On 13/06/2018 22:32, Pandruvada, Srinivas wrote: > On Wed, 2018-06-13 at 22:19 +0200, Daniel Lezcano wrote: >> On 13/06/2018 22:07, Pandruvada, Srinivas wrote: >>> On Wed, 2018-06-13 at 22:00 +0200, Daniel Lezcano wrote: >>>> On 13/06/2018 17:54, Pandruvada, Srinivas wrote: >>>>> On Tue, 2018-06-12 at 14:00 +0200, Daniel Lezcano wrote: >>>>>> Initially, the cpu_cooling device for ARM was changed by >>>>>> adding a >>>>>> new >>>>>> policy inserting idle cycles. The intel_powerclamp driver >>>>>> does a >>>>>> similar action. >>>>>> >>>>>> Instead of implementing idle injections privately in the >>>>>> cpu_cooling >>>>>> device, move the idle injection code in a dedicated framework >>>>>> and >>>>>> give >>>>>> the opportunity to other frameworks to make use of it. >>>>>> >>>>>> The framework relies on the smpboot kthreads which handles >>>>>> via >>>>>> its >>>>>> main loop the common code for hotplugging and [un]parking. >>>>>> >>>>>> This code was previously tested with the cpu cooling device >>>>>> and >>>>>> went >>>>>> through several iterations. It results now in split code and >>>>>> API >>>>>> exported in the header file. It was tested with the cpu >>>>>> cooling >>>>>> device >>>>>> with success. >>>>>> >>>>> >>>>> May be I have missed, but I don't see any use of powercap >>>>> sysfs. >>>>> >>>>> We created powercap sys that user space is presented a common >>>>> interface >>>>> for power capping. The RAPL driver was also submitted as >>>>> cooling >>>>> device >>>>> before, but suggestion was to create this powercap. >>>>> >>>>> So if powercap interface is not enough then may be we should >>>>> enhance >>>>> that. >>>> >>>> We are creating a framework for idle injection. This framework >>>> can >>>> then >>>> be used by the cpu_cooling device, the power_clamp and in >>>> addition a >>>> power capping for ARM (if it makes sense). >>> >>> But in this case, why in drivers/powercap folder as this is another >>> framework? >> >> I presented at OSPM 2nd the cpu idle cooling device. It is ARM >> specific >> but has some similarities with the power clamp driver. >> >> Some board come with power numbers defined in their DT and from there >> we >> are able to compute a targeted power by injecting idle cycles. >> >> As the idle injection allows to do also power capping, Rafael told me >> to >> move that to a framework (may be better say a component with exported >> services or library) and put it in drivers/powercap. > So Rafael wants it to be in powercap.
That is what I understood. -- <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | <http://twitter.com/#!/linaroorg> Twitter | <http://www.linaro.org/linaro-blog/> Blog