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

Viresh Kumar
2013-08-19T06:38:26Z

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,

I haven't found time yet to go through this series.. I want to do a deep/careful
review this time as these are almost the final patches.

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

--
viresh