Re: [PATCH 0/2] cpufreq: Upstream Android's Interactive governor

From: Rafael J. Wysocki
Date: Fri May 20 2016 - 07:26:59 EST


On Fri, May 20, 2016 at 8:39 AM, Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote:
> Hi Rafael et. al.,
>
> We had some discussions [1] last week on the PM mailing about
> upstreaming the cpufreq governor most widely used on Andoid Mobile
> phones and tablets: Interactive governor. People (including Rafael)
> mostly agreed that we better get it upstreamed and here is an attempt to
> upstream most of it (idle notifiers aren't included in this series).
>
> I picked the latest code spread over 70-80 patches from [2]. The
> unmodified code, based over mainline is pushed [4] for reference.
>
> I have updated the governor to align it with the current practices
> followed with mainline governors, like using utilization hooks from the
> scheduler and handling kobject (for governor's sysfs directory) in a
> race free manner. And of course this included general cleanup of the
> governor as well. This version is pushed here [3] for testing.
>
> The Android version of interactive governor also uses idle EXIT
> notifiers, but that code isn't part of this series and will be sent
> separately later. For people interested in looking at that, those are 3
> minor patches on top of this series and are pushed here [5].
>
> I haven't changed the core logic of the governor intentionally, as that
> rather requires more in-depth knowledge of the use case for which the
> optimizations have been done. So, we should do any such thing later on
> with new patches, so that people can find things easily.
>
> I also haven't tried to change the userspace interface as that may have
> broken the userspace that already exists and uses this governor.
>
> This has been lightly tested on my Exynos board (dual ARM A15), where
> the governor gets inserted/removed multiple times, the sysfs files are
> all functional. The frequency gets changed with load, etc.
>
> This series is based of pm/bleeding-edge branch + few patches from
> Rafael [6] & [7] and few minor cleanups from me [8].

OK, thanks!

This may take some time to review, though.