X-Git-Url: http://git.monstr.eu/?a=blobdiff_plain;f=fs%2Feventpoll.c;h=63a7a6e13dfcd02507682537d30159ece6483aaf;hb=e8c85328b1e88f4ee7f84a1fdbff2f2c7965e026;hp=d8eef21575871560f42a9eefa19951f58c220751;hpb=e411596d48b5b77632deb91afcbc3185b9b658cb;p=linux-2.6-microblaze.git

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index d8eef2157587..63a7a6e13dfc 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -389,19 +389,24 @@ static bool ep_busy_loop_end(void *p, unsigned long start_time)
  *
  * we must do our busy polling with irqs enabled
  */
-static void ep_busy_loop(struct eventpoll *ep, int nonblock)
+static bool ep_busy_loop(struct eventpoll *ep, int nonblock)
 {
 	unsigned int napi_id = READ_ONCE(ep->napi_id);
 
-	if ((napi_id >= MIN_NAPI_ID) && net_busy_loop_on())
+	if ((napi_id >= MIN_NAPI_ID) && net_busy_loop_on()) {
 		napi_busy_loop(napi_id, nonblock ? NULL : ep_busy_loop_end, ep, false,
 			       BUSY_POLL_BUDGET);
-}
-
-static inline void ep_reset_busy_poll_napi_id(struct eventpoll *ep)
-{
-	if (ep->napi_id)
+		if (ep_events_available(ep))
+			return true;
+		/*
+		 * Busy poll timed out.  Drop NAPI ID for now, we can add
+		 * it back in when we have moved a socket with a valid NAPI
+		 * ID onto the ready list.
+		 */
 		ep->napi_id = 0;
+		return false;
+	}
+	return false;
 }
 
 /*
@@ -441,12 +446,9 @@ static inline void ep_set_busy_poll_napi_id(struct epitem *epi)
 
 #else
 
-static inline void ep_busy_loop(struct eventpoll *ep, int nonblock)
-{
-}
-
-static inline void ep_reset_busy_poll_napi_id(struct eventpoll *ep)
+static inline bool ep_busy_loop(struct eventpoll *ep, int nonblock)
 {
+	return false;
 }
 
 static inline void ep_set_busy_poll_napi_id(struct epitem *epi)
@@ -1772,22 +1774,14 @@ static int ep_poll(struct eventpoll *ep, struct epoll_event __user *events,
 	}
 
 fetch_events:
+	do {
+		eavail = ep_events_available(ep);
+		if (!eavail)
+			eavail = ep_busy_loop(ep, timed_out);
 
-	if (!ep_events_available(ep))
-		ep_busy_loop(ep, timed_out);
-
-	eavail = ep_events_available(ep);
-	if (eavail)
-		goto send_events;
-
-	/*
-	 * Busy poll timed out.  Drop NAPI ID for now, we can add
-	 * it back in when we have moved a socket with a valid NAPI
-	 * ID onto the ready list.
-	 */
-	ep_reset_busy_poll_napi_id(ep);
+		if (eavail)
+			goto send_events;
 
-	do {
 		if (signal_pending(current))
 			return -EINTR;
 
@@ -1836,21 +1830,22 @@ fetch_events:
 		 * carefully under lock, below.
 		 */
 		eavail = 1;
-	} while (0);
 
-	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);
-	}
+		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);
+		}
+	} while (0);
 
 send_events:
 	/*