Documentation/vm/Makefile - linux - Git at Google

 # kbuild trick to avoid linker error. Can be omitted if a module is built.
 obj- := dummy.o

 # List of programs to build
 hostprogs-y := slabinfo

 # Tell kbuild to always build the programs
 always := $(hostprogs-y)
	# kbuild trick to avoid linker error. Can be omitted if a module is built.
	obj- := dummy.o

	# List of programs to build
	hostprogs-y := slabinfo

	# Tell kbuild to always build the programs
	always := $(hostprogs-y)