[RFC v02 0/5] Power Capping Framework and RAPL Driver

[RFC v02 0/5] Power Capping Framework and RAPL Driver

[Srinivas Pandruvada]

This series was sent to Linux kernel mailing list on August 7th, 2013.
Posting to Linux PM mailing list for wider audience, without any change.


Overview
With the evolution of technologies, which enables power monitoring and limiting,
more and more devices are able to constrain their power consumption under certain
limits. There are several use cases for such technologies:
- Power monitoring: Each device can report its power consumption.
- Power Limiting: Setting power limits on the devices allows users to guard against
platform reaching max system power level.
- Maximize performance: While staying below a power limit, it allows devices to
automatically adjust performance to meet demands
- Dynamic control and re-budgeting: If each device can be constrained to some power,
extra power can redistributed to other devices, which needs additional performance.

One such example of technology is RAPL (Running Average Power Limit) mechanism
available in the latest Intel Processors. Intel is slowly adding many devices under
RAPL control. Also there are other technologies available, for power capping various
devices. Soon it is very likely that other vendors are also adding or considering
such implementation.

Power Capping framework is an effort to have a uniform interface available to Linux
drivers, which will enable
- A uniform sysfs interface for all devices which can offer power capping
- A common API for drivers, which will avoid code duplication and easy
implementation of client drivers.

Also submitting Intel RAPL driver using power capping framework.


Revisions:
v02:
Sign-offs and reviewed-by tags
Stylistic issues suggested by Joe Perches
Removed "counter" from power_uw documentation as pointed by Jonathan Corbet
Submitting Intel RAPL driver using power capping framework

v01:
Use device model only to register zones and controllers.

v00:
Presented options

Jacob Pan (2):
  x86/msr: add 64bit _on_cpu access functions
  Introduce Intel RAPL power capping driver

Srinivas Pandruvada (3):
  PowerCap: Documentation
  PowerCap: Add class driver
  PowerCap: Added to drivers build

 Documentation/ABI/testing/sysfs-class-powercap   |  165 +++
 Documentation/powercap/PowerCappingFramework.txt |  686 ++++++++++++
 arch/x86/include/asm/msr.h                       |   22 +
 arch/x86/lib/msr-smp.c                           |   62 +
 drivers/Kconfig                                  |    2 +
 drivers/Makefile                                 |    1 +
 drivers/powercap/Kconfig                         |   24 +
 drivers/powercap/Makefile                        |    6 +
 drivers/powercap/intel_rapl.c                    | 1305 ++++++++++++++++++++++
 drivers/powercap/powercap_sys.c                  |  995 +++++++++++++++++
 include/linux/powercap.h                         |  300 +++++
 11 files changed, 3568 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-class-powercap
 create mode 100644 Documentation/powercap/PowerCappingFramework.txt
 create mode 100644 drivers/powercap/Kconfig
 create mode 100644 drivers/powercap/Makefile
 create mode 100644 drivers/powercap/intel_rapl.c
 create mode 100644 drivers/powercap/powercap_sys.c
 create mode 100644 include/linux/powercap.h

-- 
1.8.3.1

Re: [RFC v02 0/5] Power Capping Framework and RAPL Driver

[Srinivas Pandruvada]

On 08/07/2013 09:12 AM, Srinivas Pandruvada wrote:
> Overview
> With the evolution of technologies, which enables power monitoring and limiting,
> more and more devices are able to constrain their power consumption under certain
> limits. There are several use cases for such technologies:
> - Power monitoring: Each device can report its power consumption.
> - Power Limiting: Setting power limits on the devices allows users to guard against
> platform reaching max system power level.
> - Maximize performance: While staying below a power limit, it allows devices to
> automatically adjust performance to meet demands
> - Dynamic control and re-budgeting: If each device can be constrained to some power,
> extra power can redistributed to other devices, which needs additional performance.
>
> One such example of technology is RAPL (Running Average Power Limit) mechanism
> available in the latest Intel Processors. Intel is slowly adding many devices under
> RAPL control. Also there are other technologies available, for power capping various
> devices. Soon it is very likely that other vendors are also adding or considering
> such implementation.
>
> Power Capping framework is an effort to have a uniform interface available to Linux
> drivers, which will enable
> - A uniform sysfs interface for all devices which can offer power capping
> - A common API for drivers, which will avoid code duplication and easy
> implementation of client drivers.
>
> Also submitting Intel RAPL driver using power capping framework.
>
>
> Revisions:
Thanks for everyone for review. I have received enough negative 
comments, which will require another version.
So please hold off your reviews till next version.

> v02:
> Sign-offs and reviewed-by tags
> Stylistic issues suggested by Joe Perches
> Removed "counter" from power_uw documentation as pointed by Jonathan Corbet
> Submitting Intel RAPL driver using power capping framework
>
> v01:
> Use device model only to register zones and controllers.
>
> v00:
> Presented options
>
> Jacob Pan (2):
>    x86/msr: add 64bit _on_cpu access functions
>    Introduce Intel RAPL power capping driver
>
> Srinivas Pandruvada (3):
>    PowerCap: Documentation
>    PowerCap: Add class driver
>    PowerCap: Added to drivers build
>
>   Documentation/ABI/testing/sysfs-class-powercap   |  165 +++
>   Documentation/powercap/PowerCappingFramework.txt |  686 ++++++++++++
>   arch/x86/include/asm/msr.h                       |   22 +
>   arch/x86/lib/msr-smp.c                           |   62 +
>   drivers/Kconfig                                  |    2 +
>   drivers/Makefile                                 |    1 +
>   drivers/powercap/Kconfig                         |   24 +
>   drivers/powercap/Makefile                        |    6 +
>   drivers/powercap/intel_rapl.c                    | 1305 ++++++++++++++++++++++
>   drivers/powercap/powercap_sys.c                  |  995 +++++++++++++++++
>   include/linux/powercap.h                         |  300 +++++
>   11 files changed, 3568 insertions(+)
>   create mode 100644 Documentation/ABI/testing/sysfs-class-powercap
>   create mode 100644 Documentation/powercap/PowerCappingFramework.txt
>   create mode 100644 drivers/powercap/Kconfig
>   create mode 100644 drivers/powercap/Makefile
>   create mode 100644 drivers/powercap/intel_rapl.c
>   create mode 100644 drivers/powercap/powercap_sys.c
>   create mode 100644 include/linux/powercap.h
>