lkml.org 
[lkml]   [2010]   [May]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH] epoll: use wrapper functions
    Date
    use wrapper functions.

    epoll should not touch flags in wait_queue_t. This patch introduces a new
    function add_wait_queue_head_exclusive_locked(), for the users, who use
    wait queue as a LIFO queue.

    Signed-off-by: Changli Gao <xiaosuo@gmail.com>
    ----
    fs/eventpoll.c | 5 ++---
    include/linux/wait.h | 15 +++++++++++++--
    2 files changed, 15 insertions(+), 5 deletions(-)
    diff --git a/fs/eventpoll.c b/fs/eventpoll.c
    index bd056a5..8137f6e 100644
    --- a/fs/eventpoll.c
    +++ b/fs/eventpoll.c
    @@ -1140,8 +1140,7 @@ retry:
    * ep_poll_callback() when events will become available.
    */
    init_waitqueue_entry(&wait, current);
    - wait.flags |= WQ_FLAG_EXCLUSIVE;
    - __add_wait_queue(&ep->wq, &wait);
    + add_wait_queue_head_exclusive_locked(&ep->wq, &wait);

    for (;;) {
    /*
    @@ -1161,7 +1160,7 @@ retry:
    jtimeout = schedule_timeout(jtimeout);
    spin_lock_irqsave(&ep->lock, flags);
    }
    - __remove_wait_queue(&ep->wq, &wait);
    + remove_wait_queue_locked(&ep->wq, &wait);

    set_current_state(TASK_RUNNING);
    }
    diff --git a/include/linux/wait.h b/include/linux/wait.h
    index a48e16b..de2566d 100644
    --- a/include/linux/wait.h
    +++ b/include/linux/wait.h
    @@ -407,17 +407,28 @@ do { \
    * Must be called with the spinlock in the wait_queue_head_t held.
    */
    static inline void add_wait_queue_exclusive_locked(wait_queue_head_t *q,
    - wait_queue_t * wait)
    + wait_queue_t *wait)
    {
    wait->flags |= WQ_FLAG_EXCLUSIVE;
    __add_wait_queue_tail(q, wait);
    }

    /*
    + * Must be called with the spinlock in the wait_queue_head_t held, and
    + * q must be for exclusive wait only.
    + */
    +static inline void add_wait_queue_head_exclusive_locked(wait_queue_head_t *q,
    + wait_queue_t *wait)
    +{
    + wait->flags |= WQ_FLAG_EXCLUSIVE;
    + __add_wait_queue(q, wait);
    +}
    +
    +/*
    * Must be called with the spinlock in the wait_queue_head_t held.
    */
    static inline void remove_wait_queue_locked(wait_queue_head_t *q,
    - wait_queue_t * wait)
    + wait_queue_t *wait)
    {
    __remove_wait_queue(q, wait);
    }

    \
     
     \ /
      Last update: 2010-05-06 06:21    [W:0.020 / U:3.316 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site