* A big.LITTLE MP integration tree has been created to help test the various patchsets together and it is being used for the TC2 enablement. ARM is going to point all members to this tree instead of hosting their own. * (git://git.linaro.org/arm/big.LITTLE/mp.git)
* The ARM Landing Team delivered support for ARM TC2 tile for the vexpress board. TC2 is a big.LITTLE core with 2 Cortex A15 and 3 Cortex a7 processors).
* The Linaro Power Management group delivered its first submissions of big.LITTLE MP functionality - improving hotplug and making it faster - minimal unoptimised support for MP in ARM (patches accepted by Russell, Vincent Guittot) - add support to cpuidle for MP (Daniel Lezcano, patches in review) - including minimal unoptimised support for MP in ARM, - support to cpuidle. - Asymetric ARM support patchset has been accepted upstream.
- Scripts to help emulate a b.L system in absence of HW * http://git.linaro.org/gitweb?p=people/rob_lee/asymm_cpu_emu.git%3Ba=summary)
* Vincent Guitot has run some tests to measure the improvement of the cpu plug duration with Tejun's patches. The results are available on this link: https://wiki.linaro.org/WorkingGroups/PowerManagement/Doc/Hotplug#Workqueue
Other items: * Thomas Gleixner released v3 of his smpboot patchset that will be the basis of getting rid of high-overhead per-CPU kthread creation. This version fixes the UP build error, but introduced an CONFIG_PREEMPT=y issue in softirq, which I am tracking down.
* Silas Boyd-Wickizer has prototyped a tool based on the Linux kernel's "sparse" static analysis software to classify the 300+ uses of for_each_online_cpu(), which will help us work out how to address any needed changes required to allow CPU hotplug to get rid of stop_machine().
* Paul McKenney's RCU changes to support CPU hotplug's getting rid of __stop_machine() are now in -tip slated for 3.6. I do expect that there are additional implicit RCU dependencies on __stop_machine(), and will be continuing inspection efforts to track them down.
* A number of CPU-hotplug improvements from a number of contributors are in -tip queued for 3.6 inclusion.
* Paul McKenney presented a work-in-progress poster session on the CPU-hotplug efforts (co-authored by Thomas Gleixner and Vincent Guittot) at ECRTS last week. Well received, particularly the real-time aspects.
* Paul McKenney will be leading a Linux Plumbers Conference discussion on this topic as part of Amit's and Vincent's Scheduler microconference.
* Paul Turner released a new version of his entity load-tracking patchset that Morten Rasmussen has been basing his scheduler changes on.