[PATCH 1/2] epoll: hoist out duplicated wake up logic

From: Eric Wong
Date: Sun Mar 03 2013 - 22:06:43 EST


This makes the kernel slightly smaller, and hopefully easier to follow.

Signed-off-by: Eric Wong <normalperson@xxxxxxxx>
Cc: Davide Libenzi <davidel@xxxxxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/eventpoll.c | 27 +++++++++++----------------
1 file changed, 11 insertions(+), 16 deletions(-)

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 5a1a596..6a70b7d 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -536,6 +536,13 @@ static void ep_unregister_pollwait(struct eventpoll *ep, struct epitem *epi)
}
}

+static int __must_check ep_wake_up_locked(struct eventpoll *ep)
+{
+ if (waitqueue_active(&ep->wq))
+ wake_up_locked(&ep->wq);
+ return waitqueue_active(&ep->poll_wait);
+}
+
/**
* ep_scan_ready_list - Scans the ready list in a way that makes possible for
* the scan code, to call f_op->poll(). Also allows for
@@ -620,10 +627,7 @@ static int ep_scan_ready_list(struct eventpoll *ep,
* Wake up (if active) both the eventpoll wait list and
* the ->poll() wait list (delayed after we release the lock).
*/
- if (waitqueue_active(&ep->wq))
- wake_up_locked(&ep->wq);
- if (waitqueue_active(&ep->poll_wait))
- pwake++;
+ pwake = ep_wake_up_locked(ep);
}
spin_unlock_irqrestore(&ep->lock, flags);

@@ -991,10 +995,7 @@ static int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync, void *k
* Wake up ( if active ) both the eventpoll wait list and the ->poll()
* wait list.
*/
- if (waitqueue_active(&ep->wq))
- wake_up_locked(&ep->wq);
- if (waitqueue_active(&ep->poll_wait))
- pwake++;
+ pwake = ep_wake_up_locked(ep);

out_unlock:
spin_unlock_irqrestore(&ep->lock, flags);
@@ -1250,10 +1251,7 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event,
__pm_stay_awake(epi->ws);

/* Notify waiting tasks that events are available */
- if (waitqueue_active(&ep->wq))
- wake_up_locked(&ep->wq);
- if (waitqueue_active(&ep->poll_wait))
- pwake++;
+ pwake = ep_wake_up_locked(ep);
}

spin_unlock_irqrestore(&ep->lock, flags);
@@ -1360,10 +1358,7 @@ static int ep_modify(struct eventpoll *ep, struct epitem *epi, struct epoll_even
__pm_stay_awake(epi->ws);

/* Notify waiting tasks that events are available */
- if (waitqueue_active(&ep->wq))
- wake_up_locked(&ep->wq);
- if (waitqueue_active(&ep->poll_wait))
- pwake++;
+ pwake = ep_wake_up_locked(ep);
}
spin_unlock_irq(&ep->lock);
}
--
1.8.1.2.526.gf51a757

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