diff --git a/tools/testing/radix-tree/.gitignore b/tools/testing/radix-tree/.gitignore
index 26dedaf57aabe6c727a7da4c307210c0c3c642ff..d4706c0ffcebdead866851aa98fcb9323e394fe5 100644
--- a/tools/testing/radix-tree/.gitignore
+++ b/tools/testing/radix-tree/.gitignore
@@ -1,3 +1,4 @@
+generated/map-shift.h
 idr.c
 idr-test
 main
diff --git a/tools/testing/radix-tree/Makefile b/tools/testing/radix-tree/Makefile
index ecea846e766016105e6a9e9cc4d02e18358e1d57..f11315bedefc3d68152bef22da0f8ab60f8c5be6 100644
--- a/tools/testing/radix-tree/Makefile
+++ b/tools/testing/radix-tree/Makefile
@@ -6,11 +6,11 @@ CORE_OFILES := radix-tree.o idr.o linux.o test.o find_bit.o
 OFILES = main.o $(CORE_OFILES) regression1.o regression2.o regression3.o \
 	 tag_check.o multiorder.o idr-test.o iteration_check.o benchmark.o
 
-ifdef BENCHMARK
-	CFLAGS += -DBENCHMARK=1
+ifndef SHIFT
+	SHIFT=3
 endif
 
-targets: $(TARGETS)
+targets: mapshift $(TARGETS)
 
 main:	$(OFILES)
 	$(CC) $(CFLAGS) $(LDFLAGS) $^ -o main
@@ -22,11 +22,11 @@ multiorder: multiorder.o $(CORE_OFILES)
 	$(CC) $(CFLAGS) $(LDFLAGS) $^ -o multiorder
 
 clean:
-	$(RM) $(TARGETS) *.o radix-tree.c idr.c
+	$(RM) $(TARGETS) *.o radix-tree.c idr.c generated/map-shift.h
 
 vpath %.c ../../lib
 
-$(OFILES): *.h */*.h \
+$(OFILES): *.h */*.h generated/map-shift.h \
 	../../include/linux/*.h \
 	../../include/asm/*.h \
 	../../../include/linux/radix-tree.h \
@@ -37,3 +37,11 @@ radix-tree.c: ../../../lib/radix-tree.c
 
 idr.c: ../../../lib/idr.c
 	sed -e 's/^static //' -e 's/__always_inline //' -e 's/inline //' < $< > $@
+
+.PHONY: mapshift
+
+mapshift:
+	@if ! grep -qw $(SHIFT) generated/map-shift.h; then		\
+		echo "#define RADIX_TREE_MAP_SHIFT $(SHIFT)" >		\
+				generated/map-shift.h;			\
+	fi
diff --git a/tools/testing/radix-tree/linux/kernel.h b/tools/testing/radix-tree/linux/kernel.h
index 677b8c0f60f97ea2d75d540597975eb855084349..b21a77fddcf7357cf4b9cffc7f1746e0e2053d05 100644
--- a/tools/testing/radix-tree/linux/kernel.h
+++ b/tools/testing/radix-tree/linux/kernel.h
@@ -12,12 +12,6 @@
 #include <linux/log2.h>
 #include "../../../include/linux/kconfig.h"
 
-#ifdef BENCHMARK
-#define RADIX_TREE_MAP_SHIFT	6
-#else
-#define RADIX_TREE_MAP_SHIFT	3
-#endif
-
 #define printk printf
 #define pr_debug printk
 #define pr_cont printk
diff --git a/tools/testing/radix-tree/linux/radix-tree.h b/tools/testing/radix-tree/linux/radix-tree.h
index ddd135fa3af70d66228a05110babbe3c60b4e8be..bf1bb231f9b5cd98a4c0451eaf1eb8744ee89cf5 100644
--- a/tools/testing/radix-tree/linux/radix-tree.h
+++ b/tools/testing/radix-tree/linux/radix-tree.h
@@ -1,5 +1,7 @@
 #ifndef _TEST_RADIX_TREE_H
 #define _TEST_RADIX_TREE_H
+
+#include "generated/map-shift.h"
 #include "../../../../include/linux/radix-tree.h"
 
 extern int kmalloc_verbose;