Re: [patch] CFS scheduler, -v8

Srivatsa Vaddagiri
2007-05-03T14:23:23Z

On Thu, May 03, 2007 at 10:50:15AM +0200, Ingo Molnar wrote:
> - EEVDF concentrates on real-time (SCHED_RR-alike) workloads where they
> know the length of work units

This is what I was thinking when I wrote earlier that EEVDF expects each
task will specify "length of each new request"
(http://lkml.org/lkml/2007/5/2/339).

The other observation that I have of EEVDF is that it tries to be fair
in the virtual time scale (each client will get 'wi' real units in 1
virtual unit), whereas sometimes fairness in real-time scale also matters?
For ex: a multi-media app would call scheduler fair to it, it it recvs
atleast 1 ms cpu time every 10 *real* milleseconds (frame-time). A rogue
user (or workload) that does a fork bomb may skew this fairness for that
multi-media app in real-time scale under EEVDF?

--
Regards,
vatsa