kernel/rcu/tree.h

328 struct rcu_state {  struct
329 	struct rcu_node node[NUM_RCU_NODES];	/* Hierarchy. */
330 	struct rcu_node *level[RCU_NUM_LVLS + 1];
333 	int ncpus;				/* # CPUs seen so far. */
334 	int n_online_cpus;			/* # CPUs online for RCU. */
338 	unsigned long gp_seq ____cacheline_internodealigned_in_smp;
340 	unsigned long gp_max;			/* Maximum GP duration in */
342 	struct task_struct *gp_kthread;		/* Task for grace periods. */
343 	struct swait_queue_head gp_wq;		/* Where GP task waits. */
344 	short gp_flags;				/* Commands for GP task. */
345 	short gp_state;				/* GP kthread sleep state. */
346 	unsigned long gp_wake_time;		/* Last GP kthread wake. */
347 	unsigned long gp_wake_seq;		/* ->gp_seq at ^^^. */
348 	unsigned long gp_seq_polled;		/* GP seq for polled API. */
349 	unsigned long gp_seq_polled_snap;	/* ->gp_seq_polled at normal GP start. */
350 	unsigned long gp_seq_polled_exp_snap;	/* ->gp_seq_polled at expedited GP start. */
354 	struct mutex barrier_mutex;		/* Guards barrier fields. */
355 	atomic_t barrier_cpu_count;		/* # CPUs waiting on. */
356 	struct completion barrier_completion;	/* Wake at barrier end. */
357 	unsigned long barrier_sequence;		/* ++ at start and end of */
361 	raw_spinlock_t barrier_lock;		/* Protects ->barrier_seq_snap. */
363 	struct mutex exp_mutex;			/* Serialize expedited GP. */
364 	struct mutex exp_wake_mutex;		/* Serialize wakeup. */
365 	unsigned long expedited_sequence;	/* Take a ticket. */
366 	atomic_t expedited_need_qs;		/* # CPUs left to check in. */
367 	struct swait_queue_head expedited_wq;	/* Wait for check-ins. */
368 	int ncpus_snap;				/* # CPUs seen last time. */
369 	u8 cbovld;				/* Callback overload now? */
370 	u8 cbovldnext;				/* ^        ^  next time? */
372 	unsigned long jiffies_force_qs;		/* Time at which to invoke */
374 	unsigned long jiffies_kick_kthreads;	/* Time at which to kick */
376 	unsigned long n_force_qs;		/* Number of calls to */
378 	unsigned long gp_start;			/* Time at which GP started, */
380 	unsigned long gp_end;			/* Time last GP ended, again */
405 /* Values for rcu_state structure's gp_flags field. */  argument