Re: [PATCH v7 01/15] sched/core: uclamp: Add CPU's clamp buckets refcounting

From: Peter Zijlstra
Date: Thu Mar 14 2019 - 09:32:19 EST


On Thu, Mar 14, 2019 at 12:13:15PM +0000, Patrick Bellasi wrote:
> > I'd be most impressed if they pull this off. Check the generated code
> > and see I suppose :-)
>
> On x86 the code generated looks exactly the same:
>
> https://godbolt.org/z/PjmA7k

Argh, they do mult by inverse to avoid the division, and can do this
because its a constant.

And then yes, your arm version looks worse.

It does what I expected with -Os, but as Rutland said the other day,
that stands for Optimize for Sadness.