diff -r 000000000000 -r 6474c204b198 build/autoconf/linux.m4
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/build/autoconf/linux.m4	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,39 @@
+dnl This Source Code Form is subject to the terms of the Mozilla Public
+dnl License, v. 2.0. If a copy of the MPL was not distributed with this
+dnl file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+AC_DEFUN([MOZ_LINUX_PERF_EVENT],
+[
+
+MOZ_ARG_WITH_STRING(linux-headers,
+[  --with-linux-headers=DIR
+                          location where the Linux kernel headers can be found],
+    linux_headers=$withval)
+
+LINUX_HEADERS_INCLUDES=
+
+if test "$linux_headers"; then
+    LINUX_HEADERS_INCLUDES="-I$linux_headers"
+fi
+
+_SAVE_CFLAGS="$CFLAGS"
+CFLAGS="$CFLAGS $LINUX_HEADERS_INCLUDES"
+
+dnl Performance measurement headers.
+MOZ_CHECK_HEADER(linux/perf_event.h,
+    [AC_CACHE_CHECK(for perf_event_open system call,ac_cv_perf_event_open,
+        [AC_TRY_COMPILE([#include <asm/unistd.h>],[return sizeof(__NR_perf_event_open);],
+        ac_cv_perf_event_open=yes,
+        ac_cv_perf_event_open=no)])])
+if test "$ac_cv_perf_event_open" = "yes"; then
+    HAVE_LINUX_PERF_EVENT_H=1
+else
+    HAVE_LINUX_PERF_EVENT_H=
+    LINUX_HEADERS_INCLUDES=
+fi
+AC_SUBST(HAVE_LINUX_PERF_EVENT_H)
+AC_SUBST(LINUX_HEADERS_INCLUDES)
+
+CFLAGS="$_SAVE_CFLAGS"
+
+])