From 1b9b85556942e6cf3add12206d2acf7c313028ca Mon Sep 17 00:00:00 2001
From: Mitchell Pleune <mitchpleune@gmail.com>
Date: Sun, 8 Dec 2024 22:56:33 -0500
Subject: [PATCH] nixos/iotop: optionally enable delayacct tracking in kernel

Since Linux commit e4042ad492357fa995921376462b04a025dd53b6 (May 2021)
this is disabled by default as it is "not used much."
---
 nixos/modules/programs/iotop.nix | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/nixos/modules/programs/iotop.nix b/nixos/modules/programs/iotop.nix
index 1d18edf3d9f8..f985a9023862 100644
--- a/nixos/modules/programs/iotop.nix
+++ b/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; };
   };
 }