On Wed, 14 Nov 2018, Andrew Morton wrote:
Why was this moved to before the ep_reset_busy_poll_napi_id() call?
That movement placed the code ahead of the block comment which serves
to explain its function.
Yikes, that was a brain fart.
This? Which also fixes that comment and reflows it to use 80 cols.
Looks good, thanks.
--- a/fs/eventpoll.c~fs-epoll-deal-with-wait_queue-only-once-fix
+++ a/fs/eventpoll.c
@@ -1787,15 +1787,6 @@ fetch_events:
if (eavail)
goto send_events;
- if (!waiter) {
- waiter = true;
- init_waitqueue_entry(&wait, current);
-
- spin_lock_irq(&ep->wq.lock);
- __add_wait_queue_exclusive(&ep->wq, &wait);
- spin_unlock_irq(&ep->wq.lock);
- }
-
/*
* 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
@@ -1804,10 +1795,18 @@ fetch_events:
ep_reset_busy_poll_napi_id(ep);
/*
- * We don't have any available event to return to the caller.
- * We need to sleep here, and we will be wake up by
- * ep_poll_callback() when events will become available.
+ * We don't have any available event to return to the caller. We need
+ * to sleep here, and we will be woken by ep_poll_callback() when events
+ * become available.
*/
+ if (!waiter) {
+ waiter = true;
+ init_waitqueue_entry(&wait, current);
+
+ spin_lock_irq(&ep->wq.lock);
+ __add_wait_queue_exclusive(&ep->wq, &wait);
+ spin_unlock_irq(&ep->wq.lock);
+ }
for (;;) {
/*
_
