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