diff options
| -rw-r--r-- | fs/eventpoll.c | 25 |
1 files changed, 16 insertions, 9 deletions
diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 10b81e69db74..935c66c809ba 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -1817,23 +1817,30 @@ fetch_events: } write_unlock_irq(&ep->lock); - if (eavail || res) - break; + if (!eavail && !res) + timed_out = !schedule_hrtimeout_range(to, slack, + HRTIMER_MODE_ABS); - if (!schedule_hrtimeout_range(to, slack, HRTIMER_MODE_ABS)) { - timed_out = 1; - break; - } - - /* We were woken up, thus go and try to harvest some events */ + /* + * We were woken up, thus go and try to harvest some events. + * If timed out and still on the wait queue, recheck eavail + * carefully under lock, below. + */ eavail = 1; - } while (0); __set_current_state(TASK_RUNNING); if (!list_empty_careful(&wait.entry)) { write_lock_irq(&ep->lock); + /* + * If the thread timed out and is not on the wait queue, it + * means that the thread was woken up after its timeout expired + * before it could reacquire the lock. Thus, when wait.entry is + * empty, it needs to harvest events. + */ + if (timed_out) + eavail = list_empty(&wait.entry); __remove_wait_queue(&ep->wq, &wait); write_unlock_irq(&ep->lock); } |