Add AMD uProf module and enable it in fox

Reviewed-by: Aleix Boné <abonerib@bsc.es>

m/fox/configuration.nix

@@ -4,6 +4,7 @@
   imports = [
     ../common/base.nix
     ../common/xeon/console.nix
+    ../module/amd-uprof.nix
     ../module/emulation.nix
     ../module/nvidia.nix
     ../module/slurm-client.nix
@@ -29,6 +30,8 @@
   # Use performance for benchmarks
   powerManagement.cpuFreqGovernor = "performance";
 
+  services.amd-uprof.enable = true;
+
   # Disable NUMA balancing
   boot.kernel.sysctl."kernel.numa_balancing" = 0;
 

m/module/amd-uprof.nix

@@ -0,0 +1,49 @@
+{ config, lib, pkgs, ... }:
+
+{
+  options = {
+    services.amd-uprof = {
+      enable = lib.mkOption {
+        type = lib.types.bool;
+        default = false;
+        description = "Whether to enable AMD uProf.";
+      };
+    };
+  };
+
+  # Only setup amd-uprof if enabled
+  config = lib.mkIf config.services.amd-uprof.enable {
+
+    # First make sure that we add the module to the list of available modules
+    # in the kernel matching the same kernel version of this configuration.
+    boot.extraModulePackages = with config.boot.kernelPackages; [ amd-uprof-driver ];
+    boot.kernelModules = [ "AMDPowerProfiler" ];
+
+    # Make the userspace tools available in $PATH.
+    environment.systemPackages = with pkgs; [ amd-uprof ];
+
+    # The AMDPowerProfiler module doesn't create the /dev device nor it emits
+    # any uevents, so we cannot use udev rules to automatically create the
+    # device. Instead, we run a systemd unit that does it after loading the
+    # modules.
+    systemd.services.amd-uprof-device = {
+      description = "Create /dev/AMDPowerProfiler device";
+      after = [ "systemd-modules-load.service" ];
+      wantedBy = [ "multi-user.target" ];
+      unitConfig.ConditionPathExists = [
+          "/proc/AMDPowerProfiler/device"
+          "!/dev/AMDPowerProfiler"
+      ];
+      serviceConfig = {
+        Type = "oneshot";
+        RemainAfterExit = true;
+        ExecStart = pkgs.writeShellScript "add-amd-uprof-dev.sh" ''
+          mknod /dev/AMDPowerProfiler -m 666 c $(< /proc/AMDPowerProfiler/device) 0
+        '';
+        ExecStop = pkgs.writeShellScript "remove-amd-uprof-dev.sh" ''
+          rm -f /dev/AMDPowerProfiler
+        '';
+      };
+    };
+  };
+}