RCU_GP_WAIT_FQS
WRITE_ONCE(rcu_state.gp_state, RCU_GP_WAIT_FQS);
[RCU_GP_WAIT_FQS] = "RCU_GP_WAIT_FQS",
if (gp_state == RCU_GP_WAIT_FQS &&
gp_state_getname(RCU_GP_WAIT_FQS), RCU_GP_WAIT_FQS,