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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-07 04:40:31 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-07 04:40:31 +0200 |
commit | 8f5e823f9131a430b12f73e9436d7486e20c16f5 (patch) | |
tree | ec3f03c236182d113dd71b1b7b59be73e54ebab1 /Documentation/admin-guide/pm/cpufreq.rst | |
parent | Merge tag 'acpi-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/raf... (diff) | |
parent | Merge branches 'pm-devfreq' and 'pm-domains' (diff) | |
download | linux-8f5e823f9131a430b12f73e9436d7486e20c16f5.tar.xz linux-8f5e823f9131a430b12f73e9436d7486e20c16f5.zip |
Merge tag 'pm-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki:
"These fix the (Intel-specific) Performance and Energy Bias Hint (EPB)
handling and expose it to user space via sysfs, fix and clean up
several cpufreq drivers, add support for two new chips to the qoriq
cpufreq driver, fix, simplify and clean up the cpufreq core and the
schedutil governor, add support for "CPU" domains to the generic power
domains (genpd) framework and provide low-level PSCI firmware support
for that feature, fix the exynos cpuidle driver and fix a couple of
issues in the devfreq subsystem and clean it up.
Specifics:
- Fix the handling of Performance and Energy Bias Hint (EPB) on Intel
processors and expose it to user space via sysfs to avoid having to
access it through the generic MSR I/F (Rafael Wysocki).
- Improve the handling of global turbo changes made by the platform
firmware in the intel_pstate driver (Rafael Wysocki).
- Convert some slow-path static_cpu_has() callers to boot_cpu_has()
in cpufreq (Borislav Petkov).
- Fix the frequency calculation loop in the armada-37xx cpufreq
driver (Gregory CLEMENT).
- Fix possible object reference leaks in multuple cpufreq drivers
(Wen Yang).
- Fix kerneldoc comment in the centrino cpufreq driver (dongjian).
- Clean up the ACPI and maple cpufreq drivers (Viresh Kumar, Mohan
Kumar).
- Add support for lx2160a and ls1028a to the qoriq cpufreq driver
(Vabhav Sharma, Yuantian Tang).
- Fix kobject memory leak in the cpufreq core (Viresh Kumar).
- Simplify the IOwait boosting in the schedutil cpufreq governor and
rework the TSC cpufreq notifier on x86 (Rafael Wysocki).
- Clean up the cpufreq core and statistics code (Yue Hu, Kyle Lin).
- Improve the cpufreq documentation, add SPDX license tags to some PM
documentation files and unify copyright notices in them (Rafael
Wysocki).
- Add support for "CPU" domains to the generic power domains (genpd)
framework and provide low-level PSCI firmware support for that
feature (Ulf Hansson).
- Rearrange the PSCI firmware support code and add support for
SYSTEM_RESET2 to it (Ulf Hansson, Sudeep Holla).
- Improve genpd support for devices in multiple power domains (Ulf
Hansson).
- Unify target residency for the AFTR and coupled AFTR states in the
exynos cpuidle driver (Marek Szyprowski).
- Introduce new helper routine in the operating performance points
(OPP) framework (Andrew-sh.Cheng).
- Add support for passing on-die termination (ODT) and auto power
down parameters from the kernel to Trusted Firmware-A (TF-A) to the
rk3399_dmc devfreq driver (Enric Balletbo i Serra).
- Add tracing to devfreq (Lukasz Luba).
- Make the exynos-bus devfreq driver suspend all devices on system
shutdown (Marek Szyprowski).
- Fix a few minor issues in the devfreq subsystem and clean it up
somewhat (Enric Balletbo i Serra, MyungJoo Ham, Rob Herring,
Saravana Kannan, Yangtao Li).
- Improve system wakeup diagnostics (Stephen Boyd).
- Rework filesystem sync messages emitted during system suspend and
hibernation (Harry Pan)"
* tag 'pm-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (72 commits)
cpufreq: Fix kobject memleak
cpufreq: armada-37xx: fix frequency calculation for opp
cpufreq: centrino: Fix centrino_setpolicy() kerneldoc comment
cpufreq: qoriq: add support for lx2160a
x86: tsc: Rework time_cpufreq_notifier()
PM / Domains: Allow to attach a CPU via genpd_dev_pm_attach_by_id|name()
PM / Domains: Search for the CPU device outside the genpd lock
PM / Domains: Drop unused in-parameter to some genpd functions
PM / Domains: Use the base device for driver_deferred_probe_check_state()
cpufreq: qoriq: Add ls1028a chip support
PM / Domains: Enable genpd_dev_pm_attach_by_id|name() for single PM domain
PM / Domains: Allow OF lookup for multi PM domain case from ->attach_dev()
PM / Domains: Don't kfree() the virtual device in the error path
cpufreq: Move ->get callback check outside of __cpufreq_get()
PM / Domains: remove unnecessary unlikely()
cpufreq: Remove needless bios_limit check in show_bios_limit()
drivers/cpufreq/acpi-cpufreq.c: This fixes the following checkpatch warning
firmware/psci: add support for SYSTEM_RESET2
PM / devfreq: add tracing for scheduling work
trace: events: add devfreq trace event file
...
Diffstat (limited to 'Documentation/admin-guide/pm/cpufreq.rst')
-rw-r--r-- | Documentation/admin-guide/pm/cpufreq.rst | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/Documentation/admin-guide/pm/cpufreq.rst b/Documentation/admin-guide/pm/cpufreq.rst index 7eca9026a9ed..0c74a7784964 100644 --- a/Documentation/admin-guide/pm/cpufreq.rst +++ b/Documentation/admin-guide/pm/cpufreq.rst @@ -1,3 +1,6 @@ +.. SPDX-License-Identifier: GPL-2.0 +.. include:: <isonum.txt> + .. |struct cpufreq_policy| replace:: :c:type:`struct cpufreq_policy <cpufreq_policy>` .. |intel_pstate| replace:: :doc:`intel_pstate <intel_pstate>` @@ -5,9 +8,10 @@ CPU Performance Scaling ======================= -:: +:Copyright: |copy| 2017 Intel Corporation + +:Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com> - Copyright (c) 2017 Intel Corp., Rafael J. Wysocki <rafael.j.wysocki@intel.com> The Concept of CPU Performance Scaling ====================================== @@ -396,8 +400,8 @@ RT or deadline scheduling classes, the governor will increase the frequency to the allowed maximum (that is, the ``scaling_max_freq`` policy limit). In turn, if it is invoked by the CFS scheduling class, the governor will use the Per-Entity Load Tracking (PELT) metric for the root control group of the -given CPU as the CPU utilization estimate (see the `Per-entity load tracking`_ -LWN.net article for a description of the PELT mechanism). Then, the new +given CPU as the CPU utilization estimate (see the *Per-entity load tracking* +LWN.net article [1]_ for a description of the PELT mechanism). Then, the new CPU frequency to apply is computed in accordance with the formula f = 1.25 * ``f_0`` * ``util`` / ``max`` @@ -698,4 +702,8 @@ hardware feature (e.g. all Intel ones), even if the :c:macro:`CONFIG_X86_ACPI_CPUFREQ_CPB` configuration option is set. -.. _Per-entity load tracking: https://lwn.net/Articles/531853/ +References +========== + +.. [1] Jonathan Corbet, *Per-entity load tracking*, + https://lwn.net/Articles/531853/ |