Re: when and where does ep_poll_callback be called ?

[horseriver <horserivers@gmail.com>]

On Mon, Jan 14, 2013 at 08:35:29AM -0800, Randy Dunlap wrote:
> On 01/13/13 17:11, horseriver wrote:
> > hi:
> > 
> > 
> >    I'm studying the epoll module , I can not find ep_poll_callback be called somewhere .
> 
> 
> It's right there in fs/eventpoll.c:
> 
> 
> /*
>  * This is the callback that is used to add our wait queue to the
>  * target file wakeup lists.
>  */
> static void ep_ptable_queue_proc(struct file *file, wait_queue_head_t *whead,
> 				 poll_table *pt)
> {
> 	struct epitem *epi = ep_item_from_epqueue(pt);
> 	struct eppoll_entry *pwq;
> 
> 	if (epi->nwait >= 0 && (pwq = kmem_cache_alloc(pwq_cache, GFP_KERNEL))) {
> >>>>>		init_waitqueue_func_entry(&pwq->wait, ep_poll_callback);

     Thanks!
     
     I know this is setting  the callbak function into watqueue . But not the called place . 

     I want to know the code which calls  ep_poll_callback .

     Perhaps , it is called at tcp layer when a datagram is reached . but I have not find that key  code .

     

> 		pwq->whead = whead;
> 		pwq->base = epi;
> 		add_wait_queue(whead, &pwq->wait);
> 		list_add_tail(&pwq->llink, &epi->pwqlist);
> 		epi->nwait++;
> 
> 
> 
> -- 
> ~Randy