zswap

hosts/flubber-machine/default.nix

@@ -93,6 +93,7 @@
       system.flatpak.enable = true;
       system.mpv.enable = true;
       system.ananicy.enable = true;
+      system.zswap.enable = true;
       system.kdeconnect.enable = true;
       # editors
       editors.micro.enable = true;

modules/software/system/zswap.nix

@@ -0,0 +1,20 @@
+{ lib, config, pkgs, ... }:
+
+with lib;
+let
+  cfg = config.modules.software.system.zswap;
+in {
+  options.modules.software.system.zswap = {
+    enable = mkEnableOption "Enable zswap, a compressed RAM cache for swap pages";
+  };
+
+  config = mkIf cfg.enable {
+    boot.kernelParams = [
+      "zswap.enabled=1"
+      "zswap.shrinker_enabled=1" # high mem: shrink zswap, mv to swap
+      "zswap.max_pool_percent=20" # TODO: tune this (keep in mind shrinker is enabled)
+      "zswap.compressor=zstd" # lz4 is missing for some reason
+      "zswap.zpool=zsmalloc"
+    ];
+  };
+}