4.5 VRQ test patch v4.5_0469_test0 released

This is the first test patch branch for v4.5 kernel, it's totally based on the  v4.5_0469_vrq0 code, and include only one change.

The change is a continuous improvement for the "sticky task". For the background information about "sticky task", please read about this from CK's blog or search "sticky" in CK's blog for further information.

In VRQ, the sticky task already has some modifications, which happened with the policy caching timeout changes, please reference this blog for information. In this change, I'm trying *not* putting sticky task into grq, instead, the sticky task is now set as the preempt task of the rq, which will be selected to be run immediately when next reschedule comes.

Pros:
This change reduce grq locking access overhead for all workload especially the for heavy load, it is recorded 2m32.xxxs under 300% workload compare to the original 2m36.xxxs for the NORMAL policy tasks.

Cons:
Theoretically, in current implement, two task A and B which run on same cpu could be the running task and the sticky task rationally and fail to select other tasks in the running queue.


The test branch is now at bitbucket and github, have fun with this first test branch and your feedback will be welcome.

BR Alfred

4.5 VRQ patch v4.5_0469_vrq0 released

Here comes the all in one vrq patch v4.5_0469_vrq0 which now is based on the latest BFS 0469, of course the new sched_interactive design in the latest BFS has been removed and be replaced by the task policy based caching timeout design in VRQ.

Basically, this release doesn't introduce much code changes comparing to the previous release, just put the code based on the latest BFS for better maintenance in the future.

As usual, I'm still waiting the upstream BFQ patch for 4.5 to update the GIT repositories. If you have any question/feedback about the VRQ patch, please let me know.

Have fun with this new release!

BR Alfred

Edit:
I have pushed the latest vrq0 code to my repository on bitbucket and github. Individual commit can be viewed now.

4.5 VRQ patch v4.5_0466_vrq0 released

Finally, here is the all in one patch file at download link for vrq patch for kernel 4.5. Git repository will be updated in next two days.

It's still based on bfs 0466, and as previous branch strategy change, it contains no new code changes but the 4.5 sync-up code. And as CK has released 0469 but it is said that there is no code changes upon 0467 expect the sync-up code. I would check and pick up useful changes in 0469 to the incoming vrq1 release.

Have fun with 4.5 kernel.

BR Alfred