Re: [PATCH v7 0/7] cpufreq:boost: CPU Boost mode support

Lukasz Majewski
2013-08-19T06:50:37Z

On Mon, 19 Aug 2013 12:08:26 +0530 Viresh Kumar viresh.kumar@linaro.org
wrote,
> On 13 August 2013 15:38, Lukasz Majewski <l.majewski@samsung.com>
> wrote:
> > This patch series introduces support for CPU overclocking technique
> > called Boost.
> >
> > It is a follow up of a LAB governor proposal. Boost is a LAB
> > component:
> > http://thread.gmane.org/gmane.linux.kernel/1484746/match=cpufreq
> >
> > Boost unifies hardware based solution (e.g. Intel Nehalem) with
> > software oriented one (like the one done at Exynos).
> > For this reason cpufreq/freq_table code has been reorganized to
> > include common code.
> >
> > Important design decisions:
> > - Boost related code is compiled-in unconditionally to cpufreq core
> > and disabled by default. The cpufreq_driver is responsibile for
> > setting boost_supported flag and providing set_boost callback(if HW
> > support is needed). For software managed boost, special Kconfig
> > flag - CONFIG_CPU_FREQ_BOOST_SW has been defined. It will be
> > selected only when a target platform has thermal framework properly
> > configured.
> >
> > - struct cpufreq_driver has been extended with boost related fields:
> > -- boost_supported - when driver supports boosting
> > -- boost_enabled - boost state
> > -- set_boost - callback to function, which is necessary to
> > enable/disable boost
> >
> > - Boost sysfs attribute (/sys/devices/system/cpu/cpufreq/boost) is
> > visible _only_ when cpufreq driver supports Boost.
> >
> > - No special spin_lock for Boost was created. The one from cpufreq
> > core was reused.
> >
> > - The Boost code doesn't rely on any policy. When boost state is
> > changed, then the policy list is iterated and proper adjustements
> > are done.
> >
> > - To improve safety level, the thermal framework is also extended
> > to disable software boosting, when thermal trip point is reached.
> > Then it starts monitoring target temperature to evaluate if boost
> > can be enabled again. This emulates behaviour similar to HW managed
> > boost (like x86)
> >
> > Tested at HW:
> > Exynos 4412 3.11-rc4 Linux
> > Intel Core i7-3770 3.11-rc4 Linux
> >
> > Above patches were posted on top of linux_pm/linux-next with
> > following patches applied:
> >
> > cpufreq: exynos5440: Fix to skip when new frequency same as current
> > cpufreq: fix EXYNOS drivers selection
> >
> > Lukasz Majewski (7):
> > cpufreq: Add boost frequency support in core
> > cpufreq:acpi:x86: Adjust the acpi-cpufreq.c code to work with
> > common boost solution
> > thermal:boost: Automatic enable/disable of BOOST feature
> > cpufreq:boost:Kconfig: Provide support for software managed BOOST
> > cpufreq:exynos:Extend Exynos cpufreq driver to support boost
> > framework
> > Documentation:cpufreq:boost: Update BOOST documentation
> > cpufreq:exynos4x12: Change L0 driver data to CPUFREQ_BOOST_FREQ
>
> Hi Lukasz,
>

Hi Viresh,

> I haven't found time yet to go through this series..

I've just started wondering if I had send those patches correctly :-).

> I want to do a
> deep/careful review this time as these are almost the final patches.

Ok.

>
> Will try to get over them by the end of this week..

Ok, I understand.

>
> --
> viresh
> --
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--
Best regards,

Lukasz Majewski

Samsung R&D Institute Poland (SRPOL) | Linux Platform Group