From 1552eeca128b9be7c544ee1ad4a9385dd68ead31 Mon Sep 17 00:00:00 2001
From: Aleix Roca Nonell <aleix.rocanonell@bsc.es>
Date: Fri, 9 Jun 2023 10:58:11 +0200
Subject: [PATCH] xeon08: Add perf

---
 xeon08/kernel/kernel.nix |  1 +
 xeon08/kernel/perf.nix   | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+)
 create mode 100644 xeon08/kernel/perf.nix

diff --git a/xeon08/kernel/kernel.nix b/xeon08/kernel/kernel.nix
index ae3b91d..45ecce6 100644
--- a/xeon08/kernel/kernel.nix
+++ b/xeon08/kernel/kernel.nix
@@ -48,6 +48,7 @@ let
 in {
   imports = [
     ./lttng.nix
+    ./perf.nix
   ];
   boot.kernelPackages = lib.mkForce kernel;
 }
diff --git a/xeon08/kernel/perf.nix b/xeon08/kernel/perf.nix
new file mode 100644
index 0000000..51340df
--- /dev/null
+++ b/xeon08/kernel/perf.nix
@@ -0,0 +1,22 @@
+{ config, pkgs, lib, ... }:
+
+{
+  # add the perf tool
+  environment.systemPackages = with pkgs; [
+    config.boot.kernelPackages.perf
+  ];
+
+  # allow non-root users to read tracing data from the kernel
+  boot.kernel.sysctl."kernel.perf_event_paranoid" = -2;
+  boot.kernel.sysctl."kernel.kptr_restrict" = 0;
+
+  # specify additionl options to the tracefs directory to allow members of the
+  # tracing group to access tracefs.
+  fileSystems."/sys/kernel/tracing" = {
+    options = [
+      "mode=755"
+      "gid=tracing"
+    ];
+  };
+}
+