Re: [rfc patch] sched/fair: Use instantaneous load for fork/exec balancing

From: Mike Galbraith
Date: Wed Jun 15 2016 - 12:03:38 EST


On Wed, 2016-06-15 at 16:32 +0100, Dietmar Eggemann wrote:

> > In general, the fuzz helps us to not be so spastic. I'm not sure that
> > we really really need to care all that much, because I strongly suspect
> > that it's only gonna make any difference at all in corner cases, but
> > there are real world cases that matter. I know for fact that schbench
> > (facebook) which is at least based on a real world load fails early due
> > to us stacking tasks due to that fuzzy view of reality. In that case,
> > it's because the fuzz consists of a high amplitude aging sawtooth..
>
> ... only for fork/exec?

No. Identical workers had longish work/sleep cycle, aging resulted in
weights that ranged from roughly 300-700(ish), depending on when you
peeked at them.

-Mike