Re: [RFC PATCH 09/13] sched/fair: core wide vruntime comparison

[Aaron Lu]

On Wed, Apr 15, 2020 at 05:24:30PM -0400, Vineeth Remanan Pillai wrote:
> > > > You forgot the time complexity analysis.
> > >
> > > This is a mistake and the adjust should be needed only once when core
> > > scheduling is initially enabled. It is an initialization thing and there
> > > is no reason to do it in every invocation of coresched_adjust_vruntime().
> >
> > Correction...
> > I meant there is no need to call coresched_adjust_vruntime() in every
> > invocation of update_core_cfs_rq_min_vruntime().
> 
> Due to the checks in place, update_core_cfs_rq_min_vruntime should
> not be calling coresched_adjust_vruntime more than once between a
> coresched enable/disable. Once the min_vruntime is adjusted, we depend
> only on rq->core and the other sibling's min_vruntime will not grow
> until coresched disable.

OK, but I prefer to make it clear that this is an initialization only
stuff. Below is what I cooked, I also enhanced the changelog while at
it.