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

From: Rafael J. Wysocki
Date: Wed Oct 04 2017 - 08:28:12 EST


On Wed, Oct 4, 2017 at 10:41 AM, Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> 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?

Dietmar asked me and I can handle it it that's not an issue.

Thanks,
Rafael