[KERNEL][EAS][EOL][9/10/TREBLE][G95xF/FD/N] RZ Kernel for Samsung Galaxy S8(+) - Samsung Galaxy S8 & S8+ Cross Device Development

Code:
#include
/*
* Your warranty is now void.
*
* I am not responsible for bricked devices, dead SD cards,
* thermonuclear war, or you getting fired because the alarm app failed. Please
* do some research if you have any concerns about features included in this kernel
* before flashing it! YOU are choosing to make these modifications, and if
* you point the finger at me for messing up your device, I will laugh at you.*/
RZ Kernel aims for as stock experience as possible. It is made from Samsung's stock kernel with stability updates thanks to great guys who made ELS (exynos-linux-stable) branch
It also attempts to increase overall multitasking performance while maintaining good battery life with proper settings
Features
I/O Scheduler: CFQ (default), noop
Governors
schedutil (DEFAULT FOR EAS)
CPU
Support EAS (Energy Aware Scheduling), which balances battery life while maintaining great overall performance
Fine-tuned schedtune values for super fluid user experience
GPU
Fixed interactive governor for better load burst handling
Memory
Support zRAM with default size of 3/4 RAM size
Multiple compression algorithms for zRAM: zstd, lzo, lz4(default), lz4hc
Other tweaks and optimizations
F2FS filesystem support (require latest TWRP)
Init.d support (A BIG MUST for scripters)
Disabled battery-hogging WAKELOCKS
Westwood TCP congestion algorithm (small boost on network speed)
SELinux Permissive (for V4A and etc...)
WireGuard and DriveDroid support
XDA:DevDB Information
RZ Kernel, Kernel for the Samsung Galaxy S8
Contributors
remilia15
Source Code: https://github.com/diepquynh/android_kernel_samsung_universal8895
Kernel Special Features: Energy Aware Scheduling
Version Information
Status: Testing
Created 2019-01-24
Last Updated 2020-08-27

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Download link: Drive folder
CHANGELOG:
20190124 (OREO): Initial release
20190129 (OREO): Post #36
20190201 (OREO): Post #39
20190203 (OREO): Post #47
20190210 (OREO): Post #60
20190213 (OREO): Post #70
20190218 (OREO): Post #81
20190223 (PIE): Post #88
20190225 (PIE): Post #110
20190227 (PIE): Post #125
20190310 (PIE): Post #128
20190321 (PIE): Post #148
20190329 (PIE): Post #158
20190430 (PIE): Post #172
20190503 (PIE): Post #176
20190828 (PIE): Post #220
20190909 (PIE): Post #245
20191014 (PIE): Post #290
20200406 (PIE): Post #307
20200822 (PIE) [FINAL]: Post #339

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Notices and Q&A
The kernel is based on tw90-android branch of ELS, which is currently at stable state from my experience
Other related features of the kernel were picked from other sources. Credits belong to the owner
I have totally ditched Samsung's HMP implementation by myself, and adapted aosp-common kernel's EAS commits with the brand new kernel scheduler (called Exynos Mobile Scheduler (EMS)) from Exynos 9820 kernel source, which seemed doing nice on our Exynos 8895. Because HMP isn't doing really well on our 8895, and to take advantage of 64bit kernel, I've done EAS by myself
The kernel's EAS figures were self-made using specific CPU capacity benchmarks and energy usage measurements, along with performance benchmarks for better balance and improved as possible
Questions and Answers (Q&A)
Q: My phone gets hot while using this kernel?
A: Short answer: It's your own issue, fix it yourself. Nobody makes a kernel just to burn your hands
Long answer:
Install Termux app from Play Store
Enable screen rotation, open Termux in landspace mode
Type this command: su -c top -d 2
A list of processes will appear and refresh with 2s interval. Find which process consumes the most CPU usage with [%CPU] column and the package name in ARGS column. You should see the culprit of your issue
Reminder: There is no such thing as "I have nothing in background but the phone still heats up". There definitely something happen and 99% of the time it's some of the rogue apps running in background
Q: Can you add X Y Z feature to this kernel?
A: I want to keep the kernel clean and simple. However, if the feature is really useful, I'll consider adapting it with proper performance check before releasing
Q: I can't connect to any access point after installing this kernel?
A: If you can't connect to an access point on stock/stock-based ROM, simply forget its password and connect again
Q: This kernel is unbootable on my One UI ROM?
A: If you came from previous builds, it's because of Secure Folder. You can either continue using previous build (which I would not recommend) or uninstall Secure Folder, install the latest build and reinstall it again. It's all because I have removed Samsung's FIPS cryptographic API which breaks device encryption
Q: My touchscreen/XYZ hardware stuff doesn't work after flashing kernel
A: Make sure your flashing procedure is right. I'd recommend flashing the kernel with a clean stock boot.img (Magisk or SuperSU-patched one is also okay)
Also, check your device name first before downloading (S8/S8+ and it has to be EXYNOS)

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Installation instructions
Select proper kernel variant to download (Stock SE/One UI, LineageOS, Treble)
Put the downloaded kernel flashable zip in the internal storage or SD card
Flash the zip with ease (no root re-installation needed, because the kernel isn't shipped with prebuilt stock boot.img)
Selecting kernel variant:
Non-treble ROMs: RZ-LineageOS-* (might not compatible with all non-treble ROMs as each might use its own kernel and stuffs)
Treble ROMs: RZ-treble (note that it is meant to be used with hadesTreble). If you didn't install hadesTreble, use non-treble build for non-treble AOSP ROMs
One UI/Stock SE: The remaining build

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Reserved

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Thanks will try 6 hrs sot is great

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Thank you for this great kernel!
Στάλθηκε από το SM-G955F μου χρησιμοποιώντας Tapatalk

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Is this kernel compatible for Android Pie ?

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The more the merrier. Happy to see some more development. Was also curious about EAS feature, velocity had the governer (schedutil) but it freezes like hell.

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parser said:
The more the merrier. Happy to see some more development. Was also curious about EAS feature, velocity had the governer (schedutil) but it freezes like hell.
Click to expand...
Click to collapse
For now none of the custom kernels has EAS by default. Samsung used HMP for our 8895 and recently implemented EAS for 9810
For more information about EAS, read here:
https://elinux.org/images/6/69/Eas-unbiased1.pdf
https://developer.arm.com/open-source/energy-aware-scheduling
schedutil is a governor born for EAS. It bases on the energy costs table to decide which frequency should be chosen under specified workload
This is different from load-based capacity calculations of HMP with interactive governor. It needs almost zero userspace interact. Installing a kernel with EAS is just "Flash and forget". Governor tweaks are unavailable for schedutil because the CPU up/down rates depends on CPU's transition latency, which is independent among all SoCs

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EAS on the S8? Superb work here, mate. Makes me regret selling my S8+ even more now
---------- Post added at 10:13 AM ---------- Previous post was at 10:07 AM ----------
@remilia15 a question regarding the schedtune boost configuration: are you setting the same values for all cgroups (i.e. foreground, top-app etc.) or are these specific per cgroup? Also, when enabling schedtune via the Spectrum profiles, are you also enabling the prefer_idle value?

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Maverick Jester said:
EAS on the S8? Superb work here, mate. Makes me regret selling my S8+ even more now
---------- Post added at 10:13 AM ---------- Previous post was at 10:07 AM ----------
@remilia15 a question regarding the schedtune boost configuration: are you setting the same values for all cgroups (i.e. foreground, top-app etc.) or are these specific per cgroup? Also, when enabling schedtune via the Spectrum profiles, are you also enabling the prefer_idle value?
Click to expand...
Click to collapse
I use 10 and 0 for top-app and foreground with Performance mode, as well as 50 and 60 for Gaming mode
prefer_idle is always 1 for all modes
But I'm still investigating about Exynos thermal driver, because it is too agressive regarding frequencies handling
Sent from my SM-G955F using XDA Labs

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gregou said:
Is this kernel compatible for Android Pie ?
Click to expand...
Click to collapse
Unfortunately no. There haven't been any P kernel sources yet for 8895
Sent from my SM-G955F using XDA Labs

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remilia15 said:
For now none of the custom kernels has EAS by default. Samsung used HMP for our 8895 and recently implemented EAS for 9810
For more information about EAS, read here:
https://elinux.org/images/6/69/Eas-unbiased1.pdf
https://developer.arm.com/open-source/energy-aware-scheduling
schedutil is a governor born for EAS. It bases on the energy costs table to decide which frequency should be chosen under specified workload
This is different from load-based capacity calculations of HMP with interactive governor. It needs almost zero userspace interact. Installing a kernel with EAS is just "Flash and forget". Governor tweaks are unavailable for schedutil because the CPU up/down rates depends on CPU's transition latency, which is independent among all SoCs
Click to expand...
Click to collapse
I had checked EAS when I first saw schedutil in the kernel I mentioned. Its good to see it implemented into our phone.
Installed the kernel and trying out now.
Alittle request if you don't mind. Wakelock blocker would be nice addon. And if its not much flickerfree.
Thanks for you great work mate!

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remilia15 said:
I use 10 and 0 for top-app and foreground with Performance mode, as well as 50 and 60 for Gaming mode
prefer_idle is always 1 for all modes
But I'm still investigating about Exynos thermal driver, because it is too agressive regarding frequencies handling
Sent from my SM-G955F using XDA Labs
Click to expand...
Click to collapse
Appreciate the feedback. Thanks.
I agree with the other poster that the Boeffla wakelock blocker along with the PWM flickerfree module being incorporated into your kernel would be fantastic additions.

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I would like to talk to you personally on telegram, please contact me at @ Vaughnell . Thanks

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Hello, thanks for this kernel, i have real all posts on this thread but I can't find how do I change the Setting Spectrum profiles?

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BAYmustafa96 said:
Hello, thanks for this kernel, i have real all posts on this thread but I can't find how do I change the Setting Spectrum profiles?
Click to expand...
Click to collapse
Use Spectrum app. It's free
Sent from my SM-G955F using XDA Labs

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parser said:
I had checked EAS when I first saw schedutil in the kernel I mentioned. Its good to see it implemented into our phone.
Installed the kernel and trying out now.
Alittle request if you don't mind. Wakelock blocker would be nice addon. And if its not much flickerfree.
Thanks for you great work mate!
Click to expand...
Click to collapse
Maverick Jester said:
Appreciate the feedback. Thanks.
I agree with the other poster that the Boeffla wakelock blocker along with the PWM flickerfree module being incorporated into your kernel would be fantastic additions.
Click to expand...
Click to collapse
Both of these I have done several tests
For wakelock blocker, I couldn't find any actual battery differences. There weren't any drivers that trigger actual CPU wakelocks so I don't adapt it in the kernel
About flickerfree, it's pretty nice, but I'll still need to investigate more before adding this feature permanently because we all don't want weird burn-in in our AMOLED screen. Moreover, I think there will be another disadvantage of it, which is battery impact
Edit: I actually need to investigate more about wakelocks of this device
Sent from my SM-G955F using XDA Labs

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@remilia15 your kernel has no way of rooting it with super su or magisk and ur kernel doesn't come pre-installed with a rooting method so am asking myself what is the real purpose of this kernel that i cannot root? ?*