RE: [PATCH V10 0/7] amd-pstate preferred core

[Meng, Li (Jassmine)]

[AMD Official Use Only - General]

Hi all:
Do you have any other review comments?

Hi Rafael：
If there are no other issues, can you merge it to linux-next?


> -----Original Message-----
> From: Meng, Li (Jassmine) <Li.Meng@xxxxxxx>
> Sent: Monday, October 30, 2023 2:34 PM
> To: Rafael J . Wysocki <rafael.j.wysocki@xxxxxxxxx>; Huang, Ray
> <Ray.Huang@xxxxxxx>
> Cc: linux-pm@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> x86@xxxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx; Shuah Khan
> <skhan@xxxxxxxxxxxxxxxxxxx>; linux-kselftest@xxxxxxxxxxxxxxx; Fontenot,
> Nathan <Nathan.Fontenot@xxxxxxx>; Sharma, Deepak
> <Deepak.Sharma@xxxxxxx>; Deucher, Alexander
> <Alexander.Deucher@xxxxxxx>; Limonciello, Mario
> <Mario.Limonciello@xxxxxxx>; Huang, Shimmer
> <Shimmer.Huang@xxxxxxx>; Yuan, Perry <Perry.Yuan@xxxxxxx>; Du,
> Xiaojian <Xiaojian.Du@xxxxxxx>; Viresh Kumar <viresh.kumar@xxxxxxxxxx>;
> Borislav Petkov <bp@xxxxxxxxx>; Oleksandr Natalenko
> <oleksandr@xxxxxxxxxxxxxx>; Meng, Li (Jassmine) <Li.Meng@xxxxxxx>
> Subject: [PATCH V10 0/7] amd-pstate preferred core
>
> Hi all:
>
> The core frequency is subjected to the process variation in semiconductors.
> Not all cores are able to reach the maximum frequency respecting the
> infrastructure limits. Consequently, AMD has redefined the concept of
> maximum frequency of a part. This means that a fraction of cores can reach
> maximum frequency. To find the best process scheduling policy for a given
> scenario, OS needs to know the core ordering informed by the platform
> through highest performance capability register of the CPPC interface.
>
> Earlier implementations of amd-pstate preferred core only support a static
> core ranking and targeted performance. Now it has the ability to dynamically
> change the preferred core based on the workload and platform conditions
> and accounting for thermals and aging.
>
> Amd-pstate driver utilizes the functions and data structures provided by the
> ITMT architecture to enable the scheduler to favor scheduling on cores which
> can be get a higher frequency with lower voltage.
> We call it amd-pstate preferred core.
>
> Here sched_set_itmt_core_prio() is called to set priorities and
> sched_set_itmt_support() is called to enable ITMT feature.
> Amd-pstate driver uses the highest performance value to indicate the
> priority of CPU. The higher value has a higher priority.
>
> Amd-pstate driver will provide an initial core ordering at boot time.
> It relies on the CPPC interface to communicate the core ranking to the
> operating system and scheduler to make sure that OS is choosing the cores
> with highest performance firstly for scheduling the process. When amd-
> pstate driver receives a message with the highest performance change, it will
> update the core ranking.
>
> Changes from V9->V10:
> - cpufreq: amd-pstate:
> - - add judgement for highest_perf. When it is less than 255, the
>   preferred core feature is enabled. And it will set the priority.
> - - deleset "static u32 max_highest_perf" etc, because amd p-state
>   perferred coe does not require specail process for hotpulg.
>
> Changes form V8->V9:
> - all:
> - - pick up Tested-By flag added by Oleksandr.
> - cpufreq: amd-pstate:
> - - pick up Review-By flag added by Wyes.
> - - ignore modification of bug.
> - - add a attribute of prefcore_ranking.
> - - modify data type conversion from u32 to int.
> - Documentation: amd-pstate:
> - - pick up Review-By flag added by Wyes.
>
> Changes form V7->V8:
> - all:
> - - pick up Review-By flag added by Mario and Ray.
> - cpufreq: amd-pstate:
> - - use hw_prefcore embeds into cpudata structure.
> - - delete preferred core init from cpu online/off.
>
> Changes form V6->V7:
> - x86:
> - - Modify kconfig about X86_AMD_PSTATE.
> - cpufreq: amd-pstate:
> - - modify incorrect comments about scheduler_work().
> - - convert highest_perf data type.
> - - modify preferred core init when cpu init and online.
> - acpi: cppc:
> - - modify link of CPPC highest performance.
> - cpufreq:
> - - modify link of CPPC highest performance changed.
>
> Changes form V5->V6:
> - cpufreq: amd-pstate:
> - - modify the wrong tag order.
> - - modify warning about hw_prefcore sysfs attribute.
> - - delete duplicate comments.
> - - modify the variable name cppc_highest_perf to prefcore_ranking.
> - - modify judgment conditions for setting highest_perf.
> - - modify sysfs attribute for CPPC highest perf to pr_debug message.
> - Documentation: amd-pstate:
> - - modify warning: title underline too short.
>
> Changes form V4->V5:
> - cpufreq: amd-pstate:
> - - modify sysfs attribute for CPPC highest perf.
> - - modify warning about comments
> - - rebase linux-next
> - cpufreq:
> - - Moidfy warning about function declarations.
> - Documentation: amd-pstate:
> - - align with ``amd-pstat``
>
> Changes form V3->V4:
> - Documentation: amd-pstate:
> - - Modify inappropriate descriptions.
>
> Changes form V2->V3:
> - x86:
> - - Modify kconfig and description.
> - cpufreq: amd-pstate:
> - - Add Co-developed-by tag in commit message.
> - cpufreq:
> - - Modify commit message.
> - Documentation: amd-pstate:
> - - Modify inappropriate descriptions.
>
> Changes form V1->V2:
> - acpi: cppc:
> - - Add reference link.
> - cpufreq:
> - - Moidfy link error.
> - cpufreq: amd-pstate:
> - - Init the priorities of all online CPUs
> - - Use a single variable to represent the status of preferred core.
> - Documentation:
> - - Default enabled preferred core.
> - Documentation: amd-pstate:
> - - Modify inappropriate descriptions.
> - - Default enabled preferred core.
> - - Use a single variable to represent the status of preferred core.
>
> Meng Li (7):
>   x86: Drop CPU_SUP_INTEL from SCHED_MC_PRIO for the expansion.
>   acpi: cppc: Add get the highest performance cppc control
>   cpufreq: amd-pstate: Enable amd-pstate preferred core supporting.
>   cpufreq: Add a notification message that the highest perf has changed
>   cpufreq: amd-pstate: Update amd-pstate preferred core ranking
>     dynamically
>   Documentation: amd-pstate: introduce amd-pstate preferred core
>   Documentation: introduce amd-pstate preferrd core mode kernel
> command
>     line options
>
>  .../admin-guide/kernel-parameters.txt         |   5 +
>  Documentation/admin-guide/pm/amd-pstate.rst   |  59 +++++-
>  arch/x86/Kconfig                              |   5 +-
>  drivers/acpi/cppc_acpi.c                      |  13 ++
>  drivers/acpi/processor_driver.c               |   6 +
>  drivers/cpufreq/amd-pstate.c                  | 187 ++++++++++++++++--
>  drivers/cpufreq/cpufreq.c                     |  13 ++
>  include/acpi/cppc_acpi.h                      |   5 +
>  include/linux/amd-pstate.h                    |  10 +
>  include/linux/cpufreq.h                       |   5 +
>  10 files changed, 288 insertions(+), 20 deletions(-)
>
> --
> 2.34.1