There are some performance issues being identified by dynamic EPP
and we don't want to have distributions turning it on by default
exposing them to users at this time.
Drop the kconfig option, and require an explicit opt in from kernel
command line or runtime sysfs option to turn it on.
Reported-by: Viktor Jägersküpper <viktor_jaegerskuepper@freenet.de>
Closes: https://lore.kernel.org/linux-pm/14a87c99-785c-4b16-bfce-35ecbf053448@freenet.de/
Reported-by: Stuart Meckle <stuartmeckle@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221473
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20260512221947.1652988-1-mario.limonciello@amd.com
(fix sysfs file path)
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
The energy performance preference field of the CPPC request MSR
supports values from 0 to 255, but the strings only offer 4 values.
The other values are useful for tuning the performance of some
workloads.
Add support for writing the raw energy performance preference value
to the sysfs file. If the last value written was an integer then
an integer will be returned. If the last value written was a string
then a string will be returned.
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
The platform profile core allows multiple drivers and devices to
register platform profile support.
When the legacy platform profile interface is used all drivers will
adjust the platform profile as well.
Add support for registering every CPU with the platform profile handler
when dynamic EPP is enabled.
The end result will be that changing the platform profile will modify
EPP accordingly.
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Add `amd_dynamic_epp=enable` and `amd_dynamic_epp=disable` to override
the kernel configuration option `CONFIG_X86_AMD_PSTATE_DYNAMIC_EPP`
locally.
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Dynamic energy performance preference changes the EPP profile based on
whether the machine is running on AC or DC power.
A notification chain from the power supply core is used to adjust EPP
values on plug in or plug out events.
When enabled, the driver exposes a sysfs toggle for dynamic EPP, blocks
manual writes to energy_performance_preference while it "owns" the EPP
updates.
For non-server systems:
* the default EPP for AC mode is `performance`.
* the default EPP for DC mode is `balance_performance`.
For server systems dynamic EPP is mostly a no-op.
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
The links for AMD64 Architecture Programmer's Manual and PPR for AMD
Family 19h Model 51h, Revision A1 Processors redirect to a generic page.
Update the links to the working ones.
Signed-off-by: Ninad Naik <ninadnaik07@gmail.com>
Link: https://lore.kernel.org/r/20260330190855.1115304-1-ninadnaik07@gmail.com
Acked-by: Mario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Add documentation for the sysfs files
/sys/devices/system/cpu/cpufreq/policy*/amd_pstate_floor_freq
and
/sys/devices/system/cpu/cpufreq/policy*/amd_pstate_floor_count.
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Add the missing amd_pstate_prefcore_ranking filenames in the sysfs
listing example leading to the descriptions of these
parameters. Clarify when will the file be visible.
Fixes: 15a2b764ea ("amd-pstate: Add missing documentation for `amd_pstate_prefcore_ranking`")
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Add the missing amd_pstate_hw_prefcore filenames in the sysfs listing
example leading to the descriptions of these parameters. Clarify when
will the file be visible.
Fixes: b96b82d1af ("cpufreq: amd-pstate: Add documentation for `amd_pstate_hw_prefcore`")
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
In the AMD P-States Performance Scale diagram, the labels for "Max Perf"
and "Lowest Perf" were incorrectly used to define the range for
"Desired Perf".The "Desired performance target" should be bounded by the
"Maximum requested performance" and the "Minimum requested performance",
which corresponds to "Max Perf" and "Min Perf", respectively.
Signed-off-by: Shouye Liu <shouyeliu@tencent.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20250522070140.17557-1-shouyeliu@gmail.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
commit ad4caad58d ("cpufreq: amd-pstate: Merge
amd_pstate_highest_perf_set() into amd_get_boost_ratio_numerator()")
changed the semantics for highest perf and commit 18d9b52271
("cpufreq/amd-pstate: Use nominal perf for limits when boost is disabled")
worked around those semantic changes.
This however is a confusing result and furthermore makes it awkward to
change frequency limits and boost due to the scaling differences. Restore
the boost numerator to highest perf again.
Suggested-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Fixes: ad4caad58d ("cpufreq: amd-pstate: Merge amd_pstate_highest_perf_set() into amd_get_boost_ratio_numerator()")
Link: https://lore.kernel.org/r/20241209185248.16301-2-mario.limonciello@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
`amd_pstate_prefcore_ranking` reflects the dynamic rankings of a CPU
core based on platform conditions. Explicitly include it in the
documentation.
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Explain that the sysfs file represents both preferred core being
enabled by the user and supported by the hardware.
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
The special case in amd_pstate_highest_perf_set() is the value used
for calculating the boost numerator. Merge this into
amd_get_boost_ratio_numerator() and then use that to calculate boost
ratio.
This allows dropping more special casing of the highest perf value.
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Updates the documentation in `amd-pstate.rst` to include information about
the per CPU boost control feature. Users can now enable or disable the
Core Performance Boost (CPB) feature on individual CPUs using the `boost`
sysfs attribute.
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Perry Yuan <perry.yuan@amd.com>
Co-developed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20240626042733.3747-5-mario.limonciello@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
the guided mode is also supported, so the operation mode should include
that mode as well.
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Perry Yuan <perry.yuan@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Link: https://lore.kernel.org/r/a61d825ef71f6aacc8f1624fe9fb982b8446b5a7.1718811234.git.perry.yuan@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Title under line too short
Signed-off-by: Meng Li <li.meng@amd.com>
[ rjw: Subject edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Introduce amd-pstate preferred core.
check preferred core state set by the kernel parameter:
$ cat /sys/devices/system/cpu/amd-pstate/prefcore
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Reviewed-by: Wyes Karny <wyes.karny@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Perry Yuan <perry.yuan@amd.com>
Signed-off-by: Meng Li <li.meng@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Fix two typos in the admin-guide:
- a missing e in "reference_perf" in cppc_sysfs.rst.
- the amd_pstate sysfs path uses a dash instead of an underscore.
Signed-off-by: Erwan Velu <e.velu@criteo.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
changes include:
- Some significant additions to the memory-management documentation
- Some improvements to navigation in the HTML-rendered docs
- More Spanish and Chinese translations
...and the usual set of typo fixes and such.
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Merge tag 'docs-6.3' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"It has been a moderately calm cycle for documentation; the significant
changes include:
- Some significant additions to the memory-management documentation
- Some improvements to navigation in the HTML-rendered docs
- More Spanish and Chinese translations
... and the usual set of typo fixes and such"
* tag 'docs-6.3' of git://git.lwn.net/linux: (68 commits)
Documentation/watchdog/hpwdt: Fix Format
Documentation/watchdog/hpwdt: Fix Reference
Documentation: core-api: padata: correct spelling
docs/mm: Physical Memory: correct spelling in reference to CONFIG_PAGE_EXTENSION
docs: Use HTML comments for the kernel-toc SPDX line
docs: Add more information to the HTML sidebar
Documentation: KVM: Update AMD memory encryption link
printk: Document that CONFIG_BOOT_PRINTK_DELAY required for boot_delay=
Documentation: userspace-api: correct spelling
Documentation: sparc: correct spelling
Documentation: driver-api: correct spelling
Documentation: admin-guide: correct spelling
docs: add workload-tracing document to admin-guide
docs/admin-guide/mm: remove useless markup
docs/mm: remove useless markup
docs/mm: Physical Memory: remove useless markup
docs/sp_SP: Add process magic-number translation
docs: ftrace: always use canonical ftrace path
Doc/damon: fix the data path error
dma-buf: Add "dma-buf" to title of documentation
...
kernel test robot reported htmldocs warning:
Documentation/admin-guide/pm/amd-pstate.rst:343: WARNING: duplicate label admin-guide/pm/amd-pstate:user space interface in ``sysfs``, other instance in Documentation/admin-guide/pm/amd-pstate.rst
The documentation contains two sections with the same "User Space Interface
in ``sysfs``" title. The first one deals with per-policy sysfs and the
second one is about general attributes (currently only global attributes
are documented).
Disambiguate title text of both sections to fix the warning.
Link: https://lore.kernel.org/linux-doc/202302151041.0SWs1RHK-lkp@intel.com/
Fixes: b9e6a2d47b ("Documentation: amd-pstate: introduce new global sysfs attributes")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reviewed-by: Wyes Karny <wyes.karny@amd.com>
Acked-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The amd-pstate driver supports switching working modes at runtime.
Users can view and change modes by interacting with the "status" sysfs
attribute.
1) check driver mode:
$ cat /sys/devices/system/cpu/amd-pstate/status
2) switch mode:
`# echo "passive" | sudo tee /sys/devices/system/cpu/amd-pstate/status`
or
`# echo "active" | sudo tee /sys/devices/system/cpu/amd-pstate/status`
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Wyes Karny <wyes.karny@amd.com>
Tested-by: Wyes Karny <wyes.karny@amd.com>
Signed-off-by: Perry Yuan <perry.yuan@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The amd-pstate driver has two operation modes supported:
* CPPC Autonomous (active) mode
* CPPC non-autonomous (passive) mode.
active mode and passive mode can be chosen by different kernel parameters.
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Wyes Karny <wyes.karny@amd.com>
Tested-by: Wyes Karny <wyes.karny@amd.com>
Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The amd-pstate driver supports a feature called energy performance
preference (EPP). Add information to the documentation to explain
how users can interact with the sysfs files for this feature.
1) See all EPP profiles
$ sudo cat /sys/devices/system/cpu/cpu0/cpufreq/energy_performance_available_preferences
default performance balance_performance balance_power power
2) Check current EPP profile
$ sudo cat /sys/devices/system/cpu/cpu0/cpufreq/energy_performance_preference
performance
3) Set new EPP profile
$ sudo bash -c "echo power > /sys/devices/system/cpu/cpu0/cpufreq/energy_performance_preference"
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Wyes Karny <wyes.karny@amd.com>
Tested-by: Wyes Karny <wyes.karny@amd.com>
Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This Kselftest update for Linux 6.2-rc1 consists of several fixes
and enhancements to existing tests and a few new tests:
- adds new amd-pstate and fixes and enhances existing ones
- adds new watchdog tests and enhances existing ones to improve coverage
- fixes to ftrace, splice_read, rtc, and efivars tests
- fixes to handle egrep obsolescence in the latest grep release
- miscellaneous spelling and SPDX fixes
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Merge tag 'linux-kselftest-next-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull Kselftest updates from Shuah Khan:
"Several fixes and enhancements to existing tests and a few new tests:
- add new amd-pstate tests and fix and enhance existing ones
- add new watchdog tests and enhance existing ones to improve
coverage
- fixes to ftrace, splice_read, rtc, and efivars tests
- fixes to handle egrep obsolescence in the latest grep release
- miscellaneous spelling and SPDX fixes"
* tag 'linux-kselftest-next-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (24 commits)
selftests/ftrace: Use long for synthetic event probe test
selftests/tpm2: Split async tests call to separate shell script runner
selftests: splice_read: Fix sysfs read cases
selftests: ftrace: Use "grep -E" instead of "egrep"
selftests: gpio: Use "grep -E" instead of "egrep"
selftests: kselftest_deps: Use "grep -E" instead of "egrep"
selftests/efivarfs: Add checking of the test return value
cpufreq: amd-pstate: fix spdxcheck warnings for amd-pstate-ut.c
selftests: rtc: skip when RTC is not present
selftests/ftrace: event_triggers: wait longer for test_event_enable
selftests/vDSO: Add riscv getcpu & gettimeofday test
Documentation: amd-pstate: Add tbench and gitsource test introduction
selftests: amd-pstate: Trigger gitsource benchmark and test cpus
selftests: amd-pstate: Trigger tbench benchmark and test cpus
selftests: amd-pstate: Split basic.sh into run.sh and basic.sh.
selftests: amd-pstate: Rename amd-pstate-ut.sh to basic.sh.
selftests/ftrace: Convert tracer tests to use 'requires' to specify program dependency
selftests/ftrace: Add check for ping command for trigger tests
selftests/watchdog: Fix spelling mistake "Temeprature" -> "Temperature"
selftests/watchdog: add test for WDIOC_GETTEMP
...
Introduce the `amd_pstate` driver new working mode with
`amd_pstate=passive` added to kernel command line.
If there is no passive mode enabled by user, amd_pstate driver will be
disabled by default for now.
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Tested-by: Wyes Karny <wyes.karny@amd.com>
Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Introduce tbench and gitsource test cases design and implementation.
Monitor cpus changes about performance and power consumption etc.
Signed-off-by: Meng Li <li.meng@amd.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Introduce the AMD P-State unit test module design and implementation.
It also talks about kselftest and how to use.
Signed-off-by: Meng Li <li.meng@amd.com>
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Merge additional power management documentation udates for 5.18-rc1:
- Add Intel uncore frequency scaling documentation file to its
MAINTAINERS entry (Srinivas Pandruvada).
- Clean up the AMD P-state driver documentation (Jan Engelhardt).
* pm-docs:
Documentation: amd-pstate: grammar and sentence structure updates
MAINTAINERS: Add additional file to uncore frequency control
Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Introduce the AMD P-State driver design and implementation.
Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
