Merge pull request #259066 from thiagokokada/add-renice-sway

nixos/sway: add enableRealtime option

1 files changed, 13 insertions, 0 deletions

diff --git a/nixos/modules/programs/wayland/sway.nix b/nixos/modules/programs/wayland/sway.nix
index 698d9c2b46c4..de739faabee9 100644
--- a/nixos/modules/programs/wayland/sway.nix
+++ b/nixos/modules/programs/wayland/sway.nix
@@ -42,6 +42,11 @@ in {
       <https://github.com/swaywm/sway/wiki> and
       "man 5 sway" for more information'');
 
+    enableRealtime = mkEnableOption (lib.mdDoc ''
+      add CAP_SYS_NICE capability on `sway` binary for realtime scheduling
+      privileges. This may improve latency and reduce stuttering, specially in
+      high load scenarios'') // { default = true; };
+
     package = mkOption {
       type = with types; nullOr package;
       default = defaultSwayPackage;
@@ -149,6 +154,14 @@ in {
             "sway/config".source = mkOptionDefault "${cfg.package}/etc/sway/config";
           };
         };
+        security.wrappers = mkIf (cfg.enableRealtime && cfg.package != null) {
+          sway = {
+            owner = "root";
+            group = "root";
+            source = "${cfg.package}/bin/sway";
+            capabilities = "cap_sys_nice+ep";
+          };
+        };
         # To make a Sway session available if a display manager like SDDM is enabled:
         services.xserver.displayManager.sessionPackages = optionals (cfg.package != null) [ cfg.package ]; }
       (import ./wayland-session.nix { inherit lib pkgs; })