test earlyoom

base.nix

@@ -73,6 +73,10 @@
   # enable kernel same-page merging for improved vm test performance
   hardware.ksm.enable = true;
 
+  # enable Alt+SysRq+<key> shortcuts
+  # https://wiki.nixos.org/wiki/Linux_kernel#Enable_SysRq
+  # boot.kernel.sysctl."kernel.sysrq" = 1;
+
   boot.initrd.systemd.enable = true; # systemd manages initfs boot, systemd-analyse can see what happened
   # https://discourse.nixos.org/t/what-to-do-with-a-full-boot-partition/2049
   # raise to 15 if auto upgrading

hosts/nixos/sopp/configuration.nix

@@ -45,6 +45,7 @@
   imports = [
     ./hardware-configuration.nix
     ../../../profiles/sshd
+    ../../../profiles/earlyoom.nix
     ../../../profiles/no-suspend.nix
     #../../../profiles/oci/podman.nix
     ../../../profiles/oci/docker.nix

profiles/earlyoom.nix

@@ -0,0 +1,16 @@
+{
+  services.earlyoom = {
+    enable = true;
+    # all must be true for earlyoom to kill shit
+    freeMemThreshold = 2; # in percent
+    freeSwapThreshold = 20; # in percent
+    freeSwapKillThreshold = 5; # in percent, sigkill
+    extraArgs = [
+      # "-g" # Kill all processes that have same process group id
+      "--avoid"
+      "^(X|init|Xorg|ssh|plasma.*|gnome.*|konsole|lxterminal|ghostty|kwin)$"
+      "--prefer"
+      "^(electron|libreoffice|gimp|zen*|nix-env|nix-instantiate|gcc|rustc)$"
+    ];
+  };
+}