Seg/gaming performance

.github/workflows/ci.yml

@@ -79,10 +79,17 @@ jobs:
       # Without the test cfg, where unwrap and expect are compile errors.
       - run: cargo clippy --locked -- -D warnings
       - run: cargo test --locked
-      - name: Dependencies stay minimal (seg and lexopt only)
+      - name: Dependencies stay minimal (seg, lexopt and libc only)
         run: |
           cargo tree --locked -e normal --prefix none | sort -u
-          test "$(cargo tree --locked -e normal --prefix none | sort -u | wc -l)" -le 2
+          test "$(cargo tree --locked -e normal --prefix none | sort -u | wc -l)" -le 3
+      # The only unsafe code is the few libc calls of src/game/proc.rs.
+      - name: unsafe stays in one file
+        run: |
+          test "$(grep -rEl '\bunsafe[[:space:]]*(\{|fn|impl|extern)' segctl/src)" = "segctl/src/game/proc.rs"
+      - name: sudoers rule is valid
+        run: |
+          sudo visudo -cf dist/sudoers-seg-game
       - name: Release binary size
         run: |
           cargo build --locked --release
@@ -106,7 +113,7 @@ jobs:
             data/desktop/labwc/autostart data/system/seglinux-terminal data/system/restore-trimmed-files \
             data/system/profile-gaming.sh data/greeter/seglinux-greeter-session data/system/zram-setup \
             tools/seg/dist/fstrim-weekly tools/seg/dist/runit/*/run tools/seg/dist/runit/seg-zram/finish \
-            tools/seg/dist/openrc/seg-tune tools/seg/dist/openrc/seg-zram
+            tools/seg/dist/openrc/seg-tune tools/seg/dist/openrc/seg-zram tools/seg/dist/openrc/seg-game
           shellcheck -s bash pkg/segctl/segctl.install
           shellcheck -s bash iso/iso-profiles/seglinux-lite/live-overlay/etc/skel/.bash_profile
       - name: YAML, JSON and XML syntax
@@ -200,7 +207,9 @@ jobs:
           pacman-key --populate artix
           pacman -Sy --noconfirm --needed go-yq
           iso/scripts/chaotic-aur.sh
-      - run: iso/scripts/check-packages.sh -p ${{ matrix.profile }} -i ${{ matrix.init }} -k linux-zen
+      # -x: the packages `seg game setup` can choose (NVIDIA's driver, the
+      # Vulkan drivers, the games stack) must exist and resolve on top of the image.
+      - run: iso/scripts/check-packages.sh -p ${{ matrix.profile }} -i ${{ matrix.init }} -k linux-zen -x tools/seg/segctl/tests/setup-packages.txt
       - name: Packages the Lite edition downloads during Setup
         if: matrix.profile == 'seglinux-lite'
         run: iso/scripts/online-packages.sh -i openrc -k linux-zen

CHANGELOG.md

@@ -0,0 +1,88 @@
+# Changelog
+
+Notable changes to SegLinux. The project has no version numbers yet, so this
+lists what changed since the last ISO build of 19 October 2026 (`4ca2f45`).
+Measurements and the reasons behind each removal are in
+[docs/lean-audit.md](docs/lean-audit.md).
+
+## Unreleased
+
+### Added
+
+- **`seg game`**, a small gaming layer in the `seg` tool, the same on OpenRC,
+  runit, dinit and s6 ([docs/gaming.md](docs/gaming.md#seg-game)):
+  - `seg game run -- CMD` (Steam: `seg game run -- %command%`) raises the CPU
+    governor and energy preference and an AMD GPU's power level while a game
+    runs, gives the game a little more CPU and the best I/O priority, holds
+    off the screen saver, can pin it to the V-Cache chiplet of a two-chiplet
+    X3D CPU, and restores everything when the game ends, on Ctrl+C, SIGTERM,
+    SIGHUP or a crash of `seg`.
+  - `seg game check`: PASS/WARN/FAIL/SKIP for Vulkan, the GPU driver, 32-bit
+    drivers, NTSYNC, `vm.max_map_count`, open files, kernel, fallback kernel,
+    CPU governor and driver, boost permission, hugepages, split lock,
+    compaction and mitigations, each with the exact fix.
+  - `seg game setup [--yes]`: the driver packages for the GPUs found in the
+    computer, and only those.
+  - `seg game profiles`, per-game profiles in `~/.config/seg/games.toml`
+    (governor, CPU pinning, MangoHud, gamescope arguments, nice).
+  - `seg game apply` and the **`seg-game` service** (OpenRC, runit, dinit,
+    s6): the gaming sysctls and `/dev/ntsync` permissions at boot.
+  - `seg game audio on|off`: low-latency PipeWire, off by default.
+  - `seg game unsafe-boost on|off`: `mitigations=off`, the only way to get
+    it, behind a warning and `--i-understand`.
+  - `seg tune gaming`: low swappiness, warm caches, short write-back, CPU
+    left dynamic.
+  - A sudoers rule for the `gamemode` group (two commands, nothing else), a
+    MangoHud preset and PipeWire drop-ins under `/usr/share/seg` (all off
+    until asked for).
+- Setup installs the **other kernel** (`linux` beside `linux-zen`, or the
+  reverse) as a boot menu entry to fall back on when online
+  (`[performance] fallback_kernel`); the installed kernel is never removed.
+- Kernel command line: `transparent_hugepage=madvise` everywhere and
+  `amd_pstate=active` on AMD processors (an answer file's parameter of the
+  same name replaces the default).
+- `vm.compaction_proactiveness = 0` with the other gaming sysctls.
+- NVIDIA: `nvidia_drm modeset=1 fbdev=1` (Wayland compositors, VT switch).
+- `seg` (`tools/seg`, package `segctl`): `info`, `svc`, `clean`, `tune`,
+  `zram`, `doctor` for OpenRC, runit, dinit and s6, with the `seg-zram` and
+  `seg-tune` services and a weekly `fstrim` cron job.
+- `ripgrep`, `fd`, `eza` and `zoxide` in the full edition.
+- `docs/lean-audit.md`: what the images weigh before and after, the bloat
+  table, the bugs found, what was not verified.
+- CI: a job for `seg` (fmt, clippy, tests, release size, dependency and
+  `unsafe` guards, `visudo -cf` of the sudoers rule), `udevadm verify` for
+  the udev rules, a check for repeated packages, more `shellcheck` targets.
+
+### Changed
+
+- `wine` -> `wine-staging` (the Staging patches: esync/fsync/NTSYNC, game
+  fixes) in the full edition. `lib32-mangohud` was tried and is not in the
+  Artix repositories, so 32-bit games get no MangoHud overlay.
+- Open-file hard limit 524288 -> 1048576 (the kernel's maximum); the
+  `gamemode` group may use `nice -10`.
+- Shader caches: Mesa 4 GB -> 10 GB; NVIDIA's shader cache set to 10 GB and
+  no longer deleted when full (`/etc/profile.d`, so on every init).
+- `makepkg` builds with every thread; the I/O scheduler rule skips partitions
+  and covers virtual disks.
+
+### Removed
+
+- From the full image: `linux-headers` (325 MiB; Setup downloads the running
+  kernel's headers together with the NVIDIA DKMS driver), `spectacle` and
+  `opencv`, the X server and its drivers (`xorg-xwayland` stays), `inxi`,
+  and five packages that were listed twice. The full ISO is 4.7 % smaller and
+  475 MiB less is installed.
+- `cupsd` is no longer started by default (the packages stay; `seg svc enable
+  cupsd`).
+
+### Fixed
+
+- The NVIDIA DKMS driver could only build because the headers were on every
+  image: Setup now installs them in that step.
+- The artools patch that reads the kernel version without headers applies to
+  every kernel, not only the non-stock ones.
+- The I/O scheduler udev rule matched partitions (errors in the log) and
+  missed virtual disks.
+- `data/system/zram-setup` and the udev rules were not checked by CI.
+- `seg doctor` called OpenRC services of the `shutdown` runlevel (`killprocs`,
+  `mount-ro`, `savecache`) failed; found by booting the Lite image.

README.md

@@ -90,11 +90,15 @@ published.
   kitty as the terminal (File Explorer → Dolphin, Store → Discover, ...).
   The terminal opens with system information under the SegLinux logo
   (fastfetch).
-* **Built for gaming.** linux-zen kernel, Steam with Proton, Lutris,
-  GameMode, MangoHud and gamescope; a Steam "Gaming Mode" session; variable
-  refresh rate and tearing for fullscreen games; zram swap, NTSYNC, I/O
-  scheduler and sysctl tuning; NVIDIA's driver installed automatically on
-  GeForce GTX 16/RTX cards. See [docs/gaming.md](docs/gaming.md).
+* **Built for gaming.** linux-zen kernel (with the stock kernel beside it to
+  fall back on), Steam with Proton, Lutris, Wine Staging, GameMode, MangoHud
+  and gamescope; a Steam "Gaming Mode" session; variable refresh rate and
+  tearing for fullscreen games; zram swap, NTSYNC, I/O scheduler and sysctl
+  tuning; NVIDIA's driver installed automatically on GeForce GTX 16/RTX
+  cards, and only for hardware that is there. `seg game run -- %command%` in
+  Steam's launch options boosts the CPU and GPU while a game runs and puts
+  everything back after; `seg game check` says what is missing, with the
+  fix. See [docs/gaming.md](docs/gaming.md).
 * **Runs Windows programs.** Double-click an `.exe`, `.msi`, `.lnk` or
   `.bat`, or type `./setup.exe`: `segrun` inspects the program, prepares a
   Wine prefix (with DXVK/VKD3D-Proton when the program uses Direct3D) and
@@ -103,10 +107,12 @@ published.
   or dinit; rolling release.
 * **`seg`, one small tool for the system.** `seg info`, `seg svc` (the same
   commands on OpenRC, runit, dinit and s6), `seg clean`, `seg tune`
-  (light, balanced or performance), `seg zram` and `seg doctor`, which finds
-  problems and prints their fixes. A single Rust binary of about 550 KiB; see
+  (light, balanced, gaming or performance), `seg zram`, `seg game` (see
+  above) and `seg doctor`, which finds problems and prints their fixes. A
+  single Rust binary of about 700 KiB; see
   [tools/seg](tools/seg/README.md). What the images weigh and what was taken
-  off them: [docs/lean-audit.md](docs/lean-audit.md).
+  off them: [docs/lean-audit.md](docs/lean-audit.md). What changed:
+  [CHANGELOG.md](CHANGELOG.md).
 
 ## Website
 

crates/seglinux-installer/src/model.rs

@@ -201,6 +201,7 @@ pub fn demo_facts() -> Facts {
         memory: 8 * GIB,
         gpus: vec![],
         kernel: Some("linux-zen".into()),
+        cpu_vendor: None,
         timezones: Some(set(&[
             "UTC",
             "Africa/Tunis",