MuQSS - The Multiple Queue Skiplist Scheduler v0.112

Here's an updated version of MuQSS.

 For 4.8.*:
4.8-sched-MuQSS_112.patch

 For 4.7.*:
4.7-sched-MuQSS_112.patch

Git tree here as 4.7-muqss or 4.8-muqss branches:
https://github.com/ckolivas/linux

It's getting close now to the point where it can replace BFS in -ck releases. Thanks to the many people testing and reporting back, some other misbehaviours were discovered and their associated fixes have been committed.

In particular,
- Balancing across CPUs was not looking at higher and lower scheduling policies correctly (SCHED_ISO, SCHED_IDLEPRIO and realtime policies)
- A serious stall/hang could happen with tasks using sched_yield (such as f@h client and numerous GPU drivers)
- Some minor accounting issues on new tasks with affinity set were fixed
- Overhead was further decreased on task selection
- Spurious preemption on CPUs where the preempted task had already gone are now avoided
- Spurious wakeup on CPUs that were assumed and are no longer idle are avoided
- A potential race in suspending to ram was fixed
- Old unused code from BFS was removed, along with unnecessary intermediate variables.
- Clean ups
- Some work towards actually documenting MuQSS in Documentation/scheduler/sched-MuQSS.txt was done, though incomplete.

Enjoy!
お楽しみ下さい
-ck

MuQSS - The Multiple Queue Skiplist Scheduler v0.111

Lots of bugfixes, lots of improvements, build fixes, you name it.

For 4.8:
4.8-sched-MuQSS_111.patch

For 4.7:
4.7-sched-MuQSS_111.patch

And in a complete departure from BFS, a git tree (which suits constant development like this, unlike BFS's stable release massive ports):

https://github.com/ckolivas/linux

Look in the pending/ directory to see all the patches that went into this or read the git changelog. In particular numerous warnings were fixed, throughput improved compared to 108, SCHED_ISO was rewritten for multiple queues, potential races/crashes were addressed, and build fixes for different configurations were committed.

I haven't been able to track the bizarre latency issues reported by runqlat and when I try to reproduce it myself I get nonsense values of latency greater than the history of the earth so I suspect an interface bug with BPF reporting values. It doesn't seem to affect actual latency in any way.

EDIT: Updated to version 0.111 which has a fix for suspend/resume.

Enjoy!
お楽しみ下さい
-ck