From d3979b659cb385597baecf5518a614089b489424 Mon Sep 17 00:00:00 2001
From: Vladimir Still <vl.still@gmail.com>
Date: Fri, 7 Feb 2014 22:53:55 +0100
Subject: [PATCH] perf: Make build fix for 3.13 cleaner.

---
 pkgs/os-specific/linux/kernel/perf.nix | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/pkgs/os-specific/linux/kernel/perf.nix b/pkgs/os-specific/linux/kernel/perf.nix
index f486f55654e6..a7337760b79e 100644
--- a/pkgs/os-specific/linux/kernel/perf.nix
+++ b/pkgs/os-specific/linux/kernel/perf.nix
@@ -4,6 +4,9 @@
 
 assert withGtk -> gtk != null;
 
+let optionalString = stdenv.lib.optionalString;
+    versionOlder = stdenv.lib.versionOlder;
+in
 stdenv.mkDerivation {
   name = "perf-linux-${kernel.version}";
 
@@ -12,7 +15,7 @@ stdenv.mkDerivation {
   preConfigure = ''
     cd tools/perf
     sed -i s,/usr/include/elfutils,$elfutils/include/elfutils, Makefile
-    patch -p1 < ${./perf.diff} || true
+    ${optionalString (versionOlder kernel.version "3.13") "patch -p1 < ${./perf.diff}"}
     [ -f bash_completion ] && sed -i 's,^have perf,_have perf,' bash_completion
     export makeFlags="DESTDIR=$out $makeFlags"
   '';