Nexus Changelog 15/03/2023

- Merged 4.19.277 upstream from ACK.

- Merged Latest clo tag (LA.UM.9.12.r1-15200.02-SMxx50.0).

- Disabled Ipa wakelocks (Improves deep sleep).

- Updated vdso & vdso32.

- Resolved sched_feat() at compile time to improve code optimization.

- Enabled Write Back Caching.

- Changed to efficient freqs.

- Enabled PM_WAKELOCKS_GC.

- Reverted cfq patches (Decreases power usage).

- Micro optimized cfq.

- Added Zstd compressor.

- alarmtimer: Added ndelay for tight loop (To avoid potential scheduling delays due to IRQ stalling).

- Enabled WQ_HIGHPRI on verify_wq (The average time to open the camera is reduced by 350ms (or 40-50%)).

- Stop using WQ_UNBOUND for verify_wq (Setting WQ_UNBOUND increases scheduler latency on ARM64).

- Removed unsupported crypto extensions for kona.

- Removed unused compressors (Zbud and Zpool).

- Decreased dynamic memory allocations and leaks on camera side(To avoid stutters).

- Skip heavy autorefresh checks when it's not enabled (Wastes alot of cpu cycles).

- Disabled Spectre-BHB mitigation (It brings overhead).

- Disabled CPU Isolation (Impacts performance and cpu hotplugging).

- Nuked useless logspams.