Hi Rui,
is it possible to merge these patches? They are acked-by since May. Thanks -- Daniel On 01/08/2019 14:46, Quentin Perret wrote: > Changes in v6 > ************* > - Added Daniel's and Viresh's Acked-by to all patches > > Changes in v5: > ************** > - Changed patch 02 to guard IPA-specific code in cpu_cooling.c with > appropriate ifdefery (Daniel) > - Rebased on 5.2-rc2 > > Changes in v4: > ************** > - Added Viresh's Acked-by to all 3 patches > - Improved commit message of patch 3/3 to explain how it has no > functional impact on existing users (Eduardo) > > Changes in v3: > ************** > - Changed warning message for unordered tables to something more > explicit (Viresh) > - Changed WARN() into a pr_err() for consistency > > Changes in v2: > ************** > - Fixed patch 01/03 to actually enable CONFIG_ENERGY_MODEL > - Added "depends on ENERGY_MODEL" to IPA (Daniel) > - Added check to bail out if the freq table is unsorted (Viresh) > > Cover letter: > ************* > > The Intelligent Power Allocator (IPA) thermal governor uses an Energy > Model (or EM) of the CPUs to re-distribute the power budget. To do so, > it builds a table of <frequency, power> tuples where the power values > are computed using the 'dynamic-power-coefficient' DT property. All of > this is done in and only for the thermal subsystem, and more > specifically for CPUs -- the power of other types of devices is obtained > differently. > > Recently, the CPU scheduler has seen the introduction of Energy Aware > Scheduling (EAS) patches, which also rely on an EM of the CPUs. This EM, > however, is managed by an independent framework, called PM_EM, aimed to > be used by all kernel subsystems interested in the power consumed by > CPUs, and not only the scheduler. > > This patch series follows this logic and removes the (now redundant) > thermal-specific EM computation code to migrate IPA to use PM_EM > instead. > > Doing so should have no visible functional impact for existing users of > IPA since: > > - during the 5.1 development cycle, a series of patches [1] introduced > in PM_OPP some infrastructure (dev_pm_opp_of_register_em()) enabling > the registration of EMs in PM_EM using the DT property used by IPA; > > - the existing upstream cpufreq drivers marked with the > 'CPUFREQ_IS_COOLING_DEV' flag all call dev_pm_opp_of_register_em(), > which means they all support PM_EM (the only two exceptions are > qoriq-cpufreq which doesn't in fact use an EM and scmi-cpufreq which > already supports PM_EM without using the PM_OPP infrastructurei > because it read power costs directly from firmware); > > So, migrating IPA to using PM_EM should effectively be just plumbing > since for the existing IPA users the PM_EM tables will contain the > exact same power values that IPA used to compute on its own until now. > The only new dependency is to compile in CONFIG_ENERGY_MODEL. > > Why is this migration still a good thing ? For three main reasons. > > 1. it removes redundant code; > > 2. it introduces an abstraction layer between IPA and the EM > computation. PM_EM offers to EAS and IPA (and potentially other > clients) standardized EM tables and hides 'how' these tables have > been obtained. PM_EM as of now supports power values either coming > from the 'dynamic-power-coefficient' DT property or obtained > directly from firmware using SCMI. The latter is a new feature for > IPA and that comes 'for free' with the migration. This will also be > true in the future every time PM_EM gets support for other ways of > loading the EM. Moreover, PM_EM is documented and has a debugfs > interface which should help adding support for new platforms. > > 3. it builds a consistent view of the EM of CPUs across kernel > subsystems, which is a pre-requisite for any kind of future work > aiming at a smarter power allocation using scheduler knowledge about > the system for example. > > [1] > https://lore.kernel.org/lkml/[email protected]/ > > > Quentin Perret (3): > arm64: defconfig: Enable CONFIG_ENERGY_MODEL > thermal: cpu_cooling: Make the power-related code depend on IPA > thermal: cpu_cooling: Migrate to using the EM framework > > arch/arm64/configs/defconfig | 1 + > drivers/thermal/Kconfig | 1 + > drivers/thermal/cpu_cooling.c | 428 ++++++++++++++-------------------- > 3 files changed, 178 insertions(+), 252 deletions(-) > -- <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | <http://twitter.com/#!/linaroorg> Twitter | <http://www.linaro.org/linaro-blog/> Blog
