diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index 6f6f13a13bb6..74f52d8f9631 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -1,3 +1,10 @@
+#
+# This is a simple wrapper Makefile that calls the main Makefile.perf
+# with a -j option to do parallel builds
+#
+# If you want to invoke the perf build in some non-standard way then
+# you can use the 'make -f Makefile.perf' method to invoke it.
+#
 
 #
 # Clear out the built-in rules GNU make defines by default (such as .o targets),
@@ -5,6 +12,11 @@
 #
 .SUFFIXES:
 
+#
+# We don't want to pass along options like -j:
+#
+unexport MAKEFLAGS
+
 #
 # Do a parallel build with multiple jobs, based on the number of CPUs online
 # in this system: 'make -j8' on a 8-CPU system, etc.
@@ -18,14 +30,12 @@ ifeq ($(JOBS),)
   endif
 endif
 
-export JOBS
-
 define print_msg
   @printf '    BUILD: Doing '\''make \033[33m-j'$(JOBS)'\033[m'\'' parallel build\n'
 endef
 
 define make
-  @$(MAKE) -f Makefile.perf --no-print-directory -j$(JOBS) $@
+  @$(MAKE) -f Makefile.perf --no-print-directory -j$(JOBS) O=$(O) $@
 endef
 
 #