The Agenda and the Minutes for this meeting can also be found at https://wiki.linaro.org/WorkingGroups/PowerManagement/Meetings/2010-07-28
Attendees : Amit Arora, Amit Kucheria, Bobby Bhatacharia, Srinivas Kalaga, Vishwanath Sripathy
Minutes: * Review action items from last meeting o ACTION: Bobby to investigate android contraints (e.g. display keep-alive) Will target it for the next week.
o ACTION: Srinivas to provide details of where he believes userspace - kernel interaction is required. pm_qos is low prio .. so this may take a few weeks for this action This may take a few weeks for this action. Currently at low priority (since pm_qos work is of low prio)
o ACTION: Srinivas to add ftrace item to task list and send patches to linaro Srinivas has been working on this in last few days. We should see something soon on this.
o ACTION: Amit K. to inform ARM about multi-core availability We are not getting any multi-core boards. Vishwa should have one. Now, the question is - will one board be enough ? Bobby to see possibility of getting more boards for Linaro. Not easy, but will consider the request open.
o ACTION: ARM to discuss giving out powertop tool ARM doesn't have a PowerTOP tool, so to speak, to give out. Though they have an Eclipse based tool, which is very much an ongoing work. Can work on making it available. But, no ETA as of now.
o ACTION: TI to elaborate on requirement of cpuidle instrumentation task Vishwa : The currently "known" c-states sleep time and latency information on OMAP boards are NOT optimal. There is a requirement for some kind of instrumentation to measure the s/w and the h/w latencies. Later is difficult part. And once we can get the optimal latencies, we will have to work on optimizing them. NEWACTION : Vishwa to create a blue print for this. It should mention the codepaths to be measured (eg. wakeup latencies, idle loop to idle loop latencies for various c-states) and other details.
o ACTION: ARM to share internal instrumentation flow (BAB: we might also align with Linaro on workload discussions) Bobby to make this available. But, it might take a couple of months.
* HW availability o Amit Arora is following up to expedite the process to acquire the development boards. May take some more time. o Vishwa has access to couple of OMAP3/4 SDP boards. Amit Kucheria mentioned that it may be a good idea to get the publically available boards, like the Beagleboards or the PANDA blades. Vishwa to find out about this. o Amit Kucheria has a Freescale i.mx51 babbage board and a beagleboard
* Git trees on git.linaro.org o We will have to host a couple of git trees in git.linaro.org o To start with, we may need two trees for the tools - for powertop and powerdebug (a new tool). o Need access to the host system and some process needs to be followed. o Once we start hosting the trees, we will have to send a mail to linaro-dev mailing list, requesting everyone to try out the code. o When we have patches for kernel, we may have to host a separate kernel git tree for Power Management, which should get merged with the linaro kernel git tree.
* gobby / ubuntu o Amit Kucheria recommended everyone to start using this tool, which is a cross-platform collaboration tool and will make things like taking minutes much easier (everyone will be able to contribute to it)
* Blueprint status o Tools blueprint : Amit Arora gave the update on the work he has been doing on powertop and powerdebug tools. He has a few patches ready, which he plans to host in a git tree. For the time being, we plan to host this code as tarballs at some location, which will help others to test it. o Master blueprint : Amit Kucheria had split the master blue print into "infrastructure" and "tools" blueprints. More such blueprints will need to be created as we go forward. o There are some known issues with Ondemand governor, which Vishwa and AmitK will take it to the the community (LKML/linux-pm and make sure to copy right people). Will need to share the constraints and ask for feedback on how its best to implement some of the things in the current framework.
* Others o Linaro's first released will be based on 2.6.35. Hence, all our work also should be inline to this release.
ACTION ITEMS:
Carried Forward from past : -------------------------
* CLOSED : o ACTION: TI to elaborate on requirement of cpuidle instrumentation task This has given birth to a new ACTION item, discussed below.
* ACTIVE : o ACTION: Bobby to investigate android contraints (e.g. display keep-alive) o ACTION: Srinivas to provide details of where he believes userspace - kernel interaction is required. o ACTION: Srinivas to add ftrace item to task list and send patches to linaro o ACTION: Amit K. to inform ARM about multi-core availability o ACTION: ARM to discuss giving out powertop tool
* DORMANT : o ACTION: ARM to share internal instrumentation flow (BAB: we might also align with Linaro on workload discussions) Might take couple of months.
New Items: --------- o ACTION: Vishwa to create a new blue print for the instrumentation of cpuidle related work o ACTION: Amit Arora to create tarballs of his current work and share it internally for testing o ACTION: Amit Kucheria and Vishwa to get inputs from community on the issues related to Ondemand governor.
Thanks! Amit Arora