epoll: optimize setting task running after blocking
After waking up a task waiting for an event, we explicitly mark it as
TASK_RUNNING (which is necessary as we do the checks for wakeups as
TASK_INTERRUPTIBLE). Once running and dealing with actually delivering
the events, we're obviously not planning on calling schedule, thus we can
relax the implied barrier and simply update the state with
__set_current_state().
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index d77f944..1e009ca 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -1639,9 +1639,9 @@
spin_lock_irqsave(&ep->lock, flags);
}
- __remove_wait_queue(&ep->wq, &wait);
- set_current_state(TASK_RUNNING);
+ __remove_wait_queue(&ep->wq, &wait);
+ __set_current_state(TASK_RUNNING);
}
check_events:
/* Is it worth to try to dig for events ? */