Re: [PATCH 6/9] sched/fair: Removed unsued cfs_rq.h_nr_delayed

[Vincent Guittot]

On Thu, 28 Nov 2024 at 11:15, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> On Thu, Nov 28, 2024 at 11:03:48AM +0100, Peter Zijlstra wrote:
> > On Thu, Nov 28, 2024 at 10:27:47AM +0100, Vincent Guittot wrote:
> > > h_nr_delayed is not used anymore. We now have
> > > - h_nr_running which tracks tasks ready to run
> > > - h_nr_enqueued which tracks enqueued tasks either ready to run or delayed
> > >   dequeue
> >
> > Oh, now I see where you're going.
> >
> > Let me read the lot again, because this sure as hell was a confusing
> > swizzle.
>
> So the first patch adds h_nr_delayed.
>
> Then confusion

I started from your patch that adds h_nr_delayed and added on top the
steps to move to h_nr_enqueued and h_nr_running to make it easier to
understand the changes

>
> Then we end up with:
>
>  h_nr_enqueued = h_nr_running + h_nr_delayed
>
> Where h_nr_enqueued is part of rq->nr_running (and somewhere along the
> way you rename and remove some idle numbers).
>
> Can't we structure it like:
>
>   - add h_nr_delayed
>   - rename h_nr_running to h_nr_queued
>   - add h_nr_runnable = h_nr_queued - h_nr_delayed
>   - use h_hr_runnable
>   - remove h_nr_delayed
>
>   - clean up idle muck
>

I can reorder the patches following the above

>
> And I'm assuming this ordering is because people want h_nr_delayed
> backported. Because the even more sensible order would be something
> like:
>
>  - rename h_nr_running into h_nr_queued
>  - add h_nr_runnable (being h_nr_queued - h_nr_delayed, without ever
>    having had h_nr_delayed).
>  - use h_nr_runnable
>
>  - clean up idle muck
>
>