Messages in this thread Patch in this message |  | | From | "Jay Vosburgh" <> | | Date | Thu, 7 Nov 2002 15:53:06 -0700 | | Subject | [PATCH] 2.5.46: epoll ep_insert doesn't wake waiters if events exist |
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The logic in fs/eventpoll.c:ep_insert() checks to see if events are already present when processing an EP_CTL_ADD operation, and, if any are, adds them to the list. It does not wake up any waiters, so, e.g., another thread waiting in epoll_wait() will not be awakened for these events. The fix is to have ep_insert() do wakeups, just as ep_poll_callback() does when it adds events.
-J
diff -ur linux-2.5.46.orig/fs/eventpoll.c linux-2.5.46/fs/eventpoll.c --- linux-2.5.46.orig/fs/eventpoll.c Thu Nov 7 14:31:21 2002 +++ linux-2.5.46/fs/eventpoll.c Thu Nov 7 14:32:16 2002 @@ -838,8 +838,13 @@ list_add(&dpi->llink, ep_hash_entry(ep, ep_hash_index(ep, tfile)));
/* If the file is already "ready" we drop it inside the ready list */ - if ((revents & pfd->events) && !EP_IS_LINKED(&dpi->rdllink)) + if ((revents & pfd->events) && !EP_IS_LINKED(&dpi->rdllink)) { list_add(&dpi->rdllink, &ep->rdllist); + if (waitqueue_active(&ep->wq)) + wake_up(&ep->wq); + if (waitqueue_active(&ep->poll_wait)) + wake_up(&ep->poll_wait); + }
write_unlock_irqrestore(&ep->lock, flags);
(See attached file: epoll-2.5.46-insert.patch) [unhandled content-type:application/octet-stream]
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