https://wiki.linaro.org/projects/big.LITTLE.MP
Work Items for functional completion: https://wiki.linaro.org/projects/big.LITTLE.MP/WorkItems
Roadmap Cards:
Epic big.LITTLE MP card - http://cards.linaro.org/browse/CARD-190
The card is being reworked to split the work that is completed and the ongoing/to be done one. Proposal to be presented to TSC.
Main Project page: https://launchpad.net/linaro-big-little-system
Development ============
1. big.LITTLE IKS
Current IKS snapshot: git://git.linaro.org/landing-teams/working/arm/kernel.git
More information: http://lists.linaro.org/pipermail/linaro-dev/2013-May/015882.html
2. big.LITTLE MP
There are two branches, which are functionally equivalent - they tweak the scheduler to select the right processes to move to the A15 and try to decrease power consumption while maintaining performance.
* A Reference (stable) big.LITTLE MP patchset (merged with linux-linaro):
https://git.linaro.org/gitweb?p=arm/big.LITTLE/mp.git%3Ba=shortlog%3Bh=refs/...
Recommended to be used for testing. Expecting few bugfixes to be integrated for this cycle.
* And an upstream (work in progress) big.LITTLE MP patchset:
https://git.linaro.org/gitweb?p=arm/big.LITTLE/mp.git%3Ba=shortlog%3Bh=refs/...
Being worked on in order to achieve the performance/power numbers of the reference one.
* Documentation:
Code flow is already covered by several LWN articles. See https://wiki.linaro.org/WorkingGroups/PowerManagement/Doc/ in the Articles section. We will provide a tuning guide once we have reached agreement upstream.
* Automated benchmarking code is ready:
- A python script to download LAVA bundle and extract results and populate results on to given Google spreadsheet was created.
- Discussions are still going on, but it’s very close to completion.
Blueprint Updates ------------------
* https://blueprints.launchpad.net/linaro-big-little-system/+spec/big-little-m...
Ongoing work.
* https://blueprints.launchpad.net/linaro-big-little-system/+spec/small-task-p...
- Results from an 80-core machine received, analyzing.
- New version based on last comments (update more often) is being prepared.
* https://blueprints.launchpad.net/linaro-big-little-system/+spec/cpu-hot-plug...
- Switch to Python for scripting to support floating point calculations.
- Discussions ongoing on the target latency value for the test (as the latency depends on the load).
* https://blueprints.launchpad.net/linaro-big-little-system/+spec/sched-cooper...
- Long-lasting BP (6+ month to get something), no updates.
QA ==
* https://blueprints.launchpad.net/linaro-qa/+spec/prepare-iks-testing-code-to...
- Inprogress. - Need to be tested on Samsung board.
big.LITTLE MP LAVA Dashboard http://validation.linaro.org/lava-server/dashboard/image-reports/linaro-andr...
Testing (week 19):
sched_tests.git #Cases #Run Pass Fail Absolute pass rate Regression 20 19 19 0 100 % mpbasicsuite 14 10 10 0 100 % mpcoresuite 10 6 6 0 100 % mpextendedsuite 20 10 7 3 70 % mploadbalance 2 2 2 0 100 %
http://lists.linaro.org/pipermail/linaro-dev/2013-May/015923.html
Bugs: https://bugs.launchpad.net/linaro-big-little-system/+bugs?field.tag=bl-mp
Highlight: Bug 1166246 - Lockup on post 3.9 IKS kernel
- bisected the problem to a single patch, investigating. - takes about 20 hours to reproduce. - setting up a dedicated board for long term testing.