On Mon, Sep 04, 2017 at 02:37:24PM +0200, Peter Zijlstra wrote:

-	 once.o refcount.o usercopy.o errseq.o
-obj-y += string_helpers.o
+	 once.o usercopy.o errseq.o string_helpers.o hexdump.o kstrtox.o
+
+obj-$(CONFIG_REFCOUNT_FULL) += refcount.o
 obj-$(CONFIG_TEST_STRING_HELPERS) += test-string_helpers.o
-obj-y += hexdump.o
 obj-$(CONFIG_TEST_HEXDUMP) += test_hexdump.o
-obj-y += kstrtox.o

File per line so everything is not lumped together even if it is obj-y.