--- perf	2010-04-16 22:58:56.000000000 +1000
+++ perf.fixed	2010-04-27 11:56:51.231589728 +1000
@@ -1,4 +1,11 @@
 #!/bin/bash
 version=`uname -r`
 version=${version%-*}
-exec "perf_$version" "$@"
+tool="perf_$version"
+if ! which "$tool" > /dev/null
+then
+	echo "$tool not found" >&2
+	echo "you may need to install linux-tools-$version" >&2
+	exit 2
+fi
+exec "$tool" "$@"