Global USE flags

Flag Description Packages
hardened Require CachyOS kernel sources with hardened patches 3

Category USE flags

sys-kernel

Flag Description Packages
autofdo Enable Clang AutoFDO (Automatic Feedback-Directed Optimization) support for profile-guided optimization 2
bbr3 Enable TCP BBR3 (Bottleneck Bandwidth and RTT) congestion control algorithm as default 2
bmq Project C BMQ scheduler 2
bmq-lfbmq PRJC BMQ scheduler with the LFBMQ (lock-free bitmap queue) runqueue variant from kernel-patches 2
bore CachyOS Scheduler (BORE - Burst-Oriented Response Enhancer), optimized for desktop responsiveness 3
cachyos-hardened Enable the CachyOS hardened kernel variant and patchset 3
debug Enable debug-friendly optimizations and disable various debug features 3
deckify Apply the upstream handheld and ACPI patchsets and enable Steam Deck, ASUS Ally, Lenovo Go, MSI Claw, and ZOTAC Zone support with the selected scheduler 3
eevdf Linux EEVDF scheduler with the CachyOS POC idle CPU selector 3
hugepage_always Always enable Transparent Huge Pages for better memory performance 2
hugepage_madvise Enable Transparent Huge Pages only when requested via madvise 2
hz_ticks_100 Set kernel timer frequency to 100 Hz (server/battery optimized) 2
hz_ticks_1000 Set kernel timer frequency to 1000 Hz (desktop optimized, default) 2
hz_ticks_250 Set kernel timer frequency to 250 Hz (balanced) 2
hz_ticks_300 Legacy 300 Hz flag used by older ebuilds 2
hz_ticks_500 Set kernel timer frequency to 500 Hz 2
hz_ticks_600 Legacy 600 Hz flag used by older ebuilds 2
hz_ticks_750 Legacy 750 Hz flag used by older ebuilds 2
kcfi Enable kCFI (Kernel Control Flow Integrity) for additional security protection (requires clang) 2
kernel-builtin-zfs Build ZFS module directly into the kernel (not recommended, use sys-fs/zfs-kmod instead) 2
llvm-lto-full Enable LLVM full LTO - single threaded, slower compilation, more memory usage, potentially highest performance 2
llvm-lto-none Disable LLVM link-time optimization 2
llvm-lto-thin Enable LLVM thin LTO (Link Time Optimization) - uses multiple threads, faster compilation, less memory usage 2
llvm-lto-thin-dist Enable LLVM thin LTO with distributed model rather than in-process linking 2
mgeneric Use generic x86-64 optimizations (default kernel optimizations, portable across machines) 2
mgeneric_v1 Use x86-64-v1 generic optimizations (baseline x86-64) 2
mgeneric_v2 Use x86-64-v2 generic optimizations (requires CMPXCHG16B, LAHF-SAHF, POPCNT, SSE3, SSE4.1, SSE4.2, SSSE3) 2
mgeneric_v3 Use x86-64-v3 generic optimizations (requires AVX, AVX2, BMI1, BMI2, F16C, FMA, LZCNT, MOVBE, XSAVE) 2
mgeneric_v4 Use x86-64-v4 generic optimizations (requires AVX512F, AVX512BW, AVX512CD, AVX512DQ, AVX512VL) 2
mnative Use compiler native CPU autodetection optimizations (recommended for local builds, not portable) 2
muqss MuQSS scheduler patchset carried in CachyOS kernel-patches 2
mzen4 Use the AMD Zen 4 CPU target 2
o3 Optimize the kernel with -O3 2
os Optimize for size (-Os) instead of performance 2
per-gov Use the performance CPU frequency governor by default 2
preempt_full Full preemption model for lowest latency (PREEMPT) 2
preempt_lazy Lazy preemption model (PREEMPT_LAZY) 2
propeller Enable Clang Propeller optimization (basic block reordering) for better performance 2
rt EEVDF scheduler with realtime patches for low-latency applications 2
rt-bore BORE scheduler with realtime patches for low-latency applications 3
server Apply the upstream server preset: EEVDF, 300 Hz, lazy preemption, no LTO, and CachyOS config tweaks disabled 3
tickrate_full Use full tickless mode (NO_HZ_FULL) - can provide higher performance but lower consistency depending on hardware 2
tickrate_idle Use idle tickless mode (NO_HZ_IDLE) 2
tickrate_periodic Use periodic ticks (traditional approach) 2

Local USE flags

app-admin

ananicy-cpp

Flag Description
systemd

cachyos-settings

Flag Description
X
zram

sys-kernel

cachyos-kernel

Flag Description
clang Build the kernel using Clang/LLVM toolchain instead of GCC (required for LTO and KCFI)

cachyos-kernel-bin

Flag Description
cachyos Default CachyOS kernel variant
gcc Use the GCC-compiled build variant (default scheduler only, no LTO)
lto Use the Clang ThinLTO build variant for better runtime performance
lts Long-term support kernel variant

cachyos-sources

Flag Description
hugepage-always Always enable transparent huge pages
hugepage-madvise Enable transparent huge pages only when requested with madvise
hz-ticks-100 Set the kernel timer frequency to 100 Hz
hz-ticks-1000 Set the kernel timer frequency to 1000 Hz
hz-ticks-250 Set the kernel timer frequency to 250 Hz
hz-ticks-300 Set the kernel timer frequency to 300 Hz
hz-ticks-500 Set the kernel timer frequency to 500 Hz
hz-ticks-600 Set the kernel timer frequency to 600 Hz
hz-ticks-750 Set the kernel timer frequency to 750 Hz
mgeneric-v1 Use the x86-64-v1 CPU target
mgeneric-v2 Use the x86-64-v2 CPU target
mgeneric-v3 Use the x86-64-v3 CPU target
mgeneric-v4 Use the x86-64-v4 CPU target
preempt-full Use the full preemption model
preempt-lazy Use the lazy preemption model
tickrate-full Use full tickless mode
tickrate-idle Use idle tickless mode
tickrate-periodic Use periodic kernel ticks

virtual

linux-sources

Flag Description
firmware Install linux kernel firmware