rcu: Clean up flavor-related definitions and comments in tree_plugin.h

#include "../locking/rtmutex_common.h"

/*

 * Control variables for per-CPU and per-rcu_node kthreads.  These

 * handle all flavors of RCU.

 * Control variables for per-CPU and per-rcu_node kthreads.

 */

static DEFINE_PER_CPU(struct task_struct *, rcu_cpu_kthread_task);

DEFINE_PER_CPU(unsigned int, rcu_cpu_kthread_status);

 *

 * Note that this guarantee implies further memory-ordering guarantees.

 * On systems with more than one CPU, when synchronize_rcu() returns,

 * each CPU is guaranteed to have executed a full memory barrier since the

 * end of its last RCU-sched read-side critical section whose beginning

 * each CPU is guaranteed to have executed a full memory barrier since

 * the end of its last RCU read-side critical section whose beginning

 * preceded the call to synchronize_rcu().  In addition, each CPU having

 * an RCU read-side critical section that extends beyond the return from

 * synchronize_rcu() is guaranteed to have executed a full memory barrier

	RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map) ||

			 lock_is_held(&rcu_lock_map) ||

			 lock_is_held(&rcu_sched_lock_map),

			 "Illegal synchronize_rcu() in RCU-sched read-side critical section");

			 "Illegal synchronize_rcu() in RCU read-side critical section");

	if (rcu_blocking_is_gp())

		return;

	if (rcu_gp_is_expedited())

}

/*

 * Per-CPU kernel thread that invokes RCU callbacks.  This replaces the

 * RCU softirq used in flavors and configurations of RCU that do not

 * support RCU priority boosting.

 * Per-CPU kernel thread that invokes RCU callbacks.  This replaces

 * the RCU softirq used in configurations of RCU that do not support RCU

 * priority boosting.

 */

static void rcu_cpu_kthread(unsigned int cpu)

{

 * 1 if so.  This function is part of the RCU implementation; it is -not-

 * an exported member of the RCU API.

 *

 * Because we not have RCU_FAST_NO_HZ, just check whether this CPU needs

 * any flavor of RCU.

 * Because we not have RCU_FAST_NO_HZ, just check whether or not this

 * CPU has RCU callbacks queued.

 */

int rcu_needs_cpu(u64 basemono, u64 *nextevt)

{

module_param(rcu_idle_lazy_gp_delay, int, 0644);

/*

 * Try to advance callbacks for all flavors of RCU on the current CPU, but

 * only if it has been awhile since the last time we did so.  Afterwards,

 * if there are any callbacks ready for immediate invocation, return true.

 * Try to advance callbacks on the current CPU, but only if it has been

 * awhile since the last time we did so.  Afterwards, if there are any

 * callbacks ready for immediate invocation, return true.

 */

static bool __maybe_unused rcu_try_advance_all_cbs(void)

{

	pr_err("\t");

}

/* Zero ->ticks_this_gp for all flavors of RCU. */

/* Zero ->ticks_this_gp and snapshot the number of RCU softirq handlers. */

static void zero_cpu_stall_ticks(struct rcu_data *rdp)

{

	rdp->ticks_this_gp = 0;

}

/*

 * Does the specified CPU need an RCU callback for the specified flavor

 * Does the specified CPU need an RCU callback for this invocation

 * of rcu_barrier()?

 */

static bool rcu_nocb_cpu_needs_barrier(int cpu)

/*

 * If the specified CPU is a no-CBs CPU that does not already have its

 * rcuo kthread for the specified RCU flavor, spawn it.  If the CPUs are

 * brought online out of order, this can require re-organizing the

 * leader-follower relationships.

 * rcuo kthread, spawn it.  If the CPUs are brought online out of order,

 * this can require re-organizing the leader-follower relationships.

 */

static void rcu_spawn_one_nocb_kthread(int cpu)

{

		rdp_spawn->nocb_next_follower = rdp_old_leader;

	}

	/* Spawn the kthread for this CPU and RCU flavor. */

	/* Spawn the kthread for this CPU. */

	t = kthread_run(rcu_nocb_kthread, rdp_spawn,

			"rcuo%c/%d", rcu_state.abbr, cpu);

	BUG_ON(IS_ERR(t));