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    SubjectRe: [PATCH v4 0/7] cpufreq:boost: CPU Boost mode support
    Hi Viresh,

    > 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 and disabled by
    > default The cpufreq_driver is responsibile for setting
    > boost_supported flag and providing enable_boost callback(if HW
    > support is needed)
    >
    > - struct cpufreq_driver has been extended with boost related fields:
    > -- boost_supported - when driver supports boosting
    > -- enable_boost - callback to function, which is necessary to
    > enable boost in the processor (like it is done at Intel)
    >
    > - Boost sysfs attribute (/sys/devices/system/cpu/cpufreq/boost) is
    > always provided.
    > It will be read only, until either cpufreq_driver defines
    > boost_supported flag or device tree's cpufreq "boost_mode" attribute
    > is defined. It is consistent with legacy acpi API.
    >
    > - No special spin_lock for Boost was created. The one from cpufreq
    > core was reused.
    >
    > - All available policies are now stored in a list.
    >
    > - 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.
    >
    > - Number of busy cpus (with load > 90%) is calculated and exported as
    > a global sysfs attribute.
    >
    > - The SW based boost can be only enabled when up to one core is
    > regarded as a "busy" one. For safety reasons boost is disabled when
    > more cores comes into play.
    >
    > - To improve safety level, the thermal framework is also extended to
    > disable software boosting, when thermal trip point is reached.
    >
    > New patches for v4:
    > cpufreq: Store cpufreq policies in a list
    > cpufreq: Calculate number of busy CPUs
    > cpufreq: Enable software boost only when up to one busy core is
    > running thermal:boost: Disable boost when trip point is reached
    >
    > Tested at: HW:
    > Exynos 4412 3.10 linux
    > Exynos 4210 3.10 linux
    > Compile tested x86_64 defconfig (acpi) - help with HW (Intel Nehalem)
    > test needed
    >

    If this is not a problem, I'd like to kindly ask You to review those
    patches.

    Rafael has expressed his opinion about "boost" attribute clearly at the
    other mail (as a response to v4 patches):
    "Simple: Export it only when supported."

    Despite the change about the "boost" attribute visibility there were
    many other changes, which deserve maintainer's look.



    >
    > Lukasz Majewski (7):
    > cpufreq: Store cpufreq policies in a list
    > cpufreq: Add boost frequency support in core
    > cpufreq:acpi:x86: Adjust the acpi-cpufreq.c code to work with common
    > boost solution
    > cpufreq:exynos:Extend Exynos cpufreq driver to support boost
    > framework
    > cpufreq: Calculate number of busy CPUs
    > cpufreq: Enable software boost only when up to one busy core is
    > running
    > thermal:boost: Disable boost when trip point is reached
    >
    > drivers/cpufreq/acpi-cpufreq.c | 61 ++++++-----------
    > drivers/cpufreq/cpufreq.c | 132
    > ++++++++++++++++++++++++++++++++++++
    > drivers/cpufreq/cpufreq_governor.c | 4 ++
    > drivers/cpufreq/exynos-cpufreq.c | 4 ++
    > drivers/cpufreq/freq_table.c | 43 ++++++++++--
    > drivers/thermal/cpu_cooling.c | 3 +
    > include/linux/cpufreq.h | 15 ++++ 7 files changed, 215
    > insertions(+), 47 deletions(-)
    >



    --
    Best regards,

    Lukasz Majewski

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


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