| From | Lukasz Majewski <> | Subject | [PATCH v4 0/7] cpufreq:boost: CPU Boost mode support | Date | Wed, 19 Jun 2013 19:12:41 +0200 |
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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
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(-)
-- 1.7.10.4
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