Re: [PATCH v7 03/15] sched/core: uclamp: Add system default clamps

Peter Zijlstra
2019-03-13T19:58:50Z

On Wed, Mar 13, 2019 at 05:09:40PM +0000, Patrick Bellasi wrote:
> On 13-Mar 15:32, Peter Zijlstra wrote:

> > I still think that this effective thing is backwards.

> With respect to the previous v6, I've now moved this concept to the
> patch where we actually use it for the first time.

> The "effective" values allows to efficiently enforce the most
> restrictive clamp value for a task at enqueue time by:
> - not loosing track of the original request
> - don't caring about updating non runnable tasks

My point is that you already had an effective value; namely p->uclamp[],
since patch 1.

This patch then changes that into something else, instead of adding
p->uclamp_orig[], and concequently has to update all sites that
previously used p->uclamp[], which is a lot of pointless churn.