Re: [PATCH v6 0/6] AMD Pstate Driver Core Performance Boost

From: Gautham R. Shenoy
Date: Wed Mar 20 2024 - 05:44:17 EST


Hello Perry,

On Mon, Mar 18, 2024 at 06:11:07PM +0800, Perry Yuan wrote:
> 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"
>
> The legancy boost interface has been removed due to the function
> conflict with new cpb_boost which can support all modes.
>
> 1). enable core boost:

You meant disable core boost here.

> $ 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). disabble core boost:

.. and enable core boost here.

> $ 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 patches have been tested with the AMD 7950X processor and many users
> would like to get core boost control enabled for power saving.
>
> If you would like to test this patchset, it needs to apply the patchset
> based on below one latest version patchset.
> https://lore.kernel.org/lkml/cover.1710754409.git.perry.yuan@xxxxxxx/

Thanks. Will test this on EPYC platforms.
>
> Perry.

--
Thanks and Regards
gautham.

>
> 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/
>
>
> Perry Yuan (6):
> 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-ut: support new cpb boost control interface
>
> Documentation/admin-guide/pm/amd-pstate.rst | 11 ++
> 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 | 143 ++++++++++++++++++--
> include/linux/amd-pstate.h | 13 ++
> 6 files changed, 160 insertions(+), 13 deletions(-)
>
> --
> 2.34.1
>