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This week in the scheduling discussion

Posted Apr 26, 2007 9:24 UTC (Thu) by nowster (subscriber, #67)
In reply to: This week in the scheduling discussion by nix
Parent article: This week in the scheduling discussion

This time-as-money analogy can be extended further. I can imagine a system which has a sort of futures market in runtime...

Could a "rogue trader" break the bank? :-)

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Posted Apr 27, 2007 14:11 UTC (Fri) by nix (subscriber, #2304) [Link]

I don't see how (assuming `breaking the bank' to equate to a DoS attack or something like that). If a process demands heaps of time in the future and doesn't use it, it'll sacrifice all its current time and end up with nothing (i.e. an idling system or other processes using the time instead). If it demands heaps of time and other things do as well, then it won't get that much time. No problem in either case.

HOWTO deny service

Posted Apr 30, 2007 5:55 UTC (Mon) by kbob (guest, #1770) [Link]

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.