Re: [PATCH v5 00/10] arm, arm64, cpufreq: frequency- and cpu-invariant accounting support for task scheduler

From: Greg Kroah-Hartman
Date: Wed Oct 04 2017 - 04:41:12 EST


On Tue, Sep 26, 2017 at 05:41:05PM +0100, Dietmar Eggemann wrote:
> For a more accurate (i.e. frequency- and cpu-invariant) accounting
> the task scheduler needs a frequency-scaling and on a heterogeneous
> system a cpu-scaling correction factor.
>
> This patch-set implements a Frequency Invariance Engine (FIE)
> based on the ratio of current frequency and maximum supported frequency
> (topology_get_freq_scale()) in the arch topology driver (arm, arm64) to
> provide such a frequency-scaling correction factor.
> This is a solution to get frequency-invariant accounting support for
> platforms without hardware-based performance tracking.
>
> The Cpu Invariance Engine (CIE) (topology_get_cpu_scale()) providing a
> cpu-scaling correction factor was already introduced by the "Fix issues
> and factorize arm/arm64 capacity information code" patch-set [1] which
> went into v4.13.
>
> This patch-set also enables the frequency- and cpu-invariant accounting
> support. Enabling here means to associate (wire) the task scheduler
> function name arch_scale_freq_capacity and arch_scale_cpu_capacity with
> the FIE and CIE function names from drivers/base/arch_topology.c. This
> replaces the scheduler's default FIE and CIE in kernel/sched/sched.h.
>
> v4: review results:
>
> There were no further comments during the v4 [2] review.

This patchset crosses a bunch of different subsystems, who do you
want/expect to be taking this through their tree?

thanks,

greg k-h