Bug-589744-Fallback-to-perf-measurement-stub-when-pe.patch

From: Mike Hommey <mh+mozilla@glandium.org>
Date: Mon, 21 Mar 2011 18:31:12 +0100
Subject: Bug 589744 - Fallback to perf measurement stub when perf_event_open
 syscall isn't supported. r=ted

---
 js/src/configure.in |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

--- a/js/src/configure.in
+++ b/js/src/configure.in
@@ -3477,7 +3477,16 @@ case $target in
 esac
 
 dnl Performance measurement headers.
-AC_CHECK_HEADER(linux/perf_event.h, HAVE_LINUX_PERF_EVENT_H=1)
+AC_CHECK_HEADER(linux/perf_event.h,
+    [AC_CACHE_CHECK(for perf_event_open system call,ac_cv_perf_event_open,
+        [AC_TRY_COMPILE([#include <sys/syscall.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=
+fi
 AC_SUBST(HAVE_LINUX_PERF_EVENT_H)
 
 dnl Checks for libraries.