On Tue, May 15, 2012 at 12:40 PM, Jean Pihet <jean.pihet@xxxxxxxxxxxxxx> wrote: > Hi! > > Here is my proposal for the PM constraints micro-conf RFP, as e-mailed today: > > Session title: A New Model for the System and Devices Latency > > Name of microconference (if applicable): PM constraints micro-conf, > led by Mark Gross > > Abstract: > Due to the nature of the new SoC architectures the Power Management > needs a new model for the various system latencies. The talk presents: > . the concepts of system, devices, wake-up and resume latencies, > . the recent changes in the devices framework for the latency, why > and how to make it generic, > . the link with the other PM QoS frameworks: thermal, cpuidle, Jean, Do you already consider GPU drivers, backlight drivers and battery charging for setting constraints (performance and thermal) ? Between your, Eduardo's and Antti's proposals, a lot of ground is being covered and I don't want to make a new proposal just for these three. But we're keen on helping consolidate on generic interfaces to deal with these three kinds of devices. > . the recent changes in the ARM/OMAP platform code for the system latency, > . the problems encountered while modelling and measuring the > various latencies, > > . a proposal on the model and on the way to implement it, > . the planned changes in the device framework, the platform code > and the APIs. > > This talk is oriented towards Linux power management developers. The > goal is to agree on a framework implementation and the interfaces > within the kernel and with the user space. > > Experience: > Jean Pihet, NewOldBits.com > > Jean Pihet is working with embedded Linux since many years now, for > companies like Texas Instruments, MontaVista, Motorola and Philips. > Recently NewOldBits.com has been founded to provide high quality > consulting services. The area of work is mainly OMAP Power Management, > tracing and profiling tools (perf, ftrace, oprofile...) for recent ARM > cores. > > Kind regards, > Jean > > On Tue, May 15, 2012 at 7:34 AM, Valentin, Eduardo > <eduardo.valentin@xxxxxx> wrote: >> FYI, >> >> I will submit later today, something like this: >> " >> Abstract >> >> The thermal challenge is to design an end-product with high >> performance while keeping the junction temperature of the IC >> components used on this product within their limitations and which >> does not present a thermal discomfort for the user. OMAP4/OMAP5 System >> on Chips, operating at highest Operating Performance Points (OPP), is >> a powerful mobile applications processor. However operating at higher >> voltage and higher frequency in a sustained manner may cause thermal >> limits to be exceeded, both for silicon and user comfort. We propose a >> new framework to model per device power constraints, for containment >> of thermal limitations across major heat sources of a end-product >> device, e.g. LCD, CPU, charging, etc. The framework shall facilitate >> the power and thermal management performed by governor and policies, >> depending on device context and use case knowledge. >> >> Authors >> >> Eduardo Valentin, System Software Engineer at Texas Instruments, >> working on OMAP Linux kernel, previously a working on power management >> in maemo for Nokia. >> >> >> On Tue, May 15, 2012 at 8:06 AM, Valentin, Eduardo >> <eduardo.valentin@xxxxxx> wrote: >>> Benoit, >>> >>> On Mon, May 14, 2012 at 8:11 PM, Cousson, Benoit <b-cousson@xxxxxx> wrote: >>>> Hi Jean, >>>> >>>> >>>> On 5/14/2012 2:45 PM, Jean Pihet wrote: >>>>> >>>>> Hi Benoit, >>>>> >>>>> On Fri, May 11, 2012 at 9:17 AM, Valentin, Eduardo >>>>> <eduardo.valentin@xxxxxx> wrote: >>>>>> >>>>>> Hello Mark, >>>>>> >>>>>> On Wed, May 2, 2012 at 5:36 PM, mark gross<markgross@xxxxxxxxxxx> wrote: >>>>>>> >>>>>>> This is a Request For Participation in a micro-conference at this years >>>>>>> Linux plumbers event. For this micro conference to happen we need to >>>>>>> reach a certain critical mass WRT participants as measured by submitted >>>>>>> talks associated to Power Management Constraints. >>>>>> >>>>>> >>>>>> Nice! Thanks for proposing this. >>>>>> >>>>>>> >>>>>>> The To: list is populated with folks that I've had interactions with >>>>>>> over extending pm-qos or constraint based PM over the past year. >>>>>>> >>>>>>> If you are working on problems related to constraining the power / >>>>>>> performance of devices I am inviting your participation and request you >>>>>>> submit a proposal for presenting your problem space (preferred) and or >>>>>>> solution to a group of developers looking for a good solution to push >>>>>>> upstream. The talks will be about 20 min long as I want to get into >>>>>>> some design and implementation discussions after the requirements >>>>>>> definition is mostly finished. >>>>> >>>>> Is it OK to submit a talk for the next LPC? The deadline is tomorrow IIRC. >>>> >>>> >>>> Yes, it is. Go ahead. It is related to Mark's proposal? Because it seems we >>>> have to do some homework in order to participate to the micro-conf :-(. >>> >>> Yes, the homework is required in order to drive the discussion based >>> on existing usable solutions.. >>> >>> Jean, I'll write down a proposal today, from thermal requirements >>> perspective. But we can discuss also a way to converge either in a >>> common presentation or in even with two presentations but with strong >>> linking together. >>> >>> Just trying to avoid two conflicting proposals from two peers @ti.com >>> >>>> >>>> Regards, >>>> Benoit >>>> >>>> >>>>> >>>>> Regards, >>>>> Jean >>>>> >>>>>>> >>>>>>> I am interested in gathering user mode interface needs as well as kernel >>>>>>> mode. >>>>>>> >>>>>>> From a high level pm-constraints is a generalization of pm-qos to >>>>>>> include >>>>>>> limiting performance as well as its current limiting of device >>>>>>> throttling. >>>>>>> >>>>>>> As performance limiting is typically used for any of the following: >>>>>>> 1) staying within thermal operational envelopes >>>>>>> 2) avoiding peak current >>>>>>> 3) extending battery life in active use cases >>>>>>> >>>>>>> I invite anyone working in any of these areas or pm-qos applications to >>>>>>> participate in this micro-conference. >>>>>>> >>>>>>> I will organize the micro-conference into 2 parts: >>>>>>> 1) problem statements with specific participant examples where >>>>>>> constraining the performance or throttling is needed. >>>>>> >>>>>> >>>>>> >>>>>> I could bring something on the use cases where this type of >>>>>> constraining could be used. Essentially major focus gets partitioned >>>>>> in two areas: For device skin/case temperature management, and IC's >>>>>> junction temperature management. >>>>>> >>>>>> I am currently checking the traveling arrangements as well. And >>>>>> confirming soon. >>>>>> >>>>>> >>>>>>> >>>>>>> 2) high level design brain storming. >>>>>>> >>>>>>> If the micro-conference happens (i.e. critical mass is reached) any >>>>>>> interested linux-plumbers attendees is very welcome to participate. >>>>>>> >>>>>>> Please send me an off list email if you want me to add you to my mutt >>>>>>> alias of interested parties I'll use to cc people on emails. Note: must >>>>>>> of the correspondence will cc linux-pm too. >>>>>>> >>>>>>> Please submit a proposal if you are interested in participating in this >>>>>>> with me. I know a number of people are working in this space for the >>>>>>> past few years now. I think its a good time to compare notes and at >>>>>>> least consolidate requirements and use cases. Perhaps we'll even come >>>>>>> up >>>>>>> with a good design to implement in the process. >>>>>>> >>>>>>> thanks, >>>>>>> --mark >>>>>>> >>>>>> >>>>>> >>>>>> All best, >>>>>> -- >>>>>> >>>>>> Eduardo Valentin >>>>>> _______________________________________________ >>>>>> linux-pm mailing list >>>>>> linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx >>>>>> https://lists.linuxfoundation.org/mailman/listinfo/linux-pm >>>> >>>> >>> >>> >>> >>> -- >>> >>> Eduardo Valentin >> >> >> >> -- >> >> Eduardo Valentin _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/linux-pm
