Re: Question about group scheduler cpu shares

From: Mike Galbraith
Date: Thu Jul 21 2016 - 22:51:36 EST


On Thu, 2016-07-21 at 18:18 -0700, Gaurav Poothia wrote:

> > ROOT
> > >
> > + -Group1(3072)
> > > |
> > > +- A(2048)
> > > |
> > > +- B(1024)
> > >
> > +- Group2(2048)
> > |
> > +-C(1024)
> > |
> > +-D(1024)
> >

> > Say I add a task E to Group1's task list (note that is an interior aka
> > non-leaf node)
> > How does the CPU split change between A, B and E.
> > AFAICT there is no cgroup cpu subsystem knob to weight tasks on an
> > interior node against the tasks in that node's children

A, B and E are all entities with a weight, so just plug E into your
graph. Its weight is determined by nice level, which is what cgroups
should have done instead of inventing shares IMHO. 1024 == nice(0).

-Mike