Messages in this thread | | | Date | Thu, 14 Mar 2019 20:18:49 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v7 01/15] sched/core: uclamp: Add CPU's clamp buckets refcounting |
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On Thu, Mar 14, 2019 at 03:07:53PM +0000, Patrick Bellasi wrote: > On 14-Mar 14:32, Peter Zijlstra wrote: > > 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. > > your "arm version" is worst then x86, or "your version" is worse? > > IOW, should I keep the code as the original? Do you prefer your > version? Or... we don't really care...
Yeah, keep the original, it didn't matter on x86 and arm regressed with my version.
> > It does what I expected with -Os, but as Rutland said the other day, > > that stands for Optimize for Sadness. > > Yes, I guess we cannot optimize for all flags... however, just let me > know what you prefer and I'll put that version in ;)
Yeah, don't bother optimizing for -Os, it generally creates atrocious crap, hence Rutland calling it 'Optimize for Sadness'.
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