[RFC,V2,0/2] cpufreq: cppc: Add support for frequency invariance

Message ID cover.1608030508.git.viresh.kumar@linaro.org
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  • cpufreq: cppc: Add support for frequency invariance
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Viresh Kumar Dec. 15, 2020, 11:16 a.m.
Hello,

CPPC cpufreq driver is used for ARM servers and this patch series tries
to provide frequency invariance support for them.

This is tested with some hacks, as I didn't have access to the right
hardware, on the ARM64 hikey board to check the overall functionality
and that works fine.

Ionela/Peter Puhov, it would be nice if you guys can give this a shot.

This is based of pm/linux-next and patches [1] and [2] which I sent
recently to cleanup arm64 topology stuff.

Changes since V1:
- The interface for setting the callbacks is improved, so different
  parts looking to provide their callbacks don't need to think about
  each other.

- Moved to per-cpu storage for storing the callback related data, AMU
  counters have higher priority with this.

--
viresh

[1] https://lore.kernel.org/lkml/7a171f710cdc0f808a2bfbd7db839c0d265527e7.1607579234.git.viresh.kumar@linaro.org/
[2] https://lore.kernel.org/lkml/5ffc7b9ed03c6301ac2f710f609282959491b526.1608010334.git.viresh.kumar@linaro.org/

Viresh Kumar (2):
  topology: Allow multiple entities to provide sched_freq_tick()
    callback
  cpufreq: cppc: Add support for frequency invariance

 arch/arm64/include/asm/topology.h |   8 +-
 arch/arm64/kernel/topology.c      |  89 +++++++++----------
 drivers/base/arch_topology.c      |  56 +++++++++++-
 drivers/cpufreq/cppc_cpufreq.c    | 140 +++++++++++++++++++++++++++++-
 include/linux/arch_topology.h     |  14 ++-
 kernel/sched/core.c               |   1 +
 6 files changed, 244 insertions(+), 64 deletions(-)

-- 
2.25.0.rc1.19.g042ed3e048af

Comments

Ionela Voinescu Dec. 16, 2020, 7:50 p.m. | #1
Hi,

On Tuesday 15 Dec 2020 at 16:46:34 (+0530), Viresh Kumar wrote:
> Hello,

> 

> CPPC cpufreq driver is used for ARM servers and this patch series tries

> to provide frequency invariance support for them.

> 


Nitpick: cppc_cpufreq already supports cpufreq-based frequency
invariance, but not counter-based frequency invariance, when lacking
AMUs :).

> This is tested with some hacks, as I didn't have access to the right

> hardware, on the ARM64 hikey board to check the overall functionality

> and that works fine.

> 

> Ionela/Peter Puhov, it would be nice if you guys can give this a shot.

> 


I'll be on holiday starting tomorrow until January. I fully intend to
review and test this but I'll have to set myself a deadline for January
to do it.

Sorry for the delay,
Ionela.

> This is based of pm/linux-next and patches [1] and [2] which I sent

> recently to cleanup arm64 topology stuff.

> 

> Changes since V1:

> - The interface for setting the callbacks is improved, so different

>   parts looking to provide their callbacks don't need to think about

>   each other.

> 

> - Moved to per-cpu storage for storing the callback related data, AMU

>   counters have higher priority with this.

> 

> --

> viresh

> 

> [1] https://lore.kernel.org/lkml/7a171f710cdc0f808a2bfbd7db839c0d265527e7.1607579234.git.viresh.kumar@linaro.org/

> [2] https://lore.kernel.org/lkml/5ffc7b9ed03c6301ac2f710f609282959491b526.1608010334.git.viresh.kumar@linaro.org/

> 

> Viresh Kumar (2):

>   topology: Allow multiple entities to provide sched_freq_tick()

>     callback

>   cpufreq: cppc: Add support for frequency invariance

> 

>  arch/arm64/include/asm/topology.h |   8 +-

>  arch/arm64/kernel/topology.c      |  89 +++++++++----------

>  drivers/base/arch_topology.c      |  56 +++++++++++-

>  drivers/cpufreq/cppc_cpufreq.c    | 140 +++++++++++++++++++++++++++++-

>  include/linux/arch_topology.h     |  14 ++-

>  kernel/sched/core.c               |   1 +

>  6 files changed, 244 insertions(+), 64 deletions(-)

> 

> -- 

> 2.25.0.rc1.19.g042ed3e048af

>