mbox series

[v3,0/8] Implement AMD Pstate EPP Driver

Message ID 20221107175705.2207842-1-Perry.Yuan@amd.com
Headers
Series Implement AMD Pstate EPP Driver |

Message

Yuan, Perry Nov. 7, 2022, 5:56 p.m. UTC 
  From: Perry Yuan <perry.yuan@amd.com>

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 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)

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 (8):
  ACPI: CPPC: Add AMD pstate energy performance preference cppc control
  Documentation: amd-pstate: add EPP profiles introduction
  cpufreq: amd-pstate: change driver to be built-in type
  cpufreq: amd_pstate: add AMD Pstate EPP support for the MSR based
    processors
  cpufreq: amd_pstate: implement amd pstate cpu online and offline
    callback
  cpufreq: amd-pstate: implement suspend and resume callbacks
  cpufreq: amd-pstate: add frequency dynamic boost sysfs control
  cpufreq: amd_pstate: add driver working mode status sysfs entry

 Documentation/admin-guide/pm/amd-pstate.rst |  19 +
 drivers/acpi/cppc_acpi.c                    | 126 +++
 drivers/cpufreq/amd-pstate.c                | 905 +++++++++++++++++++-
 include/acpi/cppc_acpi.h                    |  17 +
 include/linux/amd-pstate.h                  |  82 ++
 5 files changed, 1135 insertions(+), 14 deletions(-)