chickernel: stable-3 release

/*
* Your warranty is no longer valid, unless you lie.
*
* I am not responsible for bricked devices, strained relationships,
* 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.
*
*/

A kernel carefully optimized for

• low-memory, cpu, f2fs and scheduling performance
• battery and power savings

Speciifically crafted for 4GB variant in mind ❤️

• Supports tapas/topaz/sapphire/sapphiren ⭐

XDA Forums thread | SourceForge mirror

📋 Click here to see new changes introduced in this release

wakelocks:
- added boefla wakelock blocker, and blacklisted two wakelocks that are not suitable for android by default
- reduced wakelock timeouts for fingerprint and serial drivers

governor:
- blacklisted "userspace" and "ondemand" governors from loading as they are never used

iogovernor:
- added SSG I/O governor (used by samsung) and tuned it to increase throughput and reduce latency
- removed kyber and mq-deadline I/O governors as they are not used, and don't pose any advantage over existing ones

cpuidle:
- disabled "menu" and generic arm cpuidle governors in favor of governors that are more suitable on our platform (TEO, Qcom-LPM)

arm:
- improved performance of library routines by 20%
- used optimized arm helpers for zram, zsmalloc and F2FS to improve performance by around 10%

f2fs:
- disabled collection of statistics (iostat) by default to reduce latency

kernel:
- enabled power-efficient workqueues by default
- disabled deprecated armv8 instruction emulation since it is not used
- removed unused serial drivers that are not used on our platform
- stripped out assembler symbols, and miscellaneous debugging to reduce kernel size
- imported binder priority driver and tuned it to prioritize common UI renderers and elements

compilation:
- enabled the use of LLVM polyhedral optimizations 

📋 Click here to see changelog from previous release(s)

mm: 
- mlgru: enable mlgru by default to reduce app killings in background

usb:
- fix usb tethering - stop system from panicking upon enabling usb-tethering in android settings

wakelocks:
- add timeout to wakelocks to stop system from not entering deep-sleep at all
- alarmtimer: minimize wakeup time to reduce power consumption
- avoid excessive and unnecessary wakeup attempts

sched:
- cass: add capacity aware superset scheduler (CASS) to improve single-core performance and latency
- fair: reduce PELT half-life time to increase interactivity
- core: reduce overhead and latency

net:
- set google's 'BBR' as the default TCP congestion algorithm to improve network performance
- add 'westwood' TCP congestion algorithm for users who prefer it
- use fq_codel by default

freezer: 
- reduce freeze timeout to avoid draining battery unnecessarily

governor: 
- make 'performance' the default CPU governor to improve boot performance - this will be reverted once boot completes anyway

mm:
- reduce swappiness to 35 since we have mlgru enabled to reduce aggressive swapping and reduce power consumption
- disable watermark boosting as it's a mess, and hurts performance on low-memory devices
- don't hog the CPU and zone lock in rmqueue_bulk to reduce system latency
- lower the non-hugetlbpage pageblock size to reduce scheduling delays
- micro-optimize PID maps
- stop kswapd when it is not needed to save resources.
- reduce measurable overhead

cpuidle: 
- add timer to stop wi-fi from staying idle to reduce power consumption
- prioritize 'teo' over 'menu' scheduler
- minor optimizations

f2fs:
- force fsync for better data integrity and lower data corruption risk
- reduce timeout for uncongestion to lower I/O latency
- reduce GC thread urgent sleep time to 50ms to improve performance on unencrypted system
- enlarge min_fsync_blocks to 20 to improve fsync performance
- enable ATGC and GC_MERGE by default to improve efficiency of garbage collection

rcu:
- enable lazy-rcu by default to increase battery savings on idle or low system load
- panic on RCU stall so we don't have to restart on deadlock manually
- minor optimizations

arm: 
- assign unbound workqueues to little CPU cluster by default to reduce power consumption
- import new optimized strcmp from ARM (manufacturer)
- disable legacy 16-bit calls support to reduce kernel image size

anykernel3: 
- support sapphire/sapphiren 

compilation: 
- compile with clang -O3 optimizations for maximal performance
- tune our compiler specifically for sm6225-AD to achieve bigger performance improvements
- bump clang from 18.0.1 -> 19.0.0

kernel:
- disable profiling support so we can reduce the kernel size
- unselect unrelated platform support to reduce kernel size 
- unselect unneeded errata workarounds not affecting our SoC to improve performance
- build `ZRAM` and `ZSMALLOC` modules into the kernel image, as most of the time, the external modules are outdated

debug: 
- binder: disable debugging and logging prints to reduce wasted cycles
- arm64: disable self-hosted debug by default

merged:
- CAF (Qualcomm) changes
- Xiaomi changes

This is a stable 5.15 release built with latest clang-19.0.0 (-O3 and polyhedral optimizations)

Installation guide:

1. Download the kernel zip below
2. Reboot to recovery and install it
3. Enjoy

Credits

• Google, for android common kernel (ACK)
• kerneltoast, for his awesome work & commits
• panchajanya1999, for few commits
• ztc1997, for ideas & some commits
• OrionG2 on XDA, for testing

⚠️ Report any bugs and problems here

Please, if you Ctrl-C + Ctrl-V my kernel, at least provide some credit for my efforts

---