Re: [Announce] [patch] Modular Scheduler Core and Completely Fair Scheduler [CFS]

Davide Libenzi
2007-04-19T15:44:03Z

On Thu, 19 Apr 2007, Ingo Molnar wrote:

> i disagree that the user 'would expect' this. Some users might. Others
> would say: 'my 10-thread rendering engine is more important than a
> 1-thread job because it's using 10 threads for a reason'. And the CFS
> feedback so far strengthens this point: the default behavior of treating
> the thread as a single scheduling (and CPU time accounting) unit works
> pretty well on the desktop.
>
> think about it in another, 'kernel policy' way as well: we'd like to
> _encourage_ more parallel user applications. Hurting them by accounting
> all threads together sends the exact opposite message.

There are counter argouments too. Like, not every user knows if a certain
process is MT or not. I agree though that doing accounting and fairness at
a depth lower then USER is messy, and not only for performance.

- Davide