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
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.
* 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:
- Workload results automated upload is being worked on.
Blueprint Updates ------------------
* https://blueprints.launchpad.net/linaro-big-little-system/+spec/big-little-m...
Should be much simpler now.
* https://blueprints.launchpad.net/linaro-big-little-system/+spec/cpuidle-add-...
Done.
* https://blueprints.launchpad.net/linaro-big-little-system/+spec/small-task-p...
Discussion is ongoing in ML.
Testing on a 64 core x86 system is ongoing, results to be available in the next report.
* https://blueprints.launchpad.net/linaro-big-little-system/+spec/cpu-hot-plug...
Unlocked last week. Discussions around data extraction are ongoing.
* https://blueprints.launchpad.net/linaro-big-little-system/+spec/sched-cooper...
Long-lasting BP (6+ month to get something), no updates.
QA ==
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
- isolated the problem (both A15 CPUs suspended by cpuidle, upon returning the status is not hitting the RAM). - cpuidle is a prerequisite for this issue to happen. - lockup is happening 800+ GHz, lower frequencies are being tested. - Dave Martin has a script that triggers the issue easily. - analysis is ongoing.