1obj-y += update.o sync.o 2obj-$(CONFIG_SRCU) += srcu.o 3obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o 4obj-$(CONFIG_TREE_RCU) += tree.o 5obj-$(CONFIG_PREEMPT_RCU) += tree.o 6obj-$(CONFIG_TREE_RCU_TRACE) += tree_trace.o 7obj-$(CONFIG_TINY_RCU) += tiny.o 8