+/*
+ * RCU torture reader from timer handler. Dereferences rcu_torture_current,
+ * incrementing the corresponding element of the pipeline array. The
+ * counter in the element should never be greater than 1, otherwise, the
+ * RCU implementation is broken.
+ */
+static void rcu_torture_timer(unsigned long unused)
+{
+ int idx;
+ int completed;
+ static DEFINE_RCU_RANDOM(rand);
+ static DEFINE_SPINLOCK(rand_lock);
+ struct rcu_torture *p;
+ int pipe_count;
+
+ idx = cur_ops->readlock();
+ completed = cur_ops->completed();
+ p = rcu_dereference(rcu_torture_current);
+ if (p == NULL) {
+ /* Leave because rcu_torture_writer is not yet underway */
+ cur_ops->readunlock(idx);
+ return;
+ }
+ if (p->rtort_mbtest == 0)
+ atomic_inc(&n_rcu_torture_mberror);
+ spin_lock(&rand_lock);
+ cur_ops->readdelay(&rand);
+ n_rcu_torture_timers++;
+ spin_unlock(&rand_lock);
+ preempt_disable();
+ pipe_count = p->rtort_pipe_count;
+ if (pipe_count > RCU_TORTURE_PIPE_LEN) {
+ /* Should not happen, but... */
+ pipe_count = RCU_TORTURE_PIPE_LEN;
+ }
+ ++__get_cpu_var(rcu_torture_count)[pipe_count];
+ completed = cur_ops->completed() - completed;
+ if (completed > RCU_TORTURE_PIPE_LEN) {
+ /* Should not happen, but... */
+ completed = RCU_TORTURE_PIPE_LEN;
+ }
+ ++__get_cpu_var(rcu_torture_batch)[completed];
+ preempt_enable();
+ cur_ops->readunlock(idx);
+}
+