 5:55 UTC (Mon) by kbob (guest, #1770)
In reply to: This week in the scheduling discussion by nix
Parent article: This week in the scheduling discussion

Consider an isochronous process like a real time audio processor.
It needs a time chunk every N milliseconds, so that's what it bids for.

A malicious process could outbid the audio process for a smaller timeslice
right when the audio app needs it. Then it could busy-loop for just
long enough that the audio app won't be able to finish on time.
Denial of Service.

On a longer time scale, the isochronous app might be a machine vision
system, a CD burner, or a monthly accounting report.

The malicious process wouldn't intentionally be malicious, of course.
It would just have an unfortunate self-scheduling policy.