Re: CFS scheduler unfairly prefers pinned tasks

[paul . szabo]

Dear Mike,

>>> I see a fairness issue ... but one opposite to your complaint.
>> Why is that opposite? ...
>
> Well, not exactly opposite, only opposite in that the one pert task also
> receives MORE than it's fair share when unpinned.  Two 100$ hogs sharing
> one CPU should each get 50% of that CPU. ...

But you are using CGROUPs, grouping all oinks into one group, and the
one pert into another: requesting each group to get same total CPU.
Since pert has one process only, the most he can get is 100% (not 400%),
and it is quite OK for the oinks together to get 700%.

> IFF ... massively parallel and synchronized ...

You would be making the assumption that you had the machine to yourself:
might be the wrong thing to assume.

>> Good to see that you agree ...
> Weeell, we've disagreed on pretty much everything ...

Sorry I disagree: we do agree on the essence. :-)

Cheers, Paul

Paul Szabo   psz@xxxxxxxxxxxxxxxxx   http://www.maths.usyd.edu.au/u/psz/
School of Mathematics and Statistics   University of Sydney    Australia
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