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

[Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>]

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
>