The Linux Plumbers 2012 Microconference - Constraint Framework track focuses on the identification of useful abstractions and possible designs of extensions to PM_QOS to deal with new constraint classes and operational limits to subsystem performance.
From a high level pm-constraints is a generalisation 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:
Anyone working in any of these areas or pm-qos applications are encouraged to participate in this micro-conference.
The micro-conference will be organised into extract the following 2 things from the participants:
Many developers of software stacks for SoC's are finding themselves needing to extend pm_qos to add new qos_classes for one-off boards or products. As pm_qos constraint classes get exposed to user mode, we need to make sure the abstractions we expose are portable across different SOC's, boards and ISA's. This is a high bar. Because of this we need some effort put toward identifying such constraint classes and we need to consider enabling kernel only constraint class extensions for one-off platform tweaks.
Mark Gross, initial writer of pm_qos, would like to lead this microconf.
When submitting a proposal for this track, use the prefix “lpc2012-cf-” for the “Name” field.
Additional participants and presentation proposals are very welcome subject to the constraints of the LPC planning folks.
As I review the talks I may ask for more focus on problem definitions / examples / use cases where constraints are needed and how the are used in your specific devices. If some topics are too similar I may request the respective parties to collaborate to consolidate talks or differentiate from each other a little. (TBD)
SHOULD NOT OVERLAP WITH FOLLOWING MICROCONF AREAS/TALKS:
If each sticks to the requested 20 min format then we are looking at 2hrs just to cover the presentations leaving 30 min to discuss.
We should to plan to hang out and have a working session to hash out some implementation ideas outside the micro conf after everyone gets a chance to express their problems and ideas. (maybe on a following day to give me a chance to document the discussions)
The expected output is to have a documented set of examples where pm constraints are needed and/or used with a representative set of interface and implementation requirements derived from the presentations and discussion. From this I hope a good implementation will follow naturally that most will be happy with.
This is a good place to record notes from your session. All too often, if notes were not written down, the session might as well not have happened.