Messages in this thread | | | Date | Mon, 9 Jun 2014 09:22:49 -0400 (EDT) | From | Nicolas Pitre <> | Subject | Re: [RFC PATCH 06/16] arm: topology: Define TC2 sched energy and provide it to scheduler |
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On Mon, 9 Jun 2014, Morten Rasmussen wrote:
> On Sat, Jun 07, 2014 at 03:33:58AM +0100, Nicolas Pitre wrote: > > On Fri, 6 Jun 2014, Ingo Molnar wrote: > > > > > In any case, even with turbo frequencies, switching power use is > > > probably an order of magnitude higher than leakage current power use, > > > on any marketable chip, so we should concentrate on being able to > > > cover this first order effect (P/work ~ V^2), before considering any > > > second order effects (leakage current). > > > > Just so that people are aware... We'll have to introduce thermal > > constraint management into the scheduler mix as well at some point. > > Right now what we have is an ad hoc subsystem that simply monitors > > temperature and apply crude cooling strategies when some thresholds are > > met. But a better strategy would imply thermal "provisioning". > > There is already work going on to improve thermal management: > > http://lwn.net/Articles/599598/ > > The proposal is based on power/energy models (too). The goal is to > allocate power intelligently based on performance requirements.
Ah, great! I missed that.
> While it is related to energy-aware scheduling and I fully agree that it > is something we need to consider, I think it is worth developing the two > ideas in parallel and look at sharing things like the power model later > once things mature. Energy-aware scheduling is complex enough on its > own to keep us entertained for a while :-)
Absolutely. This is why I said "at some point".
Nicolas
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