Re: [PATCH v10 00/12] Implement AMD Pstate EPP Driver

Huang Rui
2023-01-17T14:04:35Z

On Fri, Jan 06, 2023 at 02:14:08PM +0800, Yuan, Perry wrote:
> Hi all,
>
> This patchset implements one new AMD CPU frequency driver
> `amd-pstate-epp` instance for better performance and power control.
> CPPC has a parameter called energy preference performance (EPP).
> The EPP is used in the CCLK DPM controller to drive the frequency that a core
> is going to operate during short periods of activity.
> EPP values will be utilized for different OS profiles (balanced, performance, power savings).
>
> AMD Energy Performance Preference (EPP) provides a hint to the hardware
> if software wants to bias toward performance (0x0) or energy efficiency (0xff)
> The lowlevel power firmware will calculate the runtime frequency according to the EPP preference
> value. So the EPP hint will impact the CPU cores frequency responsiveness.
>
> We use the RAPL interface with "perf" tool to get the energy data of the package power.
> Performance Per Watt (PPW) Calculation:
>
> The PPW calculation is referred by below paper:
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsoftware.intel.com%2Fcontent%2Fdam%2Fdevelop%2Fexternal%2Fus%2Fen%2Fdocuments%2Fperformance-per-what-paper.pdf&amp;data=04%7C01%7CPerry.Yuan%40amd.com%7Cac66e8ce98044e9b062708d9ab47c8d8%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637729147708574423%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&amp;sdata=TPOvCE%2Frbb0ptBreWNxHqOi9YnVhcHGKG88vviDLb00%3D&amp;reserved=0
>
> Below formula is referred from below spec to measure the PPW:
>
> (F / t) / P = F * t / (t * E) = F / E,
>
> "F" is the number of frames per second.
> "P" is power measured in watts.
> "E" is energy measured in joules.
>
> Gitsouce Benchmark Data on ROME Server CPU
> +------------------------------+------------------------------+------------+------------------+
> | Kernel Module | PPW (1 / s * J) |Energy(J) | PPW Improvement (%)|
> +==============================+==============================+============+==================+
> | acpi-cpufreq:schedutil | 5.85658E-05 | 17074.8 | base |
> +------------------------------+------------------------------+------------+------------------+
> | acpi-cpufreq:ondemand | 5.03079E-05 | 19877.6 | -14.10% |
> +------------------------------+------------------------------+------------+------------------+
> | acpi-cpufreq:performance | 5.88132E-05 | 17003 | 0.42% |
> +------------------------------+------------------------------+------------+------------------+
> | amd-pstate:ondemand | 4.60295E-05 | 21725.2 | -21.41% |
> +------------------------------+------------------------------+------------+------------------+
> | amd-pstate:schedutil | 4.70026E-05 | 21275.4 | -19.7% |
> +------------------------------+------------------------------+------------+------------------+
> | amd-pstate:performance | 5.80094E-05 | 17238.6 | -0.95% |
> +------------------------------+------------------------------+------------+------------------+
> | EPP:performance | 5.8292E-05 | 17155 | -0.47% |
> +------------------------------+------------------------------+------------+------------------+
> | EPP: balance performance: | 6.71709E-05 | 14887.4 | 14.69% |
> +------------------------------+------------------------------+------------+------------------+
> | EPP:power | 6.66951E-05 | 4993.6 | 13.88% |
> +------------------------------+------------------------------+------------+------------------+
>
> Tbench Benchmark Data on ROME Server CPU
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | Kernel Module | PPW MB / (s * J) |Throughput(MB/s)| Energy (J)|PPW Improvement(%)|
> +=============================================+===================+==============+=============+==================+
> | acpi_cpufreq: schedutil | 46.39 | 17191 | 37057.3 | base |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | acpi_cpufreq: ondemand | 51.51 | 19269.5 | 37406.5 | 11.04 % |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | acpi_cpufreq: performance | 45.96 | 17063.7 | 37123.7 | -0.74 % |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | EPP:powersave: performance(0) | 54.46 | 20263.1 | 37205 | 17.87 % |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | EPP:powersave: balance performance | 55.03 | 20481.9 | 37221.5 | 19.14 % |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | EPP:powersave: balance_power | 54.43 | 20245.9 | 37194.2 | 17.77 % |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | EPP:powersave: power(255) | 54.26 | 20181.7 | 37197.4 | 17.40 % |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | amd-pstate: schedutil | 48.22 | 17844.9 | 37006.6 | 3.80 % |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | amd-pstate: ondemand | 61.30 | 22988 | 37503.4 | 33.72 % |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | amd-pstate: performance | 54.52 | 20252.6 | 37147.8 | 17.81 % |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
>
> changes from v9:
> * pick up R-B flas added by Mario
> * pick up R-B flag added by Wyes
> * rename "default_pstate_driver" to "current_pstate_driver"
> * update status string to "disable" when driver disabled and update size check
> * move the common macro definition of EPP to cppc library files for intel_pstate and amd_pstate common using
> * fix some doc words for new global sysfs patch
>
> changes from v8:
> * drive all the feedbacks from Mario and change the codes in this
> version
> * drive all the feedbacks from Ray and change the codes in this
> version
> * pick up all the R-B flags from Mario
> * pick up all the R-B flags from Ray
> * drop boost/refresh_freq_limits callback
> * reuse policy->driver_data to store amd_cpudata struct
> * use switch-case in the driver mode switching function
> * add Kconfig dependency the INTEL_PSTATE for AMD_PSTATE build
> * fix some other code format and typos
>
> changes from v7:
> * remove iowait boost functions code
> * pick up ack by flag from Huang Ray.
> * add one new patch to support multiple working modes in the amd_pstate_param(),aligned with Wyse
> * drop the patch "[v7 08/13] cpufreq: amd-pstate: add frequency dynamic boost sysfs control"
> * replace the cppc_get_epp_caps() with new cppc_get_epp_perf() wihch is
> more simple to use
> * remove I/O wait boost code from amd_pstate_update_status()
> * replace cppc_active var with enum type AMD_PSTATE_ACTIVE
> * squash amd_pstate_epp_verify_policy() into sigle function
> * remove "amd pstate" string from the pr_err, pr_debug logs info
> * rework patch [v7 03/13], move the common EPP profiles declaration
> into cpufreq.h which will be used by amd-pstate and intel-pstate
> * combine amd psate init functions.
> * remove epp_powersave from amd-pstate.h and dropping the codes.
> * move amd_pstate_params{} from amd-pstate.h into amd-pstate.c
> * drive some other feedbacks from huang ray
>
> changes from v6:
> * fix one legacy kernel hang issue when amd-pstate driver unregistering
> * add new documentation to introduce new global sysfs attributes
> * use sysfs_emit_at() to print epp profiles array
> * update commit info for patch v6 patch 1/11 as Mario sugguested.
> * trying to add the EPP profiles into cpufreq.h, but it will cause lots
> of build failues,continue to keep cpufreq_common.h used in v7
> * update commit info using amd-pstate as prefix same as before.
> * remove CONFIG_ACPI for the header as Ray suggested.
> * move amd_pstate_kobj to where it is used in patch "add frequency dynamic boost sysfs control"
> * drive feedback removing X86_FEATURE_CPPC check for the epp init from Huang Ray
> * drive feedback from Mario
>
> change from v5:
> * add one common header `cpufreq_commoncpufreq_common` to extract EPP profiles
> definition for amd and intel pstate driver.
> * remove the epp_off value to avoid confusion.
> * convert some other sysfs sprintf() function with sysfs_emit() and add onew new patch
> * add acpi pm server priofile detection to enable dynamic boost control
> * fix some code format with checkpatch script
> * move the EPP profile declaration into common header file `cpufreq_common.h`
> * fix commit typos
>
> changes from v4:
> * rebase driver based on the v6.1-rc7
> * remove the builtin changes patch because pstate driver has been
> changed to builtin type by another thread patch
> * update Documentation: amd-pstate: add amd pstate driver mode introduction
> * replace sprintf with sysfs_emit() instead.
> * fix typo for cppc_set_epp_perf() in cppc_acpi.h header
>
> changes from v3:
> * add one more document update patch for the active and passive mode
> introducion.
> * drive most of the feedbacks from Mario
> * drive feedback from Rafael for the cppc_acpi driver.
> * remove the epp raw data set/get function
> * set the amd-pstate drive by passing kernel parameter
> * set amd-pstate driver disabled by default if no kernel parameter
> input from booting
> * get cppc_set_auto_epp and cppc_set_epp_perf combined
> * pick up reviewed by flag from Mario
>
> changes from v2:
> * change pstate driver as builtin type from module
> * drop patch "export cpufreq cpu release and acquire"
> * squash patch of shared mem into single patch of epp implementation
> * add one new patch to support frequency boost control
> * add patch to expose driver working status checking
> * rebase driver into v6.1-rc4 kernel release
> * move some declaration to amd-pstate.h
> * drive feedback from Mario for the online/offline patch
> * drive feedback from Mario for the suspend/resume patch
> * drive feedback from Ray for the cppc_acpi and some other patches
> * drive feedback from Nathan for the epp patch
>
> changes from v1:
> * rebased to v6.0
> * drive feedbacks from Mario for the suspend/resume patch
> * drive feedbacks from Nathan for the EPP support on msr type
> * fix some typos and code style indent problems
> * update commit comments for patch 4/7
> * change the `epp_enabled` module param name to `epp`
> * set the default epp mode to be false
> * add testing for the x86_energy_perf_policy utility patchset(will
> send that utility patchset with another thread)

Most of the patches look good for me, thanks!

Only patch 3, as Intel P-State actually won't use CPPC (won't expose _CPC
object in SBIOS), it may not be good to align the common definition in
acpi_cppc.h.

Thanks,
Ray

>
> v9: https://lore.kernel.org/lkml/20221225163442.2205660-1-perry.yuan@amd.com/
> v8: https://lore.kernel.org/lkml/20221219064042.661122-1-perry.yuan@amd.com/
> v7: https://lore.kernel.org/lkml/20221208111852.386731-1-perry.yuan@amd.com/
> v6: https://lore.kernel.org/lkml/20221202074719.623673-1-perry.yuan@amd.com/
> v5: https://lore.kernel.org/lkml/20221128170314.2276636-1-perry.yuan@amd.com/
> v4: https://lore.kernel.org/lkml/20221110175847.3098728-1-Perry.Yuan@amd.com/
> v3: https://lore.kernel.org/all/20221107175705.2207842-1-Perry.Yuan@amd.com/
> v2: https://lore.kernel.org/all/20221010162248.348141-1-Perry.Yuan@amd.com/
> v1: https://lore.kernel.org/all/20221009071033.21170-1-Perry.Yuan@amd.com/
>
> Perry Yuan (11):
> ACPI: CPPC: Add AMD pstate energy performance preference cppc control
> Documentation: amd-pstate: add EPP profiles introduction
> cpufreq: intel_pstate: use common macro definition for Energy
> Preference Performance(EPP)
> cpufreq: amd-pstate: implement Pstate EPP support for the AMD
> processors
> cpufreq: amd-pstate: implement amd pstate cpu online and offline
> callback
> cpufreq: amd-pstate: implement suspend and resume callbacks
> cpufreq: amd-pstate: add driver working mode switch support
> Documentation: amd-pstate: add amd pstate driver mode introduction
> Documentation: introduce amd pstate active mode kernel command line
> options
> cpufreq: amd-pstate: convert sprintf with sysfs_emit()
> Documentation: amd-pstate: introduce new global sysfs attributes
>
> Wyes Karny (1):
> cpufreq: amd-pstate: optimize driver working mode selection in
> amd_pstate_param()
>
> .../admin-guide/kernel-parameters.txt | 7 +
> Documentation/admin-guide/pm/amd-pstate.rst | 74 +-
> drivers/acpi/cppc_acpi.c | 96 +++
> drivers/cpufreq/amd-pstate.c | 659 +++++++++++++++++-
> drivers/cpufreq/intel_pstate.c | 36 -
> include/acpi/cppc_acpi.h | 22 +
> include/linux/amd-pstate.h | 28 +
> 7 files changed, 865 insertions(+), 57 deletions(-)
>
> --
> 2.34.1
>