Re: [PATCH 6/6] sched: final power vs capacity cleanup

From: Nicolas Pitre
Date: Thu May 15 2014 - 12:12:48 EST


On Thu, 15 May 2014, Peter Zijlstra wrote:

> On Wed, May 14, 2014 at 04:57:10PM -0400, Nicolas Pitre wrote:
> > It is better not to think about compute capacity as being equivalent to
> > "CPU power". The upcoming "power aware" scheduler may create confusion
> > with the notion of energy consumption if "power" is used too liberally.
> >
> > This contains the architecture visible changes. Incidentally, only ARM
> > takes advantage of the available pow^H^H^Hcapacity scaling hooks and
> > therefore those changes outside kernel/sched/ are confined to one ARM
> > specific file. The default arch_scale_smt_power() hook is not overridden
> > by anyone.
> >
> > Replacements are as follows:
> >
> > arch_scale_freq_power --> arch_scale_freq_capacity
> > arch_scale_smt_power --> arch_scale_smt_capacity
> > SCHED_POWER_SCALE --> SCHED_CAPA_SCALE
> > SCHED_POWER_SHIFT --> SCHED_POWER_SHIFT
>
> The patch seems to actually make that CAPA_SHIFT

Huh... right, of course.

> > The local usage of "power" in arch/arm/kernel/topology.c is also changed
> > to "capacity" as appropriate.
>
> For some reason every time I read: 'capa' I think of some south American
> monster -- http://en.wikipedia.org/wiki/Chupacabra, I'm not at all sure
> why my brain links them.

:-)

capa != paca

I chose that not to make this much longer than "POWER", and since there
are already "LOAD" related constants, I thought there was some symetry
to another 4-letter identifier. Do you have other suggestions?


Nicolas
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