Re: [PATCH v2] Introduce Intel RAPL cooling device driver

From: Greg Kroah-Hartman
Date: Fri Apr 05 2013 - 17:06:55 EST


On Fri, Apr 05, 2013 at 02:02:04PM -0700, Jacob Pan wrote:
> RAPL(Running Average Power Limit) interface provides platform software
> with the ability to monitor, control, and get notifications on SOC
> power consumptions. Since its first appearance on Sandy Bridge, more
> features have being added to extend its usage. In RAPL, platforms are
> divided into domains for fine grained control. These domains include
> package, DRAM controller, CPU core (Power Plane 0), graphics uncore
> (power plane 1), etc.
>
> The purpose of this driver is to expose RAPL for userspace
> consumption. Overall, RAPL fits in the generic thermal layer in
> that platform level power capping and monitoring are mainly used for
> thermal management and thermal layer provides the abstracted interface
> needed to have portable applications.
>
> Specifically, userspace is presented with per domain cooling device
> with sysfs links to its true device. Although RAPL domain provides many
> parameters for fine tuning, long term power limit is exposed as the
> single knob via cooling device state. Whereas the rest of the
> parameters are still accessible via the linked RAPL class devices.
> This interface allows both simple and advanced use cases.
>
> Eventfd is used to provide notifications to the userspace. At per domain
> level, use can choose any event capable parameters to register for
> threshold crossing notifications. This is shamelessly "borrowed" from
> cgroup with some trimming/fitting.
>
> Zhang, Rui's initial RAPL driver was used as a reference and starting
> point. Many thanks.
> https://lkml.org/lkml/2011/5/26/93
>
> Unlike the patch above, which is mainly for monitoring, this driver
> focus on the control and usability by user applications.
>
> Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>

As described in the cover letter response:
NACKed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

please redo this based on those comments.

greg k-h
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