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[v6,0/7] consolidate and cleanup CPU capacity

Message ID 20231109101438.1139696-1-vincent.guittot@linaro.org
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Series consolidate and cleanup CPU capacity | expand

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Vincent Guittot Nov. 9, 2023, 10:14 a.m. UTC
This is the 1st part of consolidating how the max compute capacity is
used in the scheduler and how we calculate the frequency for a level of
utilization.

Fix some unconsistancy when computing frequency for an utilization. There
can be a mismatch between energy model and schedutil.

Next step will be to make a difference between the original
max compute capacity of a CPU and what is currently available when
there is a capping applying forever (i.e. seconds or more).

Changes since v5:
- remove useless return in freq_inv_set_max_ratio()
- Add tags

Changes since v4:
- Capitalize the verb in subject
- Remove usless parentheses in cppc_get_dmi_max_khz()
- Use freq_ref pattern everywhere
- Fix MHz / kHz units conversion for cppc_cpufreq
- Move default definition of arch_scale_freq_ref() in
  include/linux/sched/topology.h beside arch_scale_cpu_capacity
  which faces similar default declaration behavior. This location covers
  all cases with arch and CONFIG_* which was not the case with previous
  attempts.

Changes since v3:
- Split patch 5 cpufreq/cppc
- Fix topology_init_cpu_capacity_cppc() 
- Fix init if AMU ratio
- Added some tags

Changes since v2:
- Remove the 1st patch which has been queued in tip
- Rework how to initialize the reference frequency for cppc_cpufreq and
  change topology_init_cpu_capacity_cppc() to also set capacity_ref_freq
- Add a RFC to convert AMU to use arch_scale_freq_ref and move the config
  of the AMU ratio to be done when intializing cpu capacity and
  capacity_ref_freq
- Added some tags

Changes since v1:
- Fix typos
- Added changes in cpufreq to use arch_scale_freq_ref() when calling
  arch_set_freq_scale (patch 3).
- arch_scale_freq_ref() is always defined and returns 0 (as proposed
  by Ionela) when not defined by the arch. This simplifies the code with
  the addition of patch 3.
- Simplify Energy Model which always uses arch_scale_freq_ref(). The
  latter returns 0 when not defined by arch instead of last item of the 
  perf domain. This is not a problem because the function is only defined
  for compilation purpose in this case and we don't care about the
  returned value. (patch 5)
- Added changes in cppc cpufreq to set capacity_ref_freq (patch 6)
- Added reviewed tag for patch 1 which got a minor change but not for
  others as I did some changes which could make previous reviewed tag
  no more relevant.

Vincent Guittot (7):
  topology: Add a new arch_scale_freq_reference
  cpufreq: Use the fixed and coherent frequency for scaling capacity
  cpufreq/schedutil: Use a fixed reference frequency
  energy_model: Use a fixed reference frequency
  cpufreq/cppc: Move and rename cppc_cpufreq_{perf_to_khz|khz_to_perf}
  cpufreq/cppc: Set the frequency used for computing the capacity
  arm64/amu: Use capacity_ref_freq to set AMU ratio

 arch/arm/include/asm/topology.h   |   1 +
 arch/arm64/include/asm/topology.h |   1 +
 arch/arm64/kernel/topology.c      |  26 +++---
 arch/riscv/include/asm/topology.h |   1 +
 drivers/acpi/cppc_acpi.c          | 104 ++++++++++++++++++++++
 drivers/base/arch_topology.c      |  56 ++++++++----
 drivers/cpufreq/cppc_cpufreq.c    | 139 ++++--------------------------
 drivers/cpufreq/cpufreq.c         |   4 +-
 include/acpi/cppc_acpi.h          |   2 +
 include/linux/arch_topology.h     |   8 ++
 include/linux/cpufreq.h           |   1 +
 include/linux/energy_model.h      |   6 +-
 include/linux/sched/topology.h    |   8 ++
 kernel/sched/cpufreq_schedutil.c  |  26 +++++-
 14 files changed, 224 insertions(+), 159 deletions(-)

Comments

Pierre Gondois Nov. 10, 2023, 8:30 a.m. UTC | #1
For a CPPC platform + EM/EAS (but without AMU):
Tested-by: Pierre Gondois <pierre.gondois@arm.com>

On 11/9/23 11:14, Vincent Guittot wrote:
> This is the 1st part of consolidating how the max compute capacity is
> used in the scheduler and how we calculate the frequency for a level of
> utilization.
> 
> Fix some unconsistancy when computing frequency for an utilization. There
> can be a mismatch between energy model and schedutil.
> 
> Next step will be to make a difference between the original
> max compute capacity of a CPU and what is currently available when
> there is a capping applying forever (i.e. seconds or more).
> 
> Changes since v5:
> - remove useless return in freq_inv_set_max_ratio()
> - Add tags
> 
> Changes since v4:
> - Capitalize the verb in subject
> - Remove usless parentheses in cppc_get_dmi_max_khz()
> - Use freq_ref pattern everywhere
> - Fix MHz / kHz units conversion for cppc_cpufreq
> - Move default definition of arch_scale_freq_ref() in
>    include/linux/sched/topology.h beside arch_scale_cpu_capacity
>    which faces similar default declaration behavior. This location covers
>    all cases with arch and CONFIG_* which was not the case with previous
>    attempts.
> 
> Changes since v3:
> - Split patch 5 cpufreq/cppc
> - Fix topology_init_cpu_capacity_cppc()
> - Fix init if AMU ratio
> - Added some tags
> 
> Changes since v2:
> - Remove the 1st patch which has been queued in tip
> - Rework how to initialize the reference frequency for cppc_cpufreq and
>    change topology_init_cpu_capacity_cppc() to also set capacity_ref_freq
> - Add a RFC to convert AMU to use arch_scale_freq_ref and move the config
>    of the AMU ratio to be done when intializing cpu capacity and
>    capacity_ref_freq
> - Added some tags
> 
> Changes since v1:
> - Fix typos
> - Added changes in cpufreq to use arch_scale_freq_ref() when calling
>    arch_set_freq_scale (patch 3).
> - arch_scale_freq_ref() is always defined and returns 0 (as proposed
>    by Ionela) when not defined by the arch. This simplifies the code with
>    the addition of patch 3.
> - Simplify Energy Model which always uses arch_scale_freq_ref(). The
>    latter returns 0 when not defined by arch instead of last item of the
>    perf domain. This is not a problem because the function is only defined
>    for compilation purpose in this case and we don't care about the
>    returned value. (patch 5)
> - Added changes in cppc cpufreq to set capacity_ref_freq (patch 6)
> - Added reviewed tag for patch 1 which got a minor change but not for
>    others as I did some changes which could make previous reviewed tag
>    no more relevant.
> 
> Vincent Guittot (7):
>    topology: Add a new arch_scale_freq_reference
>    cpufreq: Use the fixed and coherent frequency for scaling capacity
>    cpufreq/schedutil: Use a fixed reference frequency
>    energy_model: Use a fixed reference frequency
>    cpufreq/cppc: Move and rename cppc_cpufreq_{perf_to_khz|khz_to_perf}
>    cpufreq/cppc: Set the frequency used for computing the capacity
>    arm64/amu: Use capacity_ref_freq to set AMU ratio
> 
>   arch/arm/include/asm/topology.h   |   1 +
>   arch/arm64/include/asm/topology.h |   1 +
>   arch/arm64/kernel/topology.c      |  26 +++---
>   arch/riscv/include/asm/topology.h |   1 +
>   drivers/acpi/cppc_acpi.c          | 104 ++++++++++++++++++++++
>   drivers/base/arch_topology.c      |  56 ++++++++----
>   drivers/cpufreq/cppc_cpufreq.c    | 139 ++++--------------------------
>   drivers/cpufreq/cpufreq.c         |   4 +-
>   include/acpi/cppc_acpi.h          |   2 +
>   include/linux/arch_topology.h     |   8 ++
>   include/linux/cpufreq.h           |   1 +
>   include/linux/energy_model.h      |   6 +-
>   include/linux/sched/topology.h    |   8 ++
>   kernel/sched/cpufreq_schedutil.c  |  26 +++++-
>   14 files changed, 224 insertions(+), 159 deletions(-)
>
Viresh Kumar Nov. 10, 2023, 9:18 a.m. UTC | #2
On 09-11-23, 11:14, Vincent Guittot wrote:
> Save the frequency associated to the performance that has been used when
> initializing the capacity of CPUs.
> Also, cppc cpufreq driver can register an artificial energy model. In such
> case, it needs the frequency for this compute capacity.
> 
> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> Acked-by: Sudeep Holla <sudeep.holla@arm.com>
> ---
>  drivers/base/arch_topology.c | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>