nixpkgs/nixos/modules/hardware/ksm.nix
rnhmjoj 48052ca0dd
nixos/ksm: remove udev-settle dependency
The sysfs file /sys/kernel/mm/ksm/run seems to be available as soon as
the kernel has started, so no point in waiting for udev to "settle". If
for some reason it doesn't, we let the unit fail explicitly.
2021-02-26 22:10:10 +01:00

39 lines
919 B
Nix

{ config, lib, ... }:
with lib;
let
cfg = config.hardware.ksm;
in {
imports = [
(mkRenamedOptionModule [ "hardware" "enableKSM" ] [ "hardware" "ksm" "enable" ])
];
options.hardware.ksm = {
enable = mkEnableOption "Kernel Same-Page Merging";
sleep = mkOption {
type = types.nullOr types.int;
default = null;
description = ''
How many milliseconds ksmd should sleep between scans.
Setting it to <literal>null</literal> 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
'';
};
};
}