[PATCH v9 0/7] AMD Pstate Driver Core Performance Boost

From: Perry Yuan
Date: Mon May 06 2024 - 06:22:30 EST


Hi all,
The patchset series add core performance boost feature for AMD pstate
driver including passisve ,guide and active mode support.

User can change core frequency boost control with a new sysfs entry:

"/sys/devices/system/cpu/amd_pstate/cpb_boost"


1) disable core boost:
$ sudo bash -c "echo 0 > /sys/devices/system/cpu/amd_pstate/cpb_boost"
$ lscpu -ae
CPU NODE SOCKET CORE L1d:L1i:L2:L3 ONLINE MAXMHZ MINMHZ MHZ
0 0 0 0 0:0:0:0 yes 4201.0000 400.0000 2983.578
1 0 0 1 1:1:1:0 yes 4201.0000 400.0000 2983.578
2 0 0 2 2:2:2:0 yes 4201.0000 400.0000 2583.855
3 0 0 3 3:3:3:0 yes 4201.0000 400.0000 2983.578
4 0 0 4 4:4:4:0 yes 4201.0000 400.0000 2983.578

2) enable core boost:
$ sudo bash -c "echo 1 > /sys/devices/system/cpu/amd_pstate/cpb_boost"
$ lscpu -ae
0 0 0 0 0:0:0:0 yes 5759.0000 400.0000 2983.578
1 0 0 1 1:1:1:0 yes 5759.0000 400.0000 2983.578
2 0 0 2 2:2:2:0 yes 5759.0000 400.0000 2983.578
3 0 0 3 3:3:3:0 yes 5759.0000 400.0000 2983.578
4 0 0 4 4:4:4:0 yes 5759.0000 400.0000 2983.578


============================================================================
The V9 patches add per CPU boost control, user can enable/disable CPUs boost
as the below command tested on a laptop system.
# before
CPU NODE SOCKET CORE L1d:L1i:L2:L3 ONLINE MAXMHZ MINMHZ MHZ
0 0 0 0 0:0:0:0 yes 4208.0000 400.0000 1666.7740
1 0 0 0 0:0:0:0 yes 4208.0000 400.0000 400.0000
2 0 0 1 1:1:1:0 yes 4208.0000 400.0000 3386.1260
3 0 0 1 1:1:1:0 yes 4208.0000 400.0000 400.0000
$ sudo rdmsr 0xc00102b3 -p 0
10a6

$ sudo bash -c "echo 1 > /sys/devices/system/cpu/cpu0/cpufreq/amd_pstate_boost_cpb"
# after
CPU NODE SOCKET CORE L1d:L1i:L2:L3 ONLINE MAXMHZ MINMHZ MHZ
0 0 0 0 0:0:0:0 yes 3501.0000 400.0000 400.0000
1 0 0 0 0:0:0:0 yes 4208.0000 400.0000 1391.0690
2 0 0 1 1:1:1:0 yes 4208.0000 400.0000 3654.4541
3 0 0 1 1:1:1:0 yes 4208.0000 400.0000 400.0000
$ sudo rdmsr 0xc00102b3 -p 0
108a


The patches have been tested with the AMD 7950X processor and many users
would like to get core boost control enabled for power saving.

Perry.

Changes from v8:
* pick RB flag for patch 4 (Mario)
* change boot_cpu_has to cpu_feature_enabled for patch 2 (Boris)
* merge patch 6 into patch 3 (Mario)
* add two patch for per CPU boost control patch 6 & 7(Mario)
* rebased to latest linux-pm/bleeding-edge

Changes from v7:
* fix the mutext locking issue in the sysfs file update(Ray, Mario)
* pick ack flag from Ray
* use X86_FEATURE_CPB to verify the CPB function in Patch #2(Ray)
* rerun the testing to check function works well
* rebased to linux-pm/bleeding-edge latest

Changes from v6:
* reword patch 2 commit log (Gautham)
* update cover letter description(Gautham)
* rebase to kernel v6.9-rc5

Changes from v4:
* drop the legacy boost remove patch, let us keep the legacy interface
in case some applications break.
* rebase to linux-pm/bleeding-edge branch
* rework the patchset base on [PATCH v8 0/8] AMD Pstate Fixes And
Enhancements which has some intial work done there.

Changes from v4:
* move MSR_K7_HWCR_CPB_DIS_BIT into msr-index.h
* pick RB flag from Gautham R. Shenoy
* add Cc Oleksandr Natalenko <oleksandr@xxxxxxxxxxxxxx>
* rebase to latest linux-pm/bleeding-edge branch
* rebase the patch set on top of [PATCH v7 0/6] AMD Pstate Fixes And Enhancements
* update [PATCH v7 2/6] to use MSR_K7_HWCR_CPB_DIS_BIT

Changes from v3:
* rebased to linux-pm/bleeding-edge v6.8
* rename global to amd_pstate_global_params(Oleksandr Natalenko)
* remove comments for boot_supported in amd_pstate.h
* fix the compiler warning for amd-pstate-ut.ko
* use for_each_online_cpu in cpb_boost_store which fix the null pointer
error during testing
* fix the max frequency value to be KHz when cpb boost disabled(Gautham R. Shenoy)

Changes from v2:
* move global struct to amd-pstate.h
* fix the amd-pstate-ut with new cpb control interface

Changes from v1:
* drop suspend/resume fix patch 6/7 because of the fix should be in
another fix series instead of CPB feature
* move the set_boost remove patch to the last(Mario)
* Fix commit info with "Closes:" (Mario)
* simplified global.cpb_supported initialization(Mario)
* Add guide mode support for CPB control
* Fixed some Doc typos and add guide mode info to Doc as well.

v1: https://lore.kernel.org/all/cover.1706255676.git.perry.yuan@xxxxxxx/
v2: https://lore.kernel.org/lkml/cover.1707047943.git.perry.yuan@xxxxxxx/
v3: https://lore.kernel.org/lkml/cover.1707297581.git.perry.yuan@xxxxxxx/
v4: https://lore.kernel.org/lkml/cover.1710322310.git.perry.yuan@xxxxxxx/
v5: https://lore.kernel.org/lkml/cover.1710473712.git.perry.yuan@xxxxxxx/
v6: https://lore.kernel.org/lkml/cover.1710754236.git.perry.yuan@xxxxxxx/
v7: https://lore.kernel.org/lkml/cover.1713861200.git.perry.yuan@xxxxxxx/
v8: https://lore.kernel.org/lkml/cover.1714112854.git.perry.yuan@xxxxxxx/

Perry Yuan (7):
cpufreq: acpi: move MSR_K7_HWCR_CPB_DIS_BIT into msr-index.h
cpufreq: amd-pstate: initialize new core precision boost state
cpufreq: amd-pstate: implement cpb_boost sysfs entry for boost control
cpufreq: amd-pstate: fix the MSR highest perf will be reset issue
while cpb boost off
Documentation: cpufreq: amd-pstate: introduce the new cpu boost
control method
cpufreq: amd-pstate: introduce per CPU frequency boost control
Documentation: cpufreq: amd-pstate: update doc for Per CPU boost
control method

Documentation/admin-guide/pm/amd-pstate.rst | 31 ++++
arch/x86/include/asm/msr-index.h | 2 +
drivers/cpufreq/acpi-cpufreq.c | 2 -
drivers/cpufreq/amd-pstate-ut.c | 2 +-
drivers/cpufreq/amd-pstate.c | 189 ++++++++++++++++++--
include/linux/amd-pstate.h | 14 ++
6 files changed, 226 insertions(+), 14 deletions(-)

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2.34.1