178 struct rcu_data {  struct
180 	unsigned long	gp_seq;		/* Track rsp->gp_seq counter. */
181 	unsigned long	gp_seq_needed;	/* Track furthest future GP request. */
182 	union rcu_noqs	cpu_no_qs;	/* No QSes yet for this CPU. */
183 	bool		core_needs_qs;	/* Core waits for quiescent state. */
184 	bool		beenonline;	/* CPU online at least once. */
185 	bool		gpwrap;		/* Possible ->gp_seq wrap. */
186 	bool		cpu_started;	/* RCU watching this onlining CPU. */
187 	struct rcu_node *mynode;	/* This CPU's leaf of hierarchy */
188 	unsigned long grpmask;		/* Mask to apply to leaf qsmask. */
189 	unsigned long	ticks_this_gp;	/* The number of scheduling-clock */
193 	struct irq_work defer_qs_iw;	/* Obtain later scheduler attention. */
194 	bool defer_qs_iw_pending;	/* Scheduler attention pending? */
195 	struct work_struct strict_work;	/* Schedule readers for strict GPs. */
198 	struct rcu_segcblist cblist;	/* Segmented callback list, with */
201 	long		qlen_last_fqs_check;
203 	unsigned long	n_cbs_invoked;	/* # callbacks invoked since boot. */
204 	unsigned long	n_force_qs_snap;
206 	long		blimit;		/* Upper limit on a processed batch */
209 	int  watching_snap;		/* Per-GP tracking for dynticks. */
210 	bool rcu_need_heavy_qs;		/* GP old, so heavy quiescent state! */
211 	bool rcu_urgent_qs;		/* GP old need light quiescent state. */
212 	bool rcu_forced_tick;		/* Forced tick to provide QS. */
213 	bool rcu_forced_tick_exp;	/*   ... provide QS to expedited GP. */
216 	unsigned long barrier_seq_snap;	/* Snap of rcu_state.barrier_sequence. */
217 	struct rcu_head barrier_head;
218 	int exp_watching_snap;		/* Double-check need for IPI. */
222 	struct swait_queue_head nocb_cb_wq; /* For nocb kthreads to sleep on. */
223 	struct swait_queue_head nocb_state_wq; /* For offloading state changes */
224 	struct task_struct *nocb_gp_kthread;
225 	raw_spinlock_t nocb_lock;	/* Guard following pair of fields. */
226 	int nocb_defer_wakeup;		/* Defer wakeup of nocb_kthread. */
250 					 * Head of rcu_data list in wakeup chain,  argument
253 	struct list_head nocb_entry_rdp; /* rcu_data node in wakeup chain. */  argument
254 	struct rcu_data *nocb_toggling_rdp; /* rdp queued for (de-)offloading */  argument
257 	struct rcu_data *nocb_gp_rdp ____cacheline_internodealigned_in_smp;  argument
262 	struct task_struct *rcu_cpu_kthread_task;
287 /* Values for nocb_defer_wakeup field in struct rcu_data. */  argument