Add option to enable iotop with delayacct tracking in kernel (#363452)

nixos/modules/programs/iotop.nix

@@ -12,9 +12,15 @@ in
   options = {
     programs.iotop = {
       enable = lib.mkEnableOption "iotop + setcap wrapper";
+
       package = lib.mkPackageOption pkgs "iotop" { example = "iotop-c"; };
+
+      enableDelayacct = lib.mkEnableOption ''
+        the task_delayacct kernel task delay accounting in order to show all
+        statistics'';
     };
   };
+
   config = lib.mkIf cfg.enable {
     security.wrappers.iotop = {
       owner = "root";
@@ -22,5 +28,7 @@ in
       capabilities = "cap_net_admin+p";
       source = lib.getExe cfg.package;
     };
+
+    boot.kernel.sysctl = lib.mkIf cfg.enableDelayacct { "kernel.task_delayacct" = 1; };
   };
 }