diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-22 00:26:28 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-22 00:26:28 +0300 |
commit | 02b82b02c34321dde10d003aafcd831a769b2a8a (patch) | |
tree | ead9a121b6fb2d37bbcc054f711b09d5bd788518 /Documentation/admin-guide | |
parent | 242ba6656d604aa8dc87451fc08143cb28d5a587 (diff) | |
parent | ec3d8b8365e9865b43099e943ec5f0bc12f28f96 (diff) | |
download | linux-02b82b02c34321dde10d003aafcd831a769b2a8a.tar.xz |
Merge tag 'pm-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki:
"These are mostly fixes and cleanups all over the code and a new piece
of documentation for Intel uncore frequency scaling.
Functionality-wise, the intel_idle driver will support Sapphire Rapids
Xeons natively now (with some extra facilities for controlling
C-states more precisely on those systems), virtual guests will take
the ACPI S4 hardware signature into account by default, the
intel_pstate driver will take the defualt EPP value from the firmware,
cpupower utility will support the AMD P-state driver added in the
previous cycle, and there is a new tracer utility for that driver.
Specifics:
- Allow device_pm_check_callbacks() to be called from interrupt
context without issues (Dmitry Baryshkov).
- Modify devm_pm_runtime_enable() to automatically handle
pm_runtime_dont_use_autosuspend() at driver exit time (Douglas
Anderson).
- Make the schedutil cpufreq governor use to_gov_attr_set() instead
of open coding it (Kevin Hao).
- Replace acpi_bus_get_device() with acpi_fetch_acpi_dev() in the
cpufreq longhaul driver (Rafael Wysocki).
- Unify show() and store() naming in cpufreq and make it use
__ATTR_XX (Lianjie Zhang).
- Make the intel_pstate driver use the EPP value set by the firmware
by default (Srinivas Pandruvada).
- Re-order the init checks in the powernow-k8 cpufreq driver (Mario
Limonciello).
- Make the ACPI processor idle driver check for architectural support
for LPI to avoid using it on x86 by mistake (Mario Limonciello).
- Add Sapphire Rapids Xeon support to the intel_idle driver (Artem
Bityutskiy).
- Add 'preferred_cstates' module argument to the intel_idle driver to
work around C1 and C1E handling issue on Sapphire Rapids (Artem
Bityutskiy).
- Add core C6 optimization on Sapphire Rapids to the intel_idle
driver (Artem Bityutskiy).
- Optimize the haltpoll cpuidle driver a bit (Li RongQing).
- Remove leftover text from intel_idle() kerneldoc comment and fix up
white space in intel_idle (Rafael Wysocki).
- Fix load_image_and_restore() error path (Ye Bin).
- Fix typos in comments in the system wakeup hadling code (Tom Rix).
- Clean up non-kernel-doc comments in hibernation code (Jiapeng
Chong).
- Fix __setup handler error handling in system-wide suspend and
hibernation core code (Randy Dunlap).
- Add device name to suspend_report_result() (Youngjin Jang).
- Make virtual guests honour ACPI S4 hardware signature by default
(David Woodhouse).
- Block power off of a parent PM domain unless child is in deepest
state (Ulf Hansson).
- Use dev_err_probe() to simplify error handling for generic PM
domains (Ahmad Fatoum).
- Fix sleep-in-atomic bug caused by genpd_debug_remove() (Shawn Guo).
- Document Intel uncore frequency scaling (Srinivas Pandruvada).
- Add DTPM hierarchy description (Daniel Lezcano).
- Change the locking scheme in DTPM (Daniel Lezcano).
- Fix dtpm_cpu cleanup at exit time and missing virtual DTPM pointer
release (Daniel Lezcano).
- Make dtpm_node_callback[] static (kernel test robot).
- Fix spelling mistake "initialze" -> "initialize" in
dtpm_create_hierarchy() (Colin Ian King).
- Add tracer tool for the amd-pstate driver (Jinzhou Su).
- Fix PC6 displaying in turbostat on some systems (Artem Bityutskiy).
- Add AMD P-State support to the cpupower utility (Huang Rui)"
* tag 'pm-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (58 commits)
cpufreq: powernow-k8: Re-order the init checks
cpuidle: intel_idle: Drop redundant backslash at line end
cpuidle: intel_idle: Update intel_idle() kerneldoc comment
PM: hibernate: Honour ACPI hardware signature by default for virtual guests
cpufreq: intel_pstate: Use firmware default EPP
cpufreq: unify show() and store() naming and use __ATTR_XX
PM: core: keep irq flags in device_pm_check_callbacks()
cpuidle: haltpoll: Call cpuidle_poll_state_init() later
Documentation: amd-pstate: add tracer tool introduction
tools/power/x86/amd_pstate_tracer: Add tracer tool for AMD P-state
tools/power/x86/intel_pstate_tracer: make tracer as a module
cpufreq: amd-pstate: Add more tracepoint for AMD P-State module
PM: sleep: Add device name to suspend_report_result()
turbostat: fix PC6 displaying on some systems
intel_idle: add core C6 optimization for SPR
intel_idle: add 'preferred_cstates' module argument
intel_idle: add SPR support
PM: runtime: Have devm_pm_runtime_enable() handle pm_runtime_dont_use_autosuspend()
ACPI: processor idle: Check for architectural support for LPI
cpuidle: PSCI: Move the `has_lpi` check to the beginning of the function
...
Diffstat (limited to 'Documentation/admin-guide')
-rw-r--r-- | Documentation/admin-guide/pm/amd-pstate.rst | 26 | ||||
-rw-r--r-- | Documentation/admin-guide/pm/intel_uncore_frequency_scaling.rst | 60 | ||||
-rw-r--r-- | Documentation/admin-guide/pm/working-state.rst | 1 |
3 files changed, 87 insertions, 0 deletions
diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst index 2f066df4ee9c..1923cb25073b 100644 --- a/Documentation/admin-guide/pm/amd-pstate.rst +++ b/Documentation/admin-guide/pm/amd-pstate.rst @@ -369,6 +369,32 @@ governor (for the policies it is attached to), or by the ``CPUFreq`` core (for t policies with other scaling governors). +Tracer Tool +------------- + +``amd_pstate_tracer.py`` can record and parse ``amd-pstate`` trace log, then +generate performance plots. This utility can be used to debug and tune the +performance of ``amd-pstate`` driver. The tracer tool needs to import intel +pstate tracer. + +Tracer tool located in ``linux/tools/power/x86/amd_pstate_tracer``. It can be +used in two ways. If trace file is available, then directly parse the file +with command :: + + ./amd_pstate_trace.py [-c cpus] -t <trace_file> -n <test_name> + +Or generate trace file with root privilege, then parse and plot with command :: + + sudo ./amd_pstate_trace.py [-c cpus] -n <test_name> -i <interval> [-m kbytes] + +The test result can be found in ``results/test_name``. Following is the example +about part of the output. :: + + common_cpu common_secs common_usecs min_perf des_perf max_perf freq mperf apef tsc load duration_ms sample_num elapsed_time common_comm + CPU_005 712 116384 39 49 166 0.7565 9645075 2214891 38431470 25.1 11.646 469 2.496 kworker/5:0-40 + CPU_006 712 116408 39 49 166 0.6769 8950227 1839034 37192089 24.06 11.272 470 2.496 kworker/6:0-1264 + + Reference =========== diff --git a/Documentation/admin-guide/pm/intel_uncore_frequency_scaling.rst b/Documentation/admin-guide/pm/intel_uncore_frequency_scaling.rst new file mode 100644 index 000000000000..09169d935835 --- /dev/null +++ b/Documentation/admin-guide/pm/intel_uncore_frequency_scaling.rst @@ -0,0 +1,60 @@ +.. SPDX-License-Identifier: GPL-2.0 +.. include:: <isonum.txt> + +============================== +Intel Uncore Frequency Scaling +============================== + +:Copyright: |copy| 2022 Intel Corporation + +:Author: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> + +Introduction +------------ + +The uncore can consume significant amount of power in Intel's Xeon servers based +on the workload characteristics. To optimize the total power and improve overall +performance, SoCs have internal algorithms for scaling uncore frequency. These +algorithms monitor workload usage of uncore and set a desirable frequency. + +It is possible that users have different expectations of uncore performance and +want to have control over it. The objective is similar to allowing users to set +the scaling min/max frequencies via cpufreq sysfs to improve CPU performance. +Users may have some latency sensitive workloads where they do not want any +change to uncore frequency. Also, users may have workloads which require +different core and uncore performance at distinct phases and they may want to +use both cpufreq and the uncore scaling interface to distribute power and +improve overall performance. + +Sysfs Interface +--------------- + +To control uncore frequency, a sysfs interface is provided in the directory: +`/sys/devices/system/cpu/intel_uncore_frequency/`. + +There is one directory for each package and die combination as the scope of +uncore scaling control is per die in multiple die/package SoCs or per +package for single die per package SoCs. The name represents the +scope of control. For example: 'package_00_die_00' is for package id 0 and +die 0. + +Each package_*_die_* contains the following attributes: + +``initial_max_freq_khz`` + Out of reset, this attribute represent the maximum possible frequency. + This is a read-only attribute. If users adjust max_freq_khz, + they can always go back to maximum using the value from this attribute. + +``initial_min_freq_khz`` + Out of reset, this attribute represent the minimum possible frequency. + This is a read-only attribute. If users adjust min_freq_khz, + they can always go back to minimum using the value from this attribute. + +``max_freq_khz`` + This attribute is used to set the maximum uncore frequency. + +``min_freq_khz`` + This attribute is used to set the minimum uncore frequency. + +``current_freq_khz`` + This attribute is used to get the current uncore frequency. diff --git a/Documentation/admin-guide/pm/working-state.rst b/Documentation/admin-guide/pm/working-state.rst index 5d2757e2de65..ee45887811ff 100644 --- a/Documentation/admin-guide/pm/working-state.rst +++ b/Documentation/admin-guide/pm/working-state.rst @@ -15,3 +15,4 @@ Working-State Power Management cpufreq_drivers intel_epb intel-speed-select + intel_uncore_frequency_scaling |