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authorLinus Torvalds <torvalds@linux-foundation.org>2020-08-03 20:28:08 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-03 20:28:08 -0700
commit04084978003c1a1810a0b1fea581078106394a32 (patch)
tree03844f5718e1200ac7b2722edfe44e5c8b15efa4 /Documentation/admin-guide
parentMerge tag 'regmap-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap (diff)
parentMerge branches 'pm-sleep', 'pm-domains', 'powercap' and 'pm-tools' (diff)
downloadlinux-dev-04084978003c1a1810a0b1fea581078106394a32.tar.xz
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Merge tag 'pm-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki: "The most significant change here is the extension of the Energy Model to cover non-CPU devices (as well as CPUs) from Lukasz Luba. There is also some new hardware support (Ice Lake server idle states table for intel_idle, Sapphire Rapids and Power Limit 4 support in the RAPL driver), some new functionality in the existing drivers (eg. a new switch to disable/enable CPU energy-efficiency optimizations in intel_pstate, delayed timers in devfreq), some assorted fixes (cpufreq core, intel_pstate, intel_idle) and cleanups (eg. cpuidle-psci, devfreq), including the elimination of W=1 build warnings from cpufreq done by Lee Jones. Specifics: - Make the Energy Model cover non-CPU devices (Lukasz Luba). - Add Ice Lake server idle states table to the intel_idle driver and eliminate a redundant static variable from it (Chen Yu, Rafael Wysocki). - Eliminate all W=1 build warnings from cpufreq (Lee Jones). - Add support for Sapphire Rapids and for Power Limit 4 to the Intel RAPL power capping driver (Sumeet Pawnikar, Zhang Rui). - Fix function name in kerneldoc comments in the idle_inject power capping driver (Yangtao Li). - Fix locking issues with cpufreq governors and drop a redundant "weak" function definition from cpufreq (Viresh Kumar). - Rearrange cpufreq to register non-modular governors at the core_initcall level and allow the default cpufreq governor to be specified in the kernel command line (Quentin Perret). - Extend, fix and clean up the intel_pstate driver (Srinivas Pandruvada, Rafael Wysocki): * Add a new sysfs attribute for disabling/enabling CPU energy-efficiency optimizations in the processor. * Make the driver avoid enabling HWP if EPP is not supported. * Allow the driver to handle numeric EPP values in the sysfs interface and fix the setting of EPP via sysfs in the active mode. * Eliminate a static checker warning and clean up a kerneldoc comment. - Clean up some variable declarations in the powernv cpufreq driver (Wei Yongjun). - Fix up the ->enter_s2idle callback definition to cover the case when it points to the same function as ->idle correctly (Neal Liu). - Rearrange and clean up the PSCI cpuidle driver (Ulf Hansson). - Make the PM core emit "changed" uevent when adding/removing the "wakeup" sysfs attribute of devices (Abhishek Pandit-Subedi). - Add a helper macro for declaring PM callbacks and use it in the MMC jz4740 driver (Paul Cercueil). - Fix white space in some places in the hibernate code and make the system-wide PM code use "const char *" where appropriate (Xiang Chen, Alexey Dobriyan). - Add one more "unsafe" helper macro to the freezer to cover the NFS use case (He Zhe). - Change the language in the generic PM domains framework to use parent/child terminology and clean up a typo and some comment fromatting in that code (Kees Cook, Geert Uytterhoeven). - Update the operating performance points OPP framework (Lukasz Luba, Andrew-sh.Cheng, Valdis Kletnieks): * Refactor dev_pm_opp_of_register_em() and update related drivers. * Add a missing function export. * Allow disabled OPPs in dev_pm_opp_get_freq(). - Update devfreq core and drivers (Chanwoo Choi, Lukasz Luba, Enric Balletbo i Serra, Dmitry Osipenko, Kieran Bingham, Marc Zyngier): * Add support for delayed timers to the devfreq core and make the Samsung exynos5422-dmc driver use it. * Unify sysfs interface to use "df-" as a prefix in instance names consistently. * Fix devfreq_summary debugfs node indentation. * Add the rockchip,pmu phandle to the rk3399_dmc driver DT bindings. * List Dmitry Osipenko as the Tegra devfreq driver maintainer. * Fix typos in the core devfreq code. - Update the pm-graph utility to version 5.7 including a number of fixes related to suspend-to-idle (Todd Brandt). - Fix coccicheck errors and warnings in the cpupower utility (Shuah Khan). - Replace HTTP links with HTTPs ones in multiple places (Alexander A. Klimov)" * tag 'pm-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (71 commits) cpuidle: ACPI: fix 'return' with no value build warning cpufreq: intel_pstate: Fix EPP setting via sysfs in active mode cpufreq: intel_pstate: Rearrange the storing of new EPP values intel_idle: Customize IceLake server support PM / devfreq: Fix the wrong end with semicolon PM / devfreq: Fix indentaion of devfreq_summary debugfs node PM / devfreq: Clean up the devfreq instance name in sysfs attr memory: samsung: exynos5422-dmc: Add module param to control IRQ mode memory: samsung: exynos5422-dmc: Adjust polling interval and uptreshold memory: samsung: exynos5422-dmc: Use delayed timer as default PM / devfreq: Add support delayed timer for polling mode dt-bindings: devfreq: rk3399_dmc: Add rockchip,pmu phandle PM / devfreq: tegra: Add Dmitry as a maintainer PM / devfreq: event: Fix trivial spelling PM / devfreq: rk3399_dmc: Fix kernel oops when rockchip,pmu is absent cpuidle: change enter_s2idle() prototype cpuidle: psci: Prevent domain idlestates until consumers are ready cpuidle: psci: Convert PM domain to platform driver cpuidle: psci: Fix error path via converting to a platform driver cpuidle: psci: Fail cpuidle registration if set OSI mode failed ...
Diffstat (limited to 'Documentation/admin-guide')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt5
-rw-r--r--Documentation/admin-guide/pm/cpufreq.rst6
-rw-r--r--Documentation/admin-guide/pm/intel_pstate.rst17
3 files changed, 24 insertions, 4 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index d35fd3ced0db..9e74ffd377f0 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -703,6 +703,11 @@
cpufreq.off=1 [CPU_FREQ]
disable the cpufreq sub-system
+ cpufreq.default_governor=
+ [CPU_FREQ] Name of the default cpufreq governor or
+ policy to use. This governor must be registered in the
+ kernel before the cpufreq driver probes.
+
cpu_init_udelay=N
[X86] Delay for N microsec between assert and de-assert
of APIC INIT to start processors. This delay occurs
diff --git a/Documentation/admin-guide/pm/cpufreq.rst b/Documentation/admin-guide/pm/cpufreq.rst
index 0c74a7784964..368e612145d2 100644
--- a/Documentation/admin-guide/pm/cpufreq.rst
+++ b/Documentation/admin-guide/pm/cpufreq.rst
@@ -147,9 +147,9 @@ CPUs in it.
The next major initialization step for a new policy object is to attach a
scaling governor to it (to begin with, that is the default scaling governor
-determined by the kernel configuration, but it may be changed later
-via ``sysfs``). First, a pointer to the new policy object is passed to the
-governor's ``->init()`` callback which is expected to initialize all of the
+determined by the kernel command line or configuration, but it may be changed
+later via ``sysfs``). First, a pointer to the new policy object is passed to
+the governor's ``->init()`` callback which is expected to initialize all of the
data structures necessary to handle the given policy and, possibly, to add
a governor ``sysfs`` interface to it. Next, the governor is started by
invoking its ``->start()`` callback.
diff --git a/Documentation/admin-guide/pm/intel_pstate.rst b/Documentation/admin-guide/pm/intel_pstate.rst
index 39d80bc29ccd..40d481cca368 100644
--- a/Documentation/admin-guide/pm/intel_pstate.rst
+++ b/Documentation/admin-guide/pm/intel_pstate.rst
@@ -431,6 +431,17 @@ argument is passed to the kernel in the command line.
supported in the current configuration, writes to this attribute will
fail with an appropriate error.
+``energy_efficiency``
+ This attribute is only present on platforms, which have CPUs matching
+ Kaby Lake or Coffee Lake desktop CPU model. By default
+ energy efficiency optimizations are disabled on these CPU models in HWP
+ mode by this driver. Enabling energy efficiency may limit maximum
+ operating frequency in both HWP and non HWP mode. In non HWP mode,
+ optimizations are done only in the turbo frequency range. In HWP mode,
+ optimizations are done in the entire frequency range. Setting this
+ attribute to "1" enables energy efficiency optimizations and setting
+ to "0" disables energy efficiency optimizations.
+
Interpretation of Policy Attributes
-----------------------------------
@@ -554,7 +565,11 @@ somewhere between the two extremes:
Strings written to the ``energy_performance_preference`` attribute are
internally translated to integer values written to the processor's
Energy-Performance Preference (EPP) knob (if supported) or its
-Energy-Performance Bias (EPB) knob.
+Energy-Performance Bias (EPB) knob. It is also possible to write a positive
+integer value between 0 to 255, if the EPP feature is present. If the EPP
+feature is not present, writing integer value to this attribute is not
+supported. In this case, user can use
+ "/sys/devices/system/cpu/cpu*/power/energy_perf_bias" interface.
[Note that tasks may by migrated from one CPU to another by the scheduler's
load-balancing algorithm and if different energy vs performance hints are