powertop: add module

nixos/modules/module-list.nix

@@ -659,6 +659,7 @@
   ./tasks/scsi-link-power-management.nix
   ./tasks/swraid.nix
   ./tasks/trackpoint.nix
+  ./tasks/powertop.nix
   ./testing/service-runner.nix
   ./virtualisation/container-config.nix
   ./virtualisation/containers.nix

nixos/modules/tasks/powertop.nix

@@ -0,0 +1,27 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.powerManagment.powertop;
+in {
+  ###### interface
+
+  options.powerManagment.powertop.enable = mkEnableOption "powertop auto tuning on startup";
+
+  ###### implementation
+
+  config = mkIf (cfg.enable) {
+    systemd.services = {
+      powertop = {
+        wantedBy = [ "multi-user.target" ];
+        description = "Powertop tunings";
+        serviceConfig = {
+          Type = "oneshot";
+          RemainAfterExit = "yes";
+          ExecStart = "${pkgs.powertop}/bin/powertop --auto-tune";
+        };
+      };
+    };
+  };
+}