From 8f850c7c6208776c0f6613cdd438cf92ffebb2ec Mon Sep 17 00:00:00 2001
From: Artturin <Artturin@artturin.com>
Date: Thu, 21 Nov 2024 01:06:03 +0200
Subject: [PATCH] Define hugepages mount in module

---
 flake.nix                     | 19 +++++++++++++++++++
 pkgs/system-tools/default.nix |  3 ++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/flake.nix b/flake.nix
index cd3840d..233f327 100644
--- a/flake.nix
+++ b/flake.nix
@@ -101,6 +101,25 @@
             systemd = {
               # https://github.com/NixOS/nixpkgs/issues/81138
               services.tenstorrent-hugepages.wantedBy = [ "sysinit.target" ];
+              # Define https://github.com/tenstorrent/tt-system-tools/blob/29ba4dc6049eef3cee4314c53720417823ffc667/dev-hugepages%5Cx2d1G.mount
+              # because it has bad start ordering relations with tenstorrent-hugepages.service
+              # or it may be that the `wantedBy` does not work correctly in mounts like it does't work in serices.
+              mounts = [
+                {
+                  description = "Mount hugepages at /dev/hugepages-1G for Tenstorrent ASICs";
+                  what = "hugetlbfs";
+                  where = "/dev/hugepages-1G";
+                  type = "hugetlbfs";
+                  options = "pagesize=1G,mode=0777,nosuid,nodev";
+                  wantedBy = [ "sysinit.target" ];
+                  after = [ "tenstorrent-hugepages.service" ];
+                  unitConfig = {
+                    DefaultDependencies = false;
+                    ConditionPathExists = "/sys/kernel/mm/hugepages/hugepages-1048576kB";
+                    ConditionCapability = "CAP_SYS_ADMIN";
+                  };
+                }
+              ];
               packages = [
                 (pkgs.tt-system-tools or self.packages.${pkgs.hostPlatform.system}.system-tools)
               ];
diff --git a/pkgs/system-tools/default.nix b/pkgs/system-tools/default.nix
index 0d99aac..53ef49b 100644
--- a/pkgs/system-tools/default.nix
+++ b/pkgs/system-tools/default.nix
@@ -33,7 +33,8 @@ stdenv.mkDerivation rec {
     runHook preInstall
 
     install -Dm444 -t $out/lib/systemd/system/ "tenstorrent-hugepages.service"
-    install -Dm444 -t $out/lib/systemd/system/ 'dev-hugepages\x2d1G.mount'
+    # Defined in the module
+    #install -Dm444 -t $out/lib/systemd/system/ 'dev-hugepages\x2d1G.mount'
     install -Dm555 -t $out/libexec/ "hugepages-setup.sh"
 
     runHook postInstall