Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 500 insertions, 0 deletions

diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
new file mode 100644
index 000000000..4e74df768
--- /dev/null
+++ b/kernel/rcu/tree.h
@@ -0,0 +1,500 @@
+/*
+ * Read-Copy Update mechanism for mutual exclusion (tree-based version)
+ * Internal non-public definitions.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
+ *
+ * Copyright IBM Corporation, 2008
+ *
+ * Author: Ingo Molnar <mingo@elte.hu>
+ *	   Paul E. McKenney <paulmck@linux.vnet.ibm.com>
+ */
+
+#include <linux/cache.h>
+#include <linux/spinlock.h>
+#include <linux/rtmutex.h>
+#include <linux/threads.h>
+#include <linux/cpumask.h>
+#include <linux/seqlock.h>
+#include <linux/swait.h>
+#include <linux/stop_machine.h>
+#include <linux/rcu_node_tree.h>
+
+#include "rcu_segcblist.h"
+
+/*
+ * Dynticks per-CPU state.
+ */
+struct rcu_dynticks {
+	long dynticks_nesting;      /* Track process nesting level. */
+	long dynticks_nmi_nesting;  /* Track irq/NMI nesting level. */
+	atomic_t dynticks;	    /* Even value for idle, else odd. */
+	bool rcu_need_heavy_qs;     /* GP old, need heavy quiescent state. */
+	unsigned long rcu_qs_ctr;   /* Light universal quiescent state ctr. */
+	bool rcu_urgent_qs;	    /* GP old need light quiescent state. */
+#ifdef CONFIG_RCU_FAST_NO_HZ
+	bool all_lazy;		    /* Are all CPU's CBs lazy? */
+	unsigned long nonlazy_posted;
+				    /* # times non-lazy CBs posted to CPU. */
+	unsigned long nonlazy_posted_snap;
+				    /* idle-period nonlazy_posted snapshot. */
+	unsigned long last_accelerate;
+				    /* Last jiffy CBs were accelerated. */
+	unsigned long last_advance_all;
+				    /* Last jiffy CBs were all advanced. */
+	int tick_nohz_enabled_snap; /* Previously seen value from sysfs. */
+#endif /* #ifdef CONFIG_RCU_FAST_NO_HZ */
+};
+
+/* Communicate arguments to a workqueue handler. */
+struct rcu_exp_work {
+	smp_call_func_t rew_func;
+	struct rcu_state *rew_rsp;
+	unsigned long rew_s;
+	struct work_struct rew_work;
+};
+
+/* RCU's kthread states for tracing. */
+#define RCU_KTHREAD_STOPPED  0
+#define RCU_KTHREAD_RUNNING  1
+#define RCU_KTHREAD_WAITING  2
+#define RCU_KTHREAD_OFFCPU   3
+#define RCU_KTHREAD_YIELDING 4
+#define RCU_KTHREAD_MAX      4
+
+/*
+ * Definition for node within the RCU grace-period-detection hierarchy.
+ */
+struct rcu_node {
+	raw_spinlock_t __private lock;	/* Root rcu_node's lock protects */
+					/*  some rcu_state fields as well as */
+					/*  following. */
+	unsigned long gp_seq;	/* Track rsp->rcu_gp_seq. */
+	unsigned long gp_seq_needed; /* Track rsp->rcu_gp_seq_needed. */
+	unsigned long completedqs; /* All QSes done for this node. */
+	unsigned long qsmask;	/* CPUs or groups that need to switch in */
+				/*  order for current grace period to proceed.*/
+				/*  In leaf rcu_node, each bit corresponds to */
+				/*  an rcu_data structure, otherwise, each */
+				/*  bit corresponds to a child rcu_node */
+				/*  structure. */
+	unsigned long rcu_gp_init_mask;	/* Mask of offline CPUs at GP init. */
+	unsigned long qsmaskinit;
+				/* Per-GP initial value for qsmask. */
+				/*  Initialized from ->qsmaskinitnext at the */
+				/*  beginning of each grace period. */
+	unsigned long qsmaskinitnext;
+				/* Online CPUs for next grace period. */
+	unsigned long expmask;	/* CPUs or groups that need to check in */
+				/*  to allow the current expedited GP */
+				/*  to complete. */
+	unsigned long expmaskinit;
+				/* Per-GP initial values for expmask. */
+				/*  Initialized from ->expmaskinitnext at the */
+				/*  beginning of each expedited GP. */
+	unsigned long expmaskinitnext;
+				/* Online CPUs for next expedited GP. */
+				/*  Any CPU that has ever been online will */
+				/*  have its bit set. */
+	unsigned long ffmask;	/* Fully functional CPUs. */
+	unsigned long grpmask;	/* Mask to apply to parent qsmask. */
+				/*  Only one bit will be set in this mask. */
+	int	grplo;		/* lowest-numbered CPU or group here. */
+	int	grphi;		/* highest-numbered CPU or group here. */
+	u8	grpnum;		/* CPU/group number for next level up. */
+	u8	level;		/* root is at level 0. */
+	bool	wait_blkd_tasks;/* Necessary to wait for blocked tasks to */
+				/*  exit RCU read-side critical sections */
+				/*  before propagating offline up the */
+				/*  rcu_node tree? */
+	struct rcu_node *parent;
+	struct list_head blkd_tasks;
+				/* Tasks blocked in RCU read-side critical */
+				/*  section.  Tasks are placed at the head */
+				/*  of this list and age towards the tail. */
+	struct list_head *gp_tasks;
+				/* Pointer to the first task blocking the */
+				/*  current grace period, or NULL if there */
+				/*  is no such task. */
+	struct list_head *exp_tasks;
+				/* Pointer to the first task blocking the */
+				/*  current expedited grace period, or NULL */
+				/*  if there is no such task.  If there */
+				/*  is no current expedited grace period, */
+				/*  then there can cannot be any such task. */
+	struct list_head *boost_tasks;
+				/* Pointer to first task that needs to be */
+				/*  priority boosted, or NULL if no priority */
+				/*  boosting is needed for this rcu_node */
+				/*  structure.  If there are no tasks */
+				/*  queued on this rcu_node structure that */
+				/*  are blocking the current grace period, */
+				/*  there can be no such task. */
+	struct rt_mutex boost_mtx;
+				/* Used only for the priority-boosting */
+				/*  side effect, not as a lock. */
+	unsigned long boost_time;
+				/* When to start boosting (jiffies). */
+	struct task_struct *boost_kthread_task;
+				/* kthread that takes care of priority */
+				/*  boosting for this rcu_node structure. */
+	unsigned int boost_kthread_status;
+				/* State of boost_kthread_task for tracing. */
+#ifdef CONFIG_RCU_NOCB_CPU
+	struct swait_queue_head nocb_gp_wq[2];
+				/* Place for rcu_nocb_kthread() to wait GP. */
+#endif /* #ifdef CONFIG_RCU_NOCB_CPU */
+	raw_spinlock_t fqslock ____cacheline_internodealigned_in_smp;
+
+	spinlock_t exp_lock ____cacheline_internodealigned_in_smp;
+	unsigned long exp_seq_rq;
+	wait_queue_head_t exp_wq[4];
+	struct rcu_exp_work rew;
+	bool exp_need_flush;	/* Need to flush workitem? */
+} ____cacheline_internodealigned_in_smp;
+
+/*
+ * Bitmasks in an rcu_node cover the interval [grplo, grphi] of CPU IDs, and
+ * are indexed relative to this interval rather than the global CPU ID space.
+ * This generates the bit for a CPU in node-local masks.
+ */
+#define leaf_node_cpu_bit(rnp, cpu) (1UL << ((cpu) - (rnp)->grplo))
+
+/*
+ * Union to allow "aggregate OR" operation on the need for a quiescent
+ * state by the normal and expedited grace periods.
+ */
+union rcu_noqs {
+	struct {
+		u8 norm;
+		u8 exp;
+	} b; /* Bits. */
+	u16 s; /* Set of bits, aggregate OR here. */
+};
+
+/* Per-CPU data for read-copy update. */
+struct rcu_data {
+	/* 1) quiescent-state and grace-period handling : */
+	unsigned long	gp_seq;		/* Track rsp->rcu_gp_seq counter. */
+	unsigned long	gp_seq_needed;	/* Track rsp->rcu_gp_seq_needed ctr. */
+	unsigned long	rcu_qs_ctr_snap;/* Snapshot of rcu_qs_ctr to check */
+					/*  for rcu_all_qs() invocations. */
+	union rcu_noqs	cpu_no_qs;	/* No QSes yet for this CPU. */
+	bool		core_needs_qs;	/* Core waits for quiesc state. */
+	bool		beenonline;	/* CPU online at least once. */
+	bool		gpwrap;		/* Possible ->gp_seq wrap. */
+	struct rcu_node *mynode;	/* This CPU's leaf of hierarchy */
+	unsigned long grpmask;		/* Mask to apply to leaf qsmask. */
+	unsigned long	ticks_this_gp;	/* The number of scheduling-clock */
+					/*  ticks this CPU has handled */
+					/*  during and after the last grace */
+					/* period it is aware of. */
+
+	/* 2) batch handling */
+	struct rcu_segcblist cblist;	/* Segmented callback list, with */
+					/* different callbacks waiting for */
+					/* different grace periods. */
+	long		qlen_last_fqs_check;
+					/* qlen at last check for QS forcing */
+	unsigned long	n_force_qs_snap;
+					/* did other CPU force QS recently? */
+	long		blimit;		/* Upper limit on a processed batch */
+
+	/* 3) dynticks interface. */
+	struct rcu_dynticks *dynticks;	/* Shared per-CPU dynticks state. */
+	int dynticks_snap;		/* Per-GP tracking for dynticks. */
+
+	/* 4) reasons this CPU needed to be kicked by force_quiescent_state */
+	unsigned long dynticks_fqs;	/* Kicked due to dynticks idle. */
+	unsigned long cond_resched_completed;
+					/* Grace period that needs help */
+					/*  from cond_resched(). */
+
+	/* 5) _rcu_barrier(), OOM callbacks, and expediting. */
+	struct rcu_head barrier_head;
+#ifdef CONFIG_RCU_FAST_NO_HZ
+	struct rcu_head oom_head;
+#endif /* #ifdef CONFIG_RCU_FAST_NO_HZ */
+	int exp_dynticks_snap;		/* Double-check need for IPI. */
+
+	/* 6) Callback offloading. */
+#ifdef CONFIG_RCU_NOCB_CPU
+	struct rcu_head *nocb_head;	/* CBs waiting for kthread. */
+	struct rcu_head **nocb_tail;
+	atomic_long_t nocb_q_count;	/* # CBs waiting for nocb */
+	atomic_long_t nocb_q_count_lazy; /*  invocation (all stages). */
+	struct rcu_head *nocb_follower_head; /* CBs ready to invoke. */
+	struct rcu_head **nocb_follower_tail;
+	struct swait_queue_head nocb_wq; /* For nocb kthreads to sleep on. */
+	struct task_struct *nocb_kthread;
+	raw_spinlock_t nocb_lock;	/* Guard following pair of fields. */
+	int nocb_defer_wakeup;		/* Defer wakeup of nocb_kthread. */
+	struct timer_list nocb_timer;	/* Enforce finite deferral. */
+
+	/* The following fields are used by the leader, hence own cacheline. */
+	struct rcu_head *nocb_gp_head ____cacheline_internodealigned_in_smp;
+					/* CBs waiting for GP. */
+	struct rcu_head **nocb_gp_tail;
+	bool nocb_leader_sleep;		/* Is the nocb leader thread asleep? */
+	struct rcu_data *nocb_next_follower;
+					/* Next follower in wakeup chain. */
+
+	/* The following fields are used by the follower, hence new cachline. */
+	struct rcu_data *nocb_leader ____cacheline_internodealigned_in_smp;
+					/* Leader CPU takes GP-end wakeups. */
+#endif /* #ifdef CONFIG_RCU_NOCB_CPU */
+
+	/* 7) Diagnostic data, including RCU CPU stall warnings. */
+	unsigned int softirq_snap;	/* Snapshot of softirq activity. */
+	/* ->rcu_iw* fields protected by leaf rcu_node ->lock. */
+	struct irq_work rcu_iw;		/* Check for non-irq activity. */
+	bool rcu_iw_pending;		/* Is ->rcu_iw pending? */
+	unsigned long rcu_iw_gp_seq;	/* ->gp_seq associated with ->rcu_iw. */
+	unsigned long rcu_ofl_gp_seq;	/* ->gp_seq at last offline. */
+	short rcu_ofl_gp_flags;		/* ->gp_flags at last offline. */
+	unsigned long rcu_onl_gp_seq;	/* ->gp_seq at last online. */
+	short rcu_onl_gp_flags;		/* ->gp_flags at last online. */
+
+	int cpu;
+	struct rcu_state *rsp;
+};
+
+/* Values for nocb_defer_wakeup field in struct rcu_data. */
+#define RCU_NOCB_WAKE_NOT	0
+#define RCU_NOCB_WAKE		1
+#define RCU_NOCB_WAKE_FORCE	2
+
+#define RCU_JIFFIES_TILL_FORCE_QS (1 + (HZ > 250) + (HZ > 500))
+					/* For jiffies_till_first_fqs and */
+					/*  and jiffies_till_next_fqs. */
+
+#define RCU_JIFFIES_FQS_DIV	256	/* Very large systems need more */
+					/*  delay between bouts of */
+					/*  quiescent-state forcing. */
+
+#define RCU_STALL_RAT_DELAY	2	/* Allow other CPUs time to take */
+					/*  at least one scheduling clock */
+					/*  irq before ratting on them. */
+
+#define rcu_wait(cond)							\
+do {									\
+	for (;;) {							\
+		set_current_state(TASK_INTERRUPTIBLE);			\
+		if (cond)						\
+			break;						\
+		schedule();						\
+	}								\
+	__set_current_state(TASK_RUNNING);				\
+} while (0)
+
+/*
+ * RCU global state, including node hierarchy.  This hierarchy is
+ * represented in "heap" form in a dense array.  The root (first level)
+ * of the hierarchy is in ->node[0] (referenced by ->level[0]), the second
+ * level in ->node[1] through ->node[m] (->node[1] referenced by ->level[1]),
+ * and the third level in ->node[m+1] and following (->node[m+1] referenced
+ * by ->level[2]).  The number of levels is determined by the number of
+ * CPUs and by CONFIG_RCU_FANOUT.  Small systems will have a "hierarchy"
+ * consisting of a single rcu_node.
+ */
+struct rcu_state {
+	struct rcu_node node[NUM_RCU_NODES];	/* Hierarchy. */
+	struct rcu_node *level[RCU_NUM_LVLS + 1];
+						/* Hierarchy levels (+1 to */
+						/*  shut bogus gcc warning) */
+	struct rcu_data __percpu *rda;		/* pointer of percu rcu_data. */
+	call_rcu_func_t call;			/* call_rcu() flavor. */
+	int ncpus;				/* # CPUs seen so far. */
+
+	/* The following fields are guarded by the root rcu_node's lock. */
+
+	u8	boost ____cacheline_internodealigned_in_smp;
+						/* Subject to priority boost. */
+	unsigned long gp_seq;			/* Grace-period sequence #. */
+	struct task_struct *gp_kthread;		/* Task for grace periods. */
+	struct swait_queue_head gp_wq;		/* Where GP task waits. */
+	short gp_flags;				/* Commands for GP task. */
+	short gp_state;				/* GP kthread sleep state. */
+
+	/* End of fields guarded by root rcu_node's lock. */
+
+	struct mutex barrier_mutex;		/* Guards barrier fields. */
+	atomic_t barrier_cpu_count;		/* # CPUs waiting on. */
+	struct completion barrier_completion;	/* Wake at barrier end. */
+	unsigned long barrier_sequence;		/* ++ at start and end of */
+						/*  _rcu_barrier(). */
+	/* End of fields guarded by barrier_mutex. */
+
+	struct mutex exp_mutex;			/* Serialize expedited GP. */
+	struct mutex exp_wake_mutex;		/* Serialize wakeup. */
+	unsigned long expedited_sequence;	/* Take a ticket. */
+	atomic_t expedited_need_qs;		/* # CPUs left to check in. */
+	struct swait_queue_head expedited_wq;	/* Wait for check-ins. */
+	int ncpus_snap;				/* # CPUs seen last time. */
+
+	unsigned long jiffies_force_qs;		/* Time at which to invoke */
+						/*  force_quiescent_state(). */
+	unsigned long jiffies_kick_kthreads;	/* Time at which to kick */
+						/*  kthreads, if configured. */
+	unsigned long n_force_qs;		/* Number of calls to */
+						/*  force_quiescent_state(). */
+	unsigned long gp_start;			/* Time at which GP started, */
+						/*  but in jiffies. */
+	unsigned long gp_activity;		/* Time of last GP kthread */
+						/*  activity in jiffies. */
+	unsigned long gp_req_activity;		/* Time of last GP request */
+						/*  in jiffies. */
+	unsigned long jiffies_stall;		/* Time at which to check */
+						/*  for CPU stalls. */
+	unsigned long jiffies_resched;		/* Time at which to resched */
+						/*  a reluctant CPU. */
+	unsigned long n_force_qs_gpstart;	/* Snapshot of n_force_qs at */
+						/*  GP start. */
+	unsigned long gp_max;			/* Maximum GP duration in */
+						/*  jiffies. */
+	const char *name;			/* Name of structure. */
+	char abbr;				/* Abbreviated name. */
+	struct list_head flavors;		/* List of RCU flavors. */
+
+	spinlock_t ofl_lock ____cacheline_internodealigned_in_smp;
+						/* Synchronize offline with */
+						/*  GP pre-initialization. */
+};
+
+/* Values for rcu_state structure's gp_flags field. */
+#define RCU_GP_FLAG_INIT 0x1	/* Need grace-period initialization. */
+#define RCU_GP_FLAG_FQS  0x2	/* Need grace-period quiescent-state forcing. */
+
+/* Values for rcu_state structure's gp_state field. */
+#define RCU_GP_IDLE	 0	/* Initial state and no GP in progress. */
+#define RCU_GP_WAIT_GPS  1	/* Wait for grace-period start. */
+#define RCU_GP_DONE_GPS  2	/* Wait done for grace-period start. */
+#define RCU_GP_ONOFF     3	/* Grace-period initialization hotplug. */
+#define RCU_GP_INIT      4	/* Grace-period initialization. */
+#define RCU_GP_WAIT_FQS  5	/* Wait for force-quiescent-state time. */
+#define RCU_GP_DOING_FQS 6	/* Wait done for force-quiescent-state time. */
+#define RCU_GP_CLEANUP   7	/* Grace-period cleanup started. */
+#define RCU_GP_CLEANED   8	/* Grace-period cleanup complete. */
+
+#ifndef RCU_TREE_NONCORE
+static const char * const gp_state_names[] = {
+	"RCU_GP_IDLE",
+	"RCU_GP_WAIT_GPS",
+	"RCU_GP_DONE_GPS",
+	"RCU_GP_ONOFF",
+	"RCU_GP_INIT",
+	"RCU_GP_WAIT_FQS",
+	"RCU_GP_DOING_FQS",
+	"RCU_GP_CLEANUP",
+	"RCU_GP_CLEANED",
+};
+#endif /* #ifndef RCU_TREE_NONCORE */
+
+extern struct list_head rcu_struct_flavors;
+
+/* Sequence through rcu_state structures for each RCU flavor. */
+#define for_each_rcu_flavor(rsp) \
+	list_for_each_entry((rsp), &rcu_struct_flavors, flavors)
+
+/*
+ * RCU implementation internal declarations:
+ */
+extern struct rcu_state rcu_sched_state;
+
+extern struct rcu_state rcu_bh_state;
+
+#ifdef CONFIG_PREEMPT_RCU
+extern struct rcu_state rcu_preempt_state;
+#endif /* #ifdef CONFIG_PREEMPT_RCU */
+
+int rcu_dynticks_snap(struct rcu_dynticks *rdtp);
+
+#ifdef CONFIG_RCU_BOOST
+DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_status);
+DECLARE_PER_CPU(int, rcu_cpu_kthread_cpu);
+DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_loops);
+DECLARE_PER_CPU(char, rcu_cpu_has_work);
+#endif /* #ifdef CONFIG_RCU_BOOST */
+
+#ifndef RCU_TREE_NONCORE
+
+/* Forward declarations for rcutree_plugin.h */
+static void rcu_bootup_announce(void);
+static void rcu_preempt_note_context_switch(bool preempt);
+static int rcu_preempt_blocked_readers_cgp(struct rcu_node *rnp);
+#ifdef CONFIG_HOTPLUG_CPU
+static bool rcu_preempt_has_tasks(struct rcu_node *rnp);
+#endif /* #ifdef CONFIG_HOTPLUG_CPU */
+static void rcu_print_detail_task_stall(struct rcu_state *rsp);
+static int rcu_print_task_stall(struct rcu_node *rnp);
+static int rcu_print_task_exp_stall(struct rcu_node *rnp);
+static void rcu_preempt_check_blocked_tasks(struct rcu_state *rsp,
+					    struct rcu_node *rnp);
+static void rcu_preempt_check_callbacks(void);
+void call_rcu(struct rcu_head *head, rcu_callback_t func);
+static void __init __rcu_init_preempt(void);
+static void dump_blkd_tasks(struct rcu_state *rsp, struct rcu_node *rnp,
+			    int ncheck);
+static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags);
+static void rcu_preempt_boost_start_gp(struct rcu_node *rnp);
+static void invoke_rcu_callbacks_kthread(void);
+static bool rcu_is_callbacks_kthread(void);
+#ifdef CONFIG_RCU_BOOST
+static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
+						 struct rcu_node *rnp);
+#endif /* #ifdef CONFIG_RCU_BOOST */
+static void __init rcu_spawn_boost_kthreads(void);
+static void rcu_prepare_kthreads(int cpu);
+static void rcu_cleanup_after_idle(void);
+static void rcu_prepare_for_idle(void);
+static void rcu_idle_count_callbacks_posted(void);
+static bool rcu_preempt_has_tasks(struct rcu_node *rnp);
+static void print_cpu_stall_info_begin(void);
+static void print_cpu_stall_info(struct rcu_state *rsp, int cpu);
+static void print_cpu_stall_info_end(void);
+static void zero_cpu_stall_ticks(struct rcu_data *rdp);
+static void increment_cpu_stall_ticks(void);
+static bool rcu_nocb_cpu_needs_barrier(struct rcu_state *rsp, int cpu);
+static struct swait_queue_head *rcu_nocb_gp_get(struct rcu_node *rnp);
+static void rcu_nocb_gp_cleanup(struct swait_queue_head *sq);
+static void rcu_init_one_nocb(struct rcu_node *rnp);
+static bool __call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *rhp,
+			    bool lazy, unsigned long flags);
+static bool rcu_nocb_adopt_orphan_cbs(struct rcu_data *my_rdp,
+				      struct rcu_data *rdp,
+				      unsigned long flags);
+static int rcu_nocb_need_deferred_wakeup(struct rcu_data *rdp);
+static void do_nocb_deferred_wakeup(struct rcu_data *rdp);
+static void rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp);
+static void rcu_spawn_all_nocb_kthreads(int cpu);
+static void __init rcu_spawn_nocb_kthreads(void);
+#ifdef CONFIG_RCU_NOCB_CPU
+static void __init rcu_organize_nocb_kthreads(struct rcu_state *rsp);
+#endif /* #ifdef CONFIG_RCU_NOCB_CPU */
+static bool init_nocb_callback_list(struct rcu_data *rdp);
+static void rcu_bind_gp_kthread(void);
+static bool rcu_nohz_full_cpu(struct rcu_state *rsp);
+static void rcu_dynticks_task_enter(void);
+static void rcu_dynticks_task_exit(void);
+
+#ifdef CONFIG_SRCU
+void srcu_online_cpu(unsigned int cpu);
+void srcu_offline_cpu(unsigned int cpu);
+#else /* #ifdef CONFIG_SRCU */
+void srcu_online_cpu(unsigned int cpu) { }
+void srcu_offline_cpu(unsigned int cpu) { }
+#endif /* #else #ifdef CONFIG_SRCU */
+
+#endif /* #ifndef RCU_TREE_NONCORE */