[PATCH 6/6] fs/epoll: avoid barrier after an epoll_wait(2) timeout

[Davidlohr Bueso]

Upon timeout, we can just exit out of the loop, without
the cost of the changing the task's state smp_store_mb
call. Just exit out of the loop and be done - setting
the task state afterwards will be, of course, redundant.

Signed-off-by: Davidlohr Bueso <d...@stgolabs.net>
---
 fs/eventpoll.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index f6c023f085f6..ec14e5bcdaa9 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -1820,15 +1820,18 @@ static int ep_poll(struct eventpoll *ep, struct 
epoll_event __user *events,
                        res = -EINTR;
                        break;
                }
-               if (ep_events_available(ep) || timed_out)
+               
+               if (ep_events_available(ep))
                        break;
                if (signal_pending(current)) {
                        res = -EINTR;
                        break;
                }
 
-               if (!schedule_hrtimeout_range(to, slack, HRTIMER_MODE_ABS))
+               if (!schedule_hrtimeout_range(to, slack, HRTIMER_MODE_ABS)) {
                        timed_out = 1;
+                       break;
+               }
        }
 
        __set_current_state(TASK_RUNNING);
-- 
2.16.4