+int poll_schedule_timeout(struct poll_wqueues *pwq, int state,
+ ktime_t *expires, unsigned long slack)
+{
+ int rc = -EINTR;
+
+ set_current_state(state);
+ if (!pwq->triggered)
+ rc = schedule_hrtimeout_range(expires, slack, HRTIMER_MODE_ABS);
+ __set_current_state(TASK_RUNNING);
+
+ /*
+ * Prepare for the next iteration.
+ *
+ * The following set_mb() serves two purposes. First, it's
+ * the counterpart rmb of the wmb in pollwake() such that data
+ * written before wake up is always visible after wake up.
+ * Second, the full barrier guarantees that triggered clearing
+ * doesn't pass event check of the next iteration. Note that
+ * this problem doesn't exist for the first iteration as
+ * add_wait_queue() has full barrier semantics.
+ */
+ set_mb(pwq->triggered, 0);
+
+ return rc;
+}
+EXPORT_SYMBOL(poll_schedule_timeout);
+