From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: when and where does ep_poll_callback be called ?
Date: Wed, 13 Mar 2013 06:00:52 +0100
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To: horseriver <horserivers@gmail.com>
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On Mon, 2013-01-14 at 09:11 +0800, horseriver wrote:
> hi:
> 
> 
>    I'm studying the epoll module , I can not find ep_poll_callback be called somewhere .
>    
>   

Thats more a lkml question.

But you can figure it yourself :

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 9fec183..c6e7490 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -928,6 +928,7 @@ static int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync, void *k
 	struct epitem *epi = ep_item_from_wait(wait);
 	struct eventpoll *ep = epi->ep;
 
+	WARN_ON_ONCE(1);
 	if ((unsigned long)key & POLLFREE) {
 		ep_pwq_from_wait(wait)->whead = NULL;
 		/*