- call_rcu(head, rcu_barrier_callback);
-}
-
-/**
- * rcu_barrier - Wait until all the in-flight RCUs are complete.
- */
-void rcu_barrier(void)
-{
- BUG_ON(in_interrupt());
- /* Take cpucontrol semaphore to protect against CPU hotplug */
- down(&rcu_barrier_sema);
- init_completion(&rcu_barrier_completion);
- atomic_set(&rcu_barrier_cpu_count, 0);
- on_each_cpu(rcu_barrier_func, NULL, 0, 1);
- wait_for_completion(&rcu_barrier_completion);
- up(&rcu_barrier_sema);
-}
-EXPORT_SYMBOL_GPL(rcu_barrier);
-
-/*
- * Invoke the completed RCU callbacks. They are expected to be in
- * a per-cpu list.
- */
-static void rcu_do_batch(struct rcu_data *rdp)
-{
- struct rcu_head *next, *list;
- int count = 0;
-
- list = rdp->donelist;
- while (list) {
- next = rdp->donelist = list->next;
- list->func(list);
- list = next;
- rdp->count--;
- if (++count >= maxbatch)
- break;
- }
- if (!rdp->donelist)
- rdp->donetail = &rdp->donelist;
- else
- tasklet_schedule(&per_cpu(rcu_tasklet, rdp->cpu));
-}
-
-/*
- * Grace period handling:
- * The grace period handling consists out of two steps:
- * - A new grace period is started.
- * This is done by rcu_start_batch. The start is not broadcasted to
- * all cpus, they must pick this up by comparing rcp->cur with
- * rdp->quiescbatch. All cpus are recorded in the
- * rcu_state.cpumask bitmap.
- * - All cpus must go through a quiescent state.
- * Since the start of the grace period is not broadcasted, at least two
- * calls to rcu_check_quiescent_state are required:
- * The first call just notices that a new grace period is running. The
- * following calls check if there was a quiescent state since the beginning
- * of the grace period. If so, it updates rcu_state.cpumask. If
- * the bitmap is empty, then the grace period is completed.
- * rcu_check_quiescent_state calls rcu_start_batch(0) to start the next grace
- * period (if necessary).
- */
-/*
- * Register a new batch of callbacks, and start it up if there is currently no
- * active batch and the batch to be registered has not already occurred.
- * Caller must hold rcu_state.lock.
- */
-static void rcu_start_batch(struct rcu_ctrlblk *rcp, struct rcu_state *rsp,
- int next_pending)
-{
- if (next_pending)
- rcp->next_pending = 1;
-
- if (rcp->next_pending &&
- rcp->completed == rcp->cur) {
- rcp->next_pending = 0;
- /*
- * next_pending == 0 must be visible in
- * __rcu_process_callbacks() before it can see new value of cur.
- */
- smp_wmb();
- rcp->cur++;
-
- /*
- * Accessing nohz_cpu_mask before incrementing rcp->cur needs a
- * Barrier Otherwise it can cause tickless idle CPUs to be
- * included in rsp->cpumask, which will extend graceperiods
- * unnecessarily.
- */
- smp_mb();
- cpus_andnot(rsp->cpumask, cpu_online_map, nohz_cpu_mask);
-
- }
-}
-
-/*
- * cpu went through a quiescent state since the beginning of the grace period.
- * Clear it from the cpu mask and complete the grace period if it was the last
- * cpu. Start another grace period if someone has further entries pending
- */
-static void cpu_quiet(int cpu, struct rcu_ctrlblk *rcp, struct rcu_state *rsp)
-{
- cpu_clear(cpu, rsp->cpumask);
- if (cpus_empty(rsp->cpumask)) {
- /* batch completed ! */
- rcp->completed = rcp->cur;
- rcu_start_batch(rcp, rsp, 0);