Re: [RFCv7 PATCH 01/10] sched: Compute cpu capacity available at current frequency

From: Peter Zijlstra
Date: Fri Feb 26 2016 - 04:15:06 EST

On Fri, Feb 26, 2016 at 02:37:19AM +0100, Rafael J. Wysocki wrote:

> That's all correct, but my question should rather be: is arch the right
> granularity?
> In theory, there may be ARM64-based platforms using ACPI and behaving
> like x86 in that respect in the future.

Ah, so I started these hooks way before the cpufreq/cpuidle etc.
integration push.

Maybe we should look at something like that, but performance is really
critical, you most definitely do not want 3 indirections just because
abstract framework crap, that's measurable overhead on these callsites.

Hence the current inline with constant value or single function call.
And if archs would want a selector, I would recommend boot time call
instruction rewrites a-la alternatives/paravirt.