path: root/Documentation/scheduler
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authorLinus Torvalds <>2020-12-15 16:30:31 -0800
committerLinus Torvalds <>2020-12-15 16:30:31 -0800
commitb4ec805464a4a0299216a003278351d0b4806450 (patch)
tree1a864de7b10116bbf6cf16c9095a19921d7ed7eb /Documentation/scheduler
parentb109bc72295363fb746bc42bdd777f7a8abb177b (diff)
parentb3fac817830306328d5195e7f4fb332277f3b146 (diff)
Merge tag 'pm-5.11-rc1' of git://
Pull power management updates from Rafael Wysocki: "These update cpufreq (core and drivers), cpuidle (polling state implementation and the PSCI driver), the OPP (operating performance points) framework, devfreq (core and drivers), the power capping RAPL (Running Average Power Limit) driver, the Energy Model support, the generic power domains (genpd) framework, the ACPI device power management, the core system-wide suspend code and power management utilities. Specifics: - Use local_clock() instead of jiffies in the cpufreq statistics to improve accuracy (Viresh Kumar). - Fix up OPP usage in the cpufreq-dt and qcom-cpufreq-nvmem cpufreq drivers (Viresh Kumar). - Clean up the cpufreq core, the intel_pstate driver and the schedutil cpufreq governor (Rafael Wysocki). - Fix up error code paths in the sti-cpufreq and mediatek cpufreq drivers (Yangtao Li, Qinglang Miao). - Fix cpufreq_online() to return error codes instead of success (0) in all cases when it fails (Wang ShaoBo). - Add mt8167 support to the mediatek cpufreq driver and blacklist mt8516 in the cpufreq-dt-platdev driver (Fabien Parent). - Modify the tegra194 cpufreq driver to always return values from the frequency table as the current frequency and clean up that driver (Sumit Gupta, Jon Hunter). - Modify the arm_scmi cpufreq driver to allow it to discover the power scale present in the performance protocol and provide this information to the Energy Model (Lukasz Luba). - Add missing MODULE_DEVICE_TABLE to several cpufreq drivers (Pali Rohár). - Clean up the CPPC cpufreq driver (Ionela Voinescu). - Fix NVMEM_IMX_OCOTP dependency in the imx cpufreq driver (Arnd Bergmann). - Rework the poling interval selection for the polling state in cpuidle (Mel Gorman). - Enable suspend-to-idle for PSCI OSI mode in the PSCI cpuidle driver (Ulf Hansson). - Modify the OPP framework to support empty (node-less) OPP tables in DT for passing dependency information (Nicola Mazzucato). - Fix potential lockdep issue in the OPP core and clean up the OPP core (Viresh Kumar). - Modify dev_pm_opp_put_regulators() to accept a NULL argument and update its users accordingly (Viresh Kumar). - Add frequency changes tracepoint to devfreq (Matthias Kaehlcke). - Add support for governor feature flags to devfreq, make devfreq sysfs file permissions depend on the governor and clean up the devfreq core (Chanwoo Choi). - Clean up the tegra20 devfreq driver and deprecate it to allow another driver based on EMC_STAT to be used instead of it (Dmitry Osipenko). - Add interconnect support to the tegra30 devfreq driver, allow it to take the interconnect and OPP information from DT and clean it up (Dmitry Osipenko). - Add interconnect support to the exynos-bus devfreq driver along with interconnect properties documentation (Sylwester Nawrocki). - Add suport for AMD Fam17h and Fam19h processors to the RAPL power capping driver (Victor Ding, Kim Phillips). - Fix handling of overly long constraint names in the powercap framework (Lukasz Luba). - Fix the wakeup configuration handling for bridges in the ACPI device power management core (Rafael Wysocki). - Add support for using an abstract scale for power units in the Energy Model (EM) and document it (Lukasz Luba). - Add em_cpu_energy() micro-optimization to the EM (Pavankumar Kondeti). - Modify the generic power domains (genpd) framwework to support suspend-to-idle (Ulf Hansson). - Fix creation of debugfs nodes in genpd (Thierry Strudel). - Clean up genpd (Lina Iyer). - Clean up the core system-wide suspend code and make it print driver flags for devices with debug enabled (Alex Shi, Patrice Chotard, Chen Yu). - Modify the ACPI system reboot code to make it prepare for system power off to avoid confusing the platform firmware (Kai-Heng Feng). - Update the pm-graph (multiple changes, mostly usability-related) and cpupower (online and offline CPU information support) PM utilities (Todd Brandt, Brahadambal Srinivasan)" * tag 'pm-5.11-rc1' of git:// (86 commits) cpufreq: Fix cpufreq_online() return value on errors cpufreq: Fix up several kerneldoc comments cpufreq: stats: Use local_clock() instead of jiffies cpufreq: schedutil: Simplify sugov_update_next_freq() cpufreq: intel_pstate: Simplify intel_cpufreq_update_pstate() PM: domains: create debugfs nodes when adding power domains opp: of: Allow empty opp-table with opp-shared dt-bindings: opp: Allow empty OPP tables media: venus: dev_pm_opp_put_*() accepts NULL argument drm/panfrost: dev_pm_opp_put_*() accepts NULL argument drm/lima: dev_pm_opp_put_*() accepts NULL argument PM / devfreq: exynos: dev_pm_opp_put_*() accepts NULL argument cpufreq: qcom-cpufreq-nvmem: dev_pm_opp_put_*() accepts NULL argument cpufreq: dt: dev_pm_opp_put_regulators() accepts NULL argument opp: Allow dev_pm_opp_put_*() APIs to accept NULL opp_table opp: Don't create an OPP table from dev_pm_opp_get_opp_table() cpufreq: dt: Don't (ab)use dev_pm_opp_get_opp_table() to create OPP table opp: Reduce the size of critical section in _opp_kref_release() PM / EM: Micro optimization in em_cpu_energy cpufreq: arm_scmi: Discover the power scale in performance protocol ...
Diffstat (limited to 'Documentation/scheduler')
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/scheduler/sched-energy.rst b/Documentation/scheduler/sched-energy.rst
index 001e09c95e1d..afe02d394402 100644
--- a/Documentation/scheduler/sched-energy.rst
+++ b/Documentation/scheduler/sched-energy.rst
@@ -350,6 +350,11 @@ independent EM framework in Documentation/power/energy-model.rst.
Please also note that the scheduling domains need to be re-built after the
EM has been registered in order to start EAS.
+EAS uses the EM to make a forecasting decision on energy usage and thus it is
+more focused on the difference when checking possible options for task
+placement. For EAS it doesn't matter whether the EM power values are expressed
+in milli-Watts or in an 'abstract scale'.
6.3 - Energy Model complexity