Development [r12] arter97 kernel for OnePlus 9 series

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Warrkill

Member
Nov 2, 2021
34
17
So, if I haven't backed up my partitions, can I just boot into twrp, flash 10.10 and boot into system without any issues? Someone tested?
Backing up and restoring is such pain in ...
Thnx in advance
 

Amd4life

Senior Member
Dec 30, 2010
1,844
438
Google Pixel 6 Pro
So, if I haven't backed up my partitions, can I just boot into twrp, flash 10.10 and boot into system without any issues? Someone tested?
Backing up and restoring is such pain in ...
Thnx in advance

I booted into twrp (not flash), then flashed 10.10 in twrp, rebooted into system (choose the correct slot), and my system booted up fine. If it stalls on boot, choose the other slot. Also make sure you remove your screen lock BEFORE using TWRP.

I re-rooted the new firmware using the pre-patched boot method. Then rebooted. Then used FK Kernel to re-install the kernel. No need to wipe data, thankfully.
 

thirtythr33

Senior Member
Sep 3, 2011
347
151
New York
OnePlus 6T
OnePlus 9 Pro
Yeah, restoring via fastboot is reliable. And it's basically the same steps: Restore, then upgrade locally, then for root you can either patch the kernel or flash Magisk via TWRP.

I only went for the kernel patch option because I was too paranoid to flash TWRP and risk losing my data. Is it safe to flash it without wiping anything?
when you fastboot flashed the img's, did you specify a slot or simply flash without specifying a slot? just wondering
 

Fishawy

Senior Member
Mar 26, 2010
3,208
550
Melbourne
OnePlus 9 Pro
when you fastboot flashed the img's, did you specify a slot or simply flash without specifying a slot? just wondering
I had 2 dtbo and vendor_boot images for each slot, the backup had them named dtbo_a and dtbo_b. So I did fastboot getvar current-slot first to confirm the slot, then just fastboot flash dtbo dtbo_a.img .
 

thirtythr33

Senior Member
Sep 3, 2011
347
151
New York
OnePlus 6T
OnePlus 9 Pro
I had 2 dtbo and vendor_boot images for each slot, the backup had them named dtbo_a and dtbo_b. So I did fastboot getvar current-slot first to confirm the slot, then just fastboot flash dtbo dtbo_a.img .
thanks for the response. yeah I only have a backup of the images from the telegram group, but I can flash each one to both slot a and b, but I was just wondering if it was necessary to get the update to take, bc the basic command 'fastboot flash boot boot.img' or whatever is being flashed will auto flash to the current active slot
 

Fishawy

Senior Member
Mar 26, 2010
3,208
550
Melbourne
OnePlus 9 Pro
thanks for the response. yeah I only have a backup of the images from the telegram group, but I can flash each one to both slot a and b, but I was just wondering if it was necessary to get the update to take, bc the basic command 'fastboot flash boot boot.img' or whatever is being flashed will auto flash to the current active slot
Sorry mate, I don't have a clear answer to that, this whole slots thing is confusing and risky. Hopefully you will get better support on Telegram.
 
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tathagatab

Senior Member
Dec 31, 2014
426
188
Kolkata
OnePlus 9 Pro
thanks for the response. yeah I only have a backup of the images from the telegram group, but I can flash each one to both slot a and b, but I was just wondering if it was necessary to get the update to take, bc the basic command 'fastboot flash boot boot.img' or whatever is being flashed will auto flash to the current active slot
I backed up and restored with dd, and wrote each image to both slots. The update went smoothly.
 

thirtythr33

Senior Member
Sep 3, 2011
347
151
New York
OnePlus 6T
OnePlus 9 Pro
Have you faced any random reboots with r2?
yep, although it took a while to get one (others were getting random reboots sooner than I was) -- in short, when I open my camera, I have about a 1 in 4 chance of getting a reboot, don't know why, but that is the only time I get them. went back to stock bc having my phone reboot when trying to take a video on xmas is something I don't feel like dealing with unfortunately. thing is this kernel is awesome in every way and I wish I could continue using, but that's the deal breaker for me
 
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  • 18
    A major new testing release is up.

    Changes made in this round is big enough that I've decided to name it r20.

    While the build has been stable for me, I'm marking this an alpha as a lot changed.

    r20a1 marks the first Linux v5.4 based kernel to have MGLRU backported.

    MGLRU is a big deal in everything Linux related, especially for Android.
    Esper have a great article on what is MGLRU in a nutshell: https://blog.esper.io/android-dessert-bites-22-linux-memory-management-38419756/

    TL;DR:
    According to Google’s fleetwide profiling, multi-generational LRU yields an “overall 40% decrease in kswapd [the kernel daemon that manages virtual memory] CPU usage,” an “85% decrease in the number of low-memory kills at the 75th percentile,” and an “18% decrease in app launch times at the 50th percentile.”

    Personally, I've noticed a sharp decrease in swap usage and improvements in general performance.

    Besides MGLRU, there are other numerous patches that are worth noting.

    I've brought back updated arm64 routines that were once tried in a beta release but removed later due to random kernel panics (mostly notable from Netflix). The mainline Linux kernel have gotten new updates since then, so r20a1 includes that.
    Also, some memory patches made by Sultan are also picked, and I've confirmed that those also help improving responsiveness.

    With all these memory stuffs going on, I've also changed swap/zram's parameters. You'll notice a difference in how many apps you can keep open, etc.

    The excessive RMNET_DFC wakelock that annoyed some users are now also gone by incorporating a fix from Snapdragon 8 Gen 1.

    All in all, this is indeed a pretty big release.
    I'm expecting mixed feedback, so please let me know how the new kernel behaves.

    /* Full changelog */

    Backported MGLRU
    Fixed full system crash on some custom ROMs (by LibXZR)
    Added a few memory patches to improve responsiveness (by Sultan)
    Tuned swap/zram configurations
    Backported updated arm64 memory functions for better performance
    Fixed excessive RMNET_DFC wakelock
    Fixed OnePlus charging code to handle worker failure
    Backported more BFQ commits from mainline
    Backported mm/mremap fix from mainline
    Latest WireGuard merged
    LA.UM.9.14.r1-19400-LAHAINA.QSSI13.0 merged
    Linux v5.4.190 merged
    Wi-Fi drivers updated to 2.0.8.28K
    2022-04-05 security patch merged
    Latest f2fs from Linux v5.18 merged
    Now built with the latest Clang 14.0.5
    Device-tree updated to LA.UM.9.14.r1-19300-LAHAINA.QSSI13.0
    8
    r20a4 is up.

    Some bug fixes here and there and continued testing for memory management.
    7
    New alpha build r20a2 is up.

    Due to some memory issues causing major lags, I've decided to revert MGLRU for now and take r20 alpha rounds to debug more memory-related issues.
    Simple LMK by Sultan (kerneltoast) is back to speed up memory debugging.

    Please consider joining the Telegram group and sending feedback/logs.

    Thanks.
    4
    r20a5 is up.

    MGLRU is re-enabled with this release.
    Please test how the general performance behaves.
    2
    I don't know what you've done, arter, but I actually have Gmail notifications on r20a5, and I haven't been getting them for months! So thank you. Hopefully they stay!
    this is not kernel related thing, you can reenable gmail notifications on original FW with this commant in terminal
    su -c 'killall zygote'
  • 55
    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 13 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. (Reverted in r2 as it seems like that little cores aren't enough to drive 120 Hz fluidly.)
    This kernel allows these processes to use little and middle cores (0-6), depending on the load.

    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 */

    OxygenOS 12 is unsupported.
    Non-OxygenOS custom ROMs are supported, but your mileage may vary wildly. Most notably, gesture orientations on some ROMs may be inverted.

    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
    18
    A major new testing release is up.

    Changes made in this round is big enough that I've decided to name it r20.

    While the build has been stable for me, I'm marking this an alpha as a lot changed.

    r20a1 marks the first Linux v5.4 based kernel to have MGLRU backported.

    MGLRU is a big deal in everything Linux related, especially for Android.
    Esper have a great article on what is MGLRU in a nutshell: https://blog.esper.io/android-dessert-bites-22-linux-memory-management-38419756/

    TL;DR:
    According to Google’s fleetwide profiling, multi-generational LRU yields an “overall 40% decrease in kswapd [the kernel daemon that manages virtual memory] CPU usage,” an “85% decrease in the number of low-memory kills at the 75th percentile,” and an “18% decrease in app launch times at the 50th percentile.”

    Personally, I've noticed a sharp decrease in swap usage and improvements in general performance.

    Besides MGLRU, there are other numerous patches that are worth noting.

    I've brought back updated arm64 routines that were once tried in a beta release but removed later due to random kernel panics (mostly notable from Netflix). The mainline Linux kernel have gotten new updates since then, so r20a1 includes that.
    Also, some memory patches made by Sultan are also picked, and I've confirmed that those also help improving responsiveness.

    With all these memory stuffs going on, I've also changed swap/zram's parameters. You'll notice a difference in how many apps you can keep open, etc.

    The excessive RMNET_DFC wakelock that annoyed some users are now also gone by incorporating a fix from Snapdragon 8 Gen 1.

    All in all, this is indeed a pretty big release.
    I'm expecting mixed feedback, so please let me know how the new kernel behaves.

    /* Full changelog */

    Backported MGLRU
    Fixed full system crash on some custom ROMs (by LibXZR)
    Added a few memory patches to improve responsiveness (by Sultan)
    Tuned swap/zram configurations
    Backported updated arm64 memory functions for better performance
    Fixed excessive RMNET_DFC wakelock
    Fixed OnePlus charging code to handle worker failure
    Backported more BFQ commits from mainline
    Backported mm/mremap fix from mainline
    Latest WireGuard merged
    LA.UM.9.14.r1-19400-LAHAINA.QSSI13.0 merged
    Linux v5.4.190 merged
    Wi-Fi drivers updated to 2.0.8.28K
    2022-04-05 security patch merged
    Latest f2fs from Linux v5.18 merged
    Now built with the latest Clang 14.0.5
    Device-tree updated to LA.UM.9.14.r1-19300-LAHAINA.QSSI13.0
    18
    r2 is up, and it's a big release.

    Changelog is quite self-explanatory.

    r2
    Display-related processes are now allowed to use the middle cores as well for better smoothness
    Enabled more mremap() performance improvement that was missing from r1
    LA.UM.9.14.r1-18400-LAHAINA.0 merged
    LA.UM.9.16.r1-08100-MANNAR.0 merged
    LA.UM.10.9.1.r1-00300-QCS610.0 merged (contains a lot of new improvements including power optimizations)
    Linux v5.4.159 merged
    Wi-Fi drivers updated to 2.0.8.25M
    2021-11-06 security patch merged
    Watermark boosting disabled to fix aggressive app killings (by Sultan)
    Workaround added to fix unwanted doubles presses from the power button
    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.
    15
    After months of tests, r3 is up and it's a major release that should fixes all major bugs from previous versions and improve performance.


    It turned out that using SimpleLMK causes random soft reboots due to page allocation failures.
    This kernel reverts back to using the stock lmkd until this issue is sorted out.
    You may experience a slight decrease in how many apps you can leave in the background.

    Also, random app crashes and freezes are fixed too.
    This was specific to OxygenOS, which freezes apps with cgroup and expects the kernel to un-freeze them, but with my kernel lacking that feature from OnePlus, using my kernel led to app crashes and freezes.
    This was fixed by forcefully disabling that feature from the kernel.

    Some Bluetooth and USB stuffs were also fixed with this release.


    Bug fixes alone make this a noteworthy release, but it also comes with nice performance improvements.

    With the Qualcomm HDK, I've managed to debug why using Clang 13 leads to boot failures.
    r3 has that issue sorted out and now the kernel uses the latest Clang 13.0.2 instead of 12.

    Read-write semaphore backported from Linux v5.16 will also give some nice latency improvements under heavy I/O.
    These patches are actively being talked in the f2fs mailing list for backporting to older Android devices.

    From Sultan (kerneltoast), r3 also has SLUB per-CPU partial caches disabled for better latency.


    r3
    SimpleLMK disabled for now to fix random soft reboots
    Fixed random app crashes and freezes due to op_cgroup
    Bluetooth drivers re-worked to fix Bluetooth-related issues
    USB malfunctions fixed (dwc3)
    LA.UM.9.14.r1-18900-LAHAINA.0 merged
    LA.UM.10.9.1.r1-00800-QCS610.0 merged
    Linux v5.4.174 merged
    Wi-Fi drivers updated to 2.0.8.26T
    2022-01-05 security patch merged
    Latest WireGuard merged
    Latest f2fs from Linux v5.17 merged
    Latest LRNG v43 merged
    Read-write semaphore backported from Linux v5.16 to improve smoothness under heavy I/O
    Now built with the latest Clang 13.0.2
    Disabled SLUB per-CPU partial caches for better latency (by Sultan)