nixpkgs/nixos/modules/hardware/ksm.nix

39 lines
930 B
Nix

{ config, lib, ... }:
with lib;
let
cfg = config.hardware.ksm;
in {
imports = [
(mkRenamedOptionModule [ "hardware" "enableKSM" ] [ "hardware" "ksm" "enable" ])
];
options.hardware.ksm = {
enable = mkEnableOption (lib.mdDoc "Linux kernel Same-Page Merging");
sleep = mkOption {
type = types.nullOr types.int;
default = null;
description = lib.mdDoc ''
How many milliseconds ksmd should sleep between scans.
Setting it to `null` uses the kernel's default time.
'';
};
};
config = mkIf cfg.enable {
systemd.services.enable-ksm = {
description = "Enable Kernel Same-Page Merging";
wantedBy = [ "multi-user.target" ];
script =
''
echo 1 > /sys/kernel/mm/ksm/run
'' + optionalString (cfg.sleep != null)
''
echo ${toString cfg.sleep} > /sys/kernel/mm/ksm/sleep_millisecs
'';
};
};
}