From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lukasz Majewski Subject: Re: [PATCH v4 0/7] cpufreq:boost: CPU Boost mode support Date: Wed, 26 Jun 2013 09:48:11 +0200 Message-ID: <20130626094811.1986e875@amdc308.digital.local> References: <1370502472-7249-1-git-send-email-l.majewski@samsung.com> <1371661969-7660-1-git-send-email-l.majewski@samsung.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <1371661969-7660-1-git-send-email-l.majewski@samsung.com> Sender: cpufreq-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Viresh Kumar Cc: Lukasz Majewski , "Rafael J. Wysocky" , "cpufreq@vger.kernel.org" , Linux PM list , Vincent Guittot , Jonghwa Lee , Myungjoo Ham , linux-kernel , Lukasz Majewski , Andre Przywara , Daniel Lezcano , Kukjin Kim , Zhang Rui , Eduardo Valentin 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