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Development [r1] arter97 kernel for OnePlus 9 series

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arter97

Recognized Developer
Oct 14, 2012
3,780
33,913
23
Seoul
arter97-xda.png



arter97 kernel for OnePlus 9 series running OxygenOS

/* Features */

Supports OnePlus 9 series
Fully rebased kernel without unnecessary OnePlus code
Latest CAF msm-5.4 kernel fully merged
Latest Linux v5.4 subversion merged
Latest Google’s security fix merged
BBR as the default TCP network congestion control
Features the latest WireGuard
Modules support disabled for lighter kernel
Latest Wi-Fi drivers from Qualcomm with customized config
Built with Clang 12 and ThinLTO
Power optimizations
Memory management optimizations
Latest SELinux subsystem backported from mainline
Latest f2fs backported from mainline
Latest BFQ I/O scheduler backported from mainline
mmap/mremap backported from mainline for a major performance boost
Touchscreen optimizations for lower latency
Uses LRNG for better performance

/* Details */

- Fully rebased kernel without unnecessary OnePlus code -



This kernel is not based on the stock OxygenOS kernel source provided by OnePlus. Instead, it’s based on the latest and greatest Qualcomm has to offer. Only the necessary parts from the OnePlus kernel have been cherry-picked, such as OnePlus 9 specific device drivers.

This effectively kills all kernel modifications/optimizations from OnePlus, including the infamous app throttler.
Due to the completely different base, this kernel will behave drastically different from other kernels, in both good and bad ways.


- Power optimizations -


This kernel makes some conscious decisions for reducing power consumption.

First, the stock OnePlus configuration forces display-related processes to use the big cores exclusively.
This configuration brings a huge power regression since it makes every frame dispatch to wake up and use the power-hungry cores.

This kernel resets this profile to use the configuration Google recommends, which is to use the LITTLE cores exclusively instead.

Second, this kernel disables wakelocks upon Wi-Fi’s RX unicast packet transmissions. qcom_rx_wakelock is one of the major culprits to increased idle power consumption. Although its total wakelock time is quite low, it's catched very frequently and prevents the system from entering suspend repeatedly.

As dropping unicast or local ARP packets doesn’t pose practical issues on Android, this kernel disables qcom_rx_wakelock.

Third, this kernel reduces the duration of the Bluetooth ISR wakelock from 2 seconds to 100ms. This was done from an observation that the average userspace response time from ISR is less than 10ms.
My kernels have been doing this for years and no Bluetooth-related issues were reported.

Fourth, the vibrator driver used in this kernel no longer controls the cpuidle driver. The stock kernel disables the cpuidle whenever the vibrator is used. This kernel disables it as the vibrator is not that sensitive to deadline misses.

There are other small improvements throughout the kernel tree as well.


- Memory management optimizations -


This kernel disables LMKD and uses an in-kernel solution called SimpleLMK, made by kerneltoast. You can track how often SimpleLMK kicks in by monitoring:
Code:
/sys/module/lowmemorykiller/parameters/lmk_count

This kernel also changes a lot related to swap and zram.

The swap-related code has been backported from Linux v5.9 (link1, link2) to efficiently support fast swap device and allow swappiness over 100. This kernel currently sets swappiness to 160 on < 6GB of RAM, 120 on 8GB and 90 on 12GB.

zram has been also backported from mainline Linux and further tweaked to use block device writeback. This is equivalent to the recent “RAM Plus” feature that companies have been marketing that uses the internal storage to extend RAM.

This kernel uses zram writeback to offload idle pages (i.e., really, really unused RAM) to the internal storage. As it's extremely slow to bring pages back from UFS, writeback code works quite conservatively. It'll start to writeback pages that haven't been used for a day or two. It makes use of the hidden 2GB “last_parti” partition from the UFS storage.

Along with zram writeback, this kernel also enables deduplication with xxHash. Each page stored in zram is checked for deduplication to further save memory. With these 2 features combined, RAM reaching 1GB is additionally saved, but your mileage may vary.

The post boot script used in the stock ROM is also overridden and it sets the readahead to 128KB. As I/O workload under Android is mostly random, high readahead doesn’t help and only increases memory thrashing.

This kernel also incorporates a lot of patches to reduce/optimize memory allocations used throughout the entire kernel.

mmap/mremap code was also backported from Linux v5.10 to optimize ART (see here for more info).


- Latest subsystems -


This kernel backports the SELinux subsystem from mainline Linux. This includes caching improvements that drastically reduces time spent on lookups. 10K lines of code has been changed.

This kernel also backports f2fs (Flash-Friendly File System) from mainline Linux. This includes bug fixes and performance improvements such as shorter discard latency, more optimized GC logic for Android, and checkpoint merging.

BFQ I/O scheduler has also been backported from mainline Linux for better I/O performance.


- LRNG -


This kernel ditches the traditional RNG driver from the Linux kernel in favor of LRNG. See here and here for more info.

A rudimentary throughput benchmark shows an improvement of 10.5% (keep in mind that this is only one aspect of an RNG metric).


/* Notice */

Only OxygenOS on Android 11 is supported.

This kernel touches vendor_boot and dtbo partitions, meaning you'd need to restore said partitions whenever you're switching to another kernel or stock.
Please make a back-up of these partitions. The installer doesn’t do this automatically for you. Installing the stock ROM with a full OTA restores said partitions as well.

/* Disclaimer */

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. Hard. A lot.

/* Thanks to */

Vishalcj17
kristofpetho
kdrag0n
kerneltoast (SultanXDA)

/* Instructions */

1. Read the above. Please.
2. Flash the zip file from FK Kernel Manager. Any other installation methods are untested.

/* Downloads and links */

arter97.com
Kernel source
Telegram chat link
 
Last edited:

rejectedjs

Senior Member
Apr 1, 2012
381
120
Holy **** this is exciting. This kernel is the one that I ran back on my OP7P and it's why I loved that phone so much. Is the 9 why you stopped development on that device?
 
  • Like
Reactions: galaxys

basboosa

New member
Mar 16, 2018
2
3
Does vendor _boot get altered after flashing kernel meaning flash back untouched backed up vendor boot to take next ota?

Was using this kernel briefly, and just updated to 11.2.9.9 (Global), had to flash stock vendor_boot, dtbo, and boot to be able to upgrade.


Anyone running this yet? If so how is it? Thinking of flashing this on stock 11.2.9.9

During my brief time using the kernel, had a minor issue whereby AUX (via USB-C) in my car wasn't working.


BTW thanks for the awesome kernel, planning to use it once wireguard support is added!
 

arter97

Recognized Developer
Oct 14, 2012
3,780
33,913
23
Seoul
Another new alpha build is up with big changes yet again.
I still have quite a few TODOs left, but I ported many changes from my OnePlus 7 Pro kernel.

Wi-Fi will behave differently with this kernel, so please let me know if you encounter Wi-Fi issues.

r1a7

Wi-Fi configuration merged with the latest CAF
Wi-Fi's rx_wakelock disabled and removed
Support for WireGuard added
Bunch of memory optimizations
Bunch of optimizations for screen and the GPU driver
 
Last edited:

Top Liked Posts

  • There are no posts matching your filters.
  • 15
    After using the kernel myself and daily driving for few days and monitoring how the kernel behaves, I now feel comfortable to mark it stable.

    r1 is released.

    The original post is re-written to feature what's special with this kernel.
    Please take your time and re-read the original post.
    8
    r1a13 is up for minor bug fix.
    Previous builds may have silently corrupted memory due to zram. All users are advised to upgrade to r1a13.

    r1a13
    Hashing algorithm switched from crc32c to xxh64 from zram to reduce collision
    8
    Another alpha build with a lot of changes, r1a12 is up.

    Now, my kernel's TODO list is done and I hope this kernel is stable enough so that I can move on from the "alpha" tag.
    I'm still marking it an alpha as a lot changed.

    I've re-uploaded r1a12 as r1a11 was durped.

    r1a12
    Linux v5.4.150 merged
    Touchscreen optimizations
    Disabled debugging/unnecessary configs to optimize performance
    Backported SELinux from mainline Linux for better performance
    Backported BFQ scheduler from mainline Linux for better performance
    Backported mremap optimizations (see here for more info)
    Fixed more issues related to Type-C audio dongles (thanks to @Freak07)
    Backported some meaningful swap memory management commits from mainline
    Switched to LRNG for better RNG performance (see here for more info)
    Fixed zram writeback not working properly with previous builds
    Ported device-specific memory optimizations from my previous OnePlus 7 kernel
    Enabled ThinLTO for better compiler optimizations
    4
    Hola, ¿dónde podemos descargar este deshabilitador TPD?
    Hello.flash via magisk
    3
    Used Omega for months and just flashed this kernel. Instantly I notice an improvement in scrolling smoothness. So far, everything seem to work properly. I'm on 12.8.8.8
  • 38
    arter97-xda.png



    arter97 kernel for OnePlus 9 series running OxygenOS

    /* Features */

    Supports OnePlus 9 series
    Fully rebased kernel without unnecessary OnePlus code
    Latest CAF msm-5.4 kernel fully merged
    Latest Linux v5.4 subversion merged
    Latest Google’s security fix merged
    BBR as the default TCP network congestion control
    Features the latest WireGuard
    Modules support disabled for lighter kernel
    Latest Wi-Fi drivers from Qualcomm with customized config
    Built with Clang 12 and ThinLTO
    Power optimizations
    Memory management optimizations
    Latest SELinux subsystem backported from mainline
    Latest f2fs backported from mainline
    Latest BFQ I/O scheduler backported from mainline
    mmap/mremap backported from mainline for a major performance boost
    Touchscreen optimizations for lower latency
    Uses LRNG for better performance

    /* Details */

    - Fully rebased kernel without unnecessary OnePlus code -



    This kernel is not based on the stock OxygenOS kernel source provided by OnePlus. Instead, it’s based on the latest and greatest Qualcomm has to offer. Only the necessary parts from the OnePlus kernel have been cherry-picked, such as OnePlus 9 specific device drivers.

    This effectively kills all kernel modifications/optimizations from OnePlus, including the infamous app throttler.
    Due to the completely different base, this kernel will behave drastically different from other kernels, in both good and bad ways.


    - Power optimizations -


    This kernel makes some conscious decisions for reducing power consumption.

    First, the stock OnePlus configuration forces display-related processes to use the big cores exclusively.
    This configuration brings a huge power regression since it makes every frame dispatch to wake up and use the power-hungry cores.

    This kernel resets this profile to use the configuration Google recommends, which is to use the LITTLE cores exclusively instead.

    Second, this kernel disables wakelocks upon Wi-Fi’s RX unicast packet transmissions. qcom_rx_wakelock is one of the major culprits to increased idle power consumption. Although its total wakelock time is quite low, it's catched very frequently and prevents the system from entering suspend repeatedly.

    As dropping unicast or local ARP packets doesn’t pose practical issues on Android, this kernel disables qcom_rx_wakelock.

    Third, this kernel reduces the duration of the Bluetooth ISR wakelock from 2 seconds to 100ms. This was done from an observation that the average userspace response time from ISR is less than 10ms.
    My kernels have been doing this for years and no Bluetooth-related issues were reported.

    Fourth, the vibrator driver used in this kernel no longer controls the cpuidle driver. The stock kernel disables the cpuidle whenever the vibrator is used. This kernel disables it as the vibrator is not that sensitive to deadline misses.

    There are other small improvements throughout the kernel tree as well.


    - Memory management optimizations -


    This kernel disables LMKD and uses an in-kernel solution called SimpleLMK, made by kerneltoast. You can track how often SimpleLMK kicks in by monitoring:
    Code:
    /sys/module/lowmemorykiller/parameters/lmk_count

    This kernel also changes a lot related to swap and zram.

    The swap-related code has been backported from Linux v5.9 (link1, link2) to efficiently support fast swap device and allow swappiness over 100. This kernel currently sets swappiness to 160 on < 6GB of RAM, 120 on 8GB and 90 on 12GB.

    zram has been also backported from mainline Linux and further tweaked to use block device writeback. This is equivalent to the recent “RAM Plus” feature that companies have been marketing that uses the internal storage to extend RAM.

    This kernel uses zram writeback to offload idle pages (i.e., really, really unused RAM) to the internal storage. As it's extremely slow to bring pages back from UFS, writeback code works quite conservatively. It'll start to writeback pages that haven't been used for a day or two. It makes use of the hidden 2GB “last_parti” partition from the UFS storage.

    Along with zram writeback, this kernel also enables deduplication with xxHash. Each page stored in zram is checked for deduplication to further save memory. With these 2 features combined, RAM reaching 1GB is additionally saved, but your mileage may vary.

    The post boot script used in the stock ROM is also overridden and it sets the readahead to 128KB. As I/O workload under Android is mostly random, high readahead doesn’t help and only increases memory thrashing.

    This kernel also incorporates a lot of patches to reduce/optimize memory allocations used throughout the entire kernel.

    mmap/mremap code was also backported from Linux v5.10 to optimize ART (see here for more info).


    - Latest subsystems -


    This kernel backports the SELinux subsystem from mainline Linux. This includes caching improvements that drastically reduces time spent on lookups. 10K lines of code has been changed.

    This kernel also backports f2fs (Flash-Friendly File System) from mainline Linux. This includes bug fixes and performance improvements such as shorter discard latency, more optimized GC logic for Android, and checkpoint merging.

    BFQ I/O scheduler has also been backported from mainline Linux for better I/O performance.


    - LRNG -


    This kernel ditches the traditional RNG driver from the Linux kernel in favor of LRNG. See here and here for more info.

    A rudimentary throughput benchmark shows an improvement of 10.5% (keep in mind that this is only one aspect of an RNG metric).


    /* Notice */

    Only OxygenOS on Android 11 is supported.

    This kernel touches vendor_boot and dtbo partitions, meaning you'd need to restore said partitions whenever you're switching to another kernel or stock.
    Please make a back-up of these partitions. The installer doesn’t do this automatically for you. Installing the stock ROM with a full OTA restores said partitions as well.

    /* Disclaimer */

    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. Hard. A lot.

    /* Thanks to */

    Vishalcj17
    kristofpetho
    kdrag0n
    kerneltoast (SultanXDA)

    /* Instructions */

    1. Read the above. Please.
    2. Flash the zip file from FK Kernel Manager. Any other installation methods are untested.

    /* Downloads and links */

    arter97.com
    Kernel source
    Telegram chat link
    15
    After using the kernel myself and daily driving for few days and monitoring how the kernel behaves, I now feel comfortable to mark it stable.

    r1 is released.

    The original post is re-written to feature what's special with this kernel.
    Please take your time and re-read the original post.
    9
    Another new alpha build is up with big changes yet again.
    I still have quite a few TODOs left, but I ported many changes from my OnePlus 7 Pro kernel.

    Wi-Fi will behave differently with this kernel, so please let me know if you encounter Wi-Fi issues.

    r1a7

    Wi-Fi configuration merged with the latest CAF
    Wi-Fi's rx_wakelock disabled and removed
    Support for WireGuard added
    Bunch of memory optimizations
    Bunch of optimizations for screen and the GPU driver
    9
    r1a10 is up. (r1a9 is skipped as an internal build)

    This build now drastically changes the file-system code, bringing it from v5.4 to v5.15 (mainline Linux) with 13K code line changes.

    While I expect it to be stable, there might be a possibility that it may end up causing incompatibilities with the OnePlus 9's encryption code.

    So please, back up your data before using this build if you haven't already.

    Another notable change is that the USB OTG and Type-C audio jack is also fixed.

    r1a10

    Merged the latest Qualcomm LA.UM.9.14.r1-18300-LAHAINA.0 tag
    Fixed USB OTG and Type-C audio jack
    Merged the mainline f2fs from Linux v5.15
    8
    r1a13 is up for minor bug fix.
    Previous builds may have silently corrupted memory due to zram. All users are advised to upgrade to r1a13.

    r1a13
    Hashing algorithm switched from crc32c to xxh64 from zram to reduce collision