Pushbullet: https://www.pushbullet.com/channel?tag=zen
But you say I'm just a friend
Project Background
First of all. I like the nexus 6. Actually, I really really like the nexus 6. I think the device from factory performs quite marvelously, especially since the 5.1 update. Because of this, I am actually pretty content with running the stock kernel. "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 MSM/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 fordesktop 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
earliest virtual deadline first design. There is no need for excessive balancing to achieve fariness on multiple runqueues - fairness is ensured by deadlines.
BFS is tweaked towards human perception. It is not a real-time scheduler (like the SCHED_DEADLINE policy/scheduling in 3.14+) nor does it use runtimes+red/black trees to figure out fairness. It uses deadlines with the 6ms rr_interval based on the fact that humans cannot detect jitters until >= 7ms.
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/MSM 3.10 BFS Port
What is different about this and the 3.10-ck1 bfs v440 patch available on ck.kolivas.org
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.
-------------------------
Zen/Shamu Features
I work based on real results from user experience, not numbers. I don't claim anything as a big deal if it isn't one. Zen is a no-nonsense, well-tested kernel making real improvements to interactivity in the kernel space.
---------
Releases
All of these builds are for android 5.1 and above, unless otherwise noted
Wipe /cache before flashing for best results
Versions
- Recovery Zip: Kernel+Ramdisk: Use this on a stock/stock-like rom, or on a rom without support for things like viper4android or init.d support. Flash in recovery.
- Boot.IMG: Kernel+Ramdisk: Same as recovery zip, except in the raw boot.img form. Can be flashed in fastboot, flashify, etc.
- ZenyKernel Zip: Kernel Only (+ no force encryption +f2fs support +zen settings): Will use the exact same ramdisk you already have. If you have issues with the other full versions, then dirty flash your rom and this on top of it.
3.10-zen21 "Cheap and Easy"
Changes:
3.10-zen21 Recovery Zip Download
3.10-zen21 boot.img (install via fastboot/twrp IMG) Download
3.10-zen21 ZenyKernel Zip (Use on top of ROM dirty flash if issues with the above two)
Legacy Releases
ZenDecision (zen20+)
You can still turn on MPDecision without any ill effects if desired
As of 5.1+ MPDecision is somehow responsible for at least the following:
ZenDecision is a simple "handler" for to keep CPUs online by the following logic:
ZenDecision tunables (/sys/kernel/zen_decision/):
How to enable overclocking (zen6+)
If your device is unstable at the overclocked frequencies, it is a hardware limitation with your device. Do not report it as a bug
To enable overclocking on zen6 or newer, you will need to use the recovery zip/aroma below.
You choose the max frequency you want, it pulls the boot.img from the device, adds a boot parameter specifying the OC frequency.
If you are not on zen6 or newer it will have no affect.
This does not install a kernel, you still have to install the kernel from one of the links above
Zen Overclock Enable v2
3.09GHz step only supported on zen20+
Thanks guys, and enjoy. Feedback is always appreciated.
XDA:DevDB Information
Zen Kernel, Kernel for the Nexus 6
Contributors
bbedward, purian23
Source Code: https://github.com/bbedward/ZenKernel_Shamu/
Kernel Special Features: Android/MSM BFS Port, kcal, gestures, cool stuff
Version Information
Status: Stable
Current Stable Version: 21
Stable Release Date: 2015-05-20
Created 2015-03-24
Last Updated 2015-05-20
But you say I'm just a friend
Project Background
First of all. I like the nexus 6. Actually, I really really like the nexus 6. I think the device from factory performs quite marvelously, especially since the 5.1 update. Because of this, I am actually pretty content with running the stock kernel. "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 MSM/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
BFS CPU Scheduler
BFS is an alternative CPU scheduler to the stock kernel's CFS. BFS features a simple single-runqueue O
earliest virtual deadline first design. There is no need for excessive balancing to achieve fariness on multiple runqueues - fairness is ensured by deadlines.BFS is tweaked towards human perception. It is not a real-time scheduler (like the SCHED_DEADLINE policy/scheduling in 3.14+) nor does it use runtimes+red/black trees to figure out fairness. It uses deadlines with the 6ms rr_interval based on the fact that humans cannot detect jitters until >= 7ms.
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/MSM 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
- 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.
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.
-------------------------
Zen/Shamu Features
- BFS CPU Scheduler
- @flar2 Wake Gestures
- @savoca KCAL Screen Color Control
- @imoseyon Vibration SysFS interface
- USB Fastcharge Support
- Fsync SysFS Interface
- Overclocking support
- Flar2 userspace CPU voltage control
- f2fs support and latest f2fs: f2fs/dev (even with ZenyKernel zip)
- FIOPS + BFQ + SIO in addition to the stock ROW, CFQ, Deadline, No-op I/O schedulers
- Several misc. CAF/msm + upstream updates/fixes.
- Forced encryption disabled. (Even With ZenyKernel zip)
- Added init.d support (ZenyKernel is up to your existing ROM/kernel)
- selinux adjustments for viper4android and other things (ZenyKernel is up to your existing ROM/kernel)
- Compatible with most ROMs, use ZenyKernel zip if there's compatibility issues.
- Added zRam support
- MPDecision disabled by default, replaced by touchboost listener + ZenDecision 2.0
- ZenyKernel based on @osm0sis AnyKernel2 to use for roms who break compatibility with stock ramdisk
I work based on real results from user experience, not numbers. I don't claim anything as a big deal if it isn't one. Zen is a no-nonsense, well-tested kernel making real improvements to interactivity in the kernel space.
---------
Releases
All of these builds are for android 5.1 and above, unless otherwise noted
Wipe /cache before flashing for best results
Versions
- Recovery Zip: Kernel+Ramdisk: Use this on a stock/stock-like rom, or on a rom without support for things like viper4android or init.d support. Flash in recovery.
- Boot.IMG: Kernel+Ramdisk: Same as recovery zip, except in the raw boot.img form. Can be flashed in fastboot, flashify, etc.
- ZenyKernel Zip: Kernel Only (+ no force encryption +f2fs support +zen settings): Will use the exact same ramdisk you already have. If you have issues with the other full versions, then dirty flash your rom and this on top of it.
3.10-zen21 "Cheap and Easy"
Changes:
- Compile with GCC 5.1
- Several bcmdhd/wifi driver updates
- Misc. CAF updates
- Fix come cores sticking to performance governor
3.10-zen21 Recovery Zip Download
3.10-zen21 boot.img (install via fastboot/twrp IMG) Download
3.10-zen21 ZenyKernel Zip (Use on top of ROM dirty flash if issues with the above two)
Legacy Releases
ZenDecision (zen20+)
You can still turn on MPDecision without any ill effects if desired
As of 5.1+ MPDecision is somehow responsible for at least the following:
- Raise MIN_FREQ to 1497MHz for 3 seconds on touch events
- Ensure CPUs come online after certain events, like thermal events (due to low battery for example)
ZenDecision is a simple "handler" for to keep CPUs online by the following logic:
- When screen comes on, make sure all CPUs are online if current battery level is above bat_threshold_ignore
ZenDecision tunables (/sys/kernel/zen_decision/):
- enabled (0=disabled, 1=enabled): Enable/Disable the driver from doing any work
- wake_wait_time (0-60000 ms, 1000 by default): How long to wait to execute CPU_UP work after screen comes online.
- bat_threshold_ignore(1-100, 0=disabled, 15 by default): The battery percentage to ignore CPU_UP operations. If current battery level is below this level, then the driver is essentially disabled.
How to enable overclocking (zen6+)
If your device is unstable at the overclocked frequencies, it is a hardware limitation with your device. Do not report it as a bug
To enable overclocking on zen6 or newer, you will need to use the recovery zip/aroma below.
You choose the max frequency you want, it pulls the boot.img from the device, adds a boot parameter specifying the OC frequency.
If you are not on zen6 or newer it will have no affect.
This does not install a kernel, you still have to install the kernel from one of the links above
Zen Overclock Enable v2
3.09GHz step only supported on zen20+
Thanks guys, and enjoy. Feedback is always appreciated.
XDA:DevDB Information
Zen Kernel, Kernel for the Nexus 6
Contributors
bbedward, purian23
Source Code: https://github.com/bbedward/ZenKernel_Shamu/
Kernel Special Features: Android/MSM BFS Port, kcal, gestures, cool stuff
Version Information
Status: Stable
Current Stable Version: 21
Stable Release Date: 2015-05-20
Created 2015-03-24
Last Updated 2015-05-20
Last edited:
