[Nexus 9 Original Android Development] bbedward:
The buck stops here

Project Background

This kernel makes things BETTER. Without tons and tons of over exaggerated fluff

"But BB...What about INTelligentSuperBOOSTXX5MillionPOINT5MegaBlast?!?!?!? Can you add this!?". While I appreciate all the great and free work that several great individuals do for the community. I personally don't see the need to alter any of these TEGRA/Board drivers a whole lot - not on these latest generation of devices. Things run pretty well I think.

"Why don't you just run the stock kernel then you sick low-life waste of space?"

Because, I still think improvements can be made.

I think there's a lot of good intentions out there to make improvements in the kernel-space, BUT:

I've observed a variety of things that were prevalent a couple of years ago and that are still prevalent today. (1) A lot of small things are changed - and advertised as a huge improvement, (2) some tunables are adjusted and advertised as a huge change/improvement but end up being a regression because they were never tested, or (3) some code is merged that causes regressions and it turns out that self-inflicted bugs are being chased around.

Zen is an attempt at improving the stock kernel. That's it.

Project Summary

The Zen kernel has always been oriented at improving the experience for desktop mobile users as much as possible. This iteration of the series is no different. The goal is simple: Improve the experience.

BFS CPU Scheduler

BFS is an alternative CPU scheduler to the stock kernel's CFS. BFS features a simple single-runqueue O(n) earliest virtual deadline first design. There is no need for excessive balancing to achieve fariness on multiple runqueues, nor is there a need for strict NICE values.

Anyway, not going to get into it much but you may find more information in post 2, or throughout this thread (I explained a bit more details about it around page 4).

Also, check these out:

BFS FAQ

BFS Wikia

Android/Tegra 3.10 BFS Port

What is different about this and the 3.10-ck1 bfs v440 patch available on ck.kolivas.org

Backport fixes and features (not SMT NICE) from up to bfs v460ish

Some of Alfred Chen's upstream synchronization and refactoring of BFS methods (linux-3.18/19-gc branch)

My own syncing with mainline as well as backporting

support for tegra yield notifiers

What does this mean

Suspend/Wake issues that were killer on bfs v440 for 3.10 are not present in this port - these issues have been resolved.

You should NEVER report any issue related to this kernel upstream. Not android, linux, or BFS related. Do not report any issues anywhere but here.

"How about the performance?"

This kernel is all about interactivity by default.

The default rr_interval is set to 6. The logic is the human eye cannot detect jitter until about 7ms. Try lowering it if you want to increase interactivity. Try increasing it to achieve higher thoroughput.

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Zen/Shamu Features

BFS CPU Scheduler

@flar2 Wake Gestures

USB Fastcharge Support

Fsync SysFS Interface

Overclocking support to 2.5GHz

FIOPS + BFQ in addition to the stock ROW, CFQ, Deadline, No-op I/O schedulers

Several misc upstream updates/fixes.

zRam support

@osm0sis AnyKernel2

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Releases

Wipe /cache before flashing for best results

DIRTY FLASH ROM FIRST!

If you have any issues or if you are coming from another custom kernel.

DIRTY FLASH ROM FIRST IF COMING FROM ANOTHER CUSTOM KERNEL

3.10-zen1 "Dollar Drink Night"

First Release/Features:

BFS CPU Scheduler by Con Kolivas. Backport from v461 and Alfred Chen's -gc branch ported to android/tegra 3.10 by me

BFQ + FIOPS I/O Schedulers in addition to CFQ (default), ROW, Deadline

Interactive governor sync'd up with ZenKernel_Shamu

EXT4 from v3.10.y

Several misc. memory leak, race condition fixes, etc. picked from v3.10.y

CPU overclocking up to 2.5GHz

Wake gestures from @flar2

MM+VM Changes from upstream v3.10.y

2A Charging Support

Fsync toggle support

3.10-zen1 AnyKernel Zip (Use for any ROM)

Legacy Releases

3.10-zen0 "Warranty Voided"

Changes:

This is just experimental

Make sure it works

Changes

3.10-zen0 AnyKernel Zip (Use for any ROM)

Thanks guys, and enjoy. Feedback is always appreciated.

XDA:DevDB Information

Zen Kernel, Kernel for the Nexus 9

Contributors

bbedward

Source Code: https://github.com/bbedward/ZenKernel_Flounder

Kernel Special Features:

Version Information

Status: Beta

Current Stable Version: 1

Beta Release Date: 2015-04-19

Created 2015-04-19

Last Updated 2015-04-19