lkml.org 
[lkml]   [2006]   [Dec]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[FSAIO][PATCH 3/8] Routines to initialize and test a wait bit key

    init_wait_bit_key() initializes the key field in an already
    allocated wait bit structure, useful for async wait bit support.
    Also separate out the wait bit test to a common routine which
    can be used by different kinds of wakeup callbacks.

    Signed-off-by: Suparna Bhattacharya <suparna@in.ibm.com>
    Acked-by: Ingo Molnar <mingo@elte.hu>
    ---

    linux-2.6.20-rc1-root/include/linux/wait.h | 24 ++++++++++++++++++++++++
    linux-2.6.20-rc1-root/kernel/wait.c | 11 ++---------
    2 files changed, 26 insertions(+), 9 deletions(-)

    diff -puN include/linux/wait.h~init-wait-bit-key include/linux/wait.h
    --- linux-2.6.20-rc1/include/linux/wait.h~init-wait-bit-key 2006-12-21 08:45:46.000000000 +0530
    +++ linux-2.6.20-rc1-root/include/linux/wait.h 2006-12-21 08:45:46.000000000 +0530
    @@ -108,6 +108,17 @@ static inline int waitqueue_active(wait_
    return !list_empty(&q->task_list);
    }

    +static inline int test_wait_bit_key(wait_queue_t *wait,
    + struct wait_bit_key *key)
    +{
    + struct wait_bit_queue *wait_bit
    + = container_of(wait, struct wait_bit_queue, wait);
    +
    + return (wait_bit->key.flags == key->flags &&
    + wait_bit->key.bit_nr == key->bit_nr &&
    + !test_bit(key->bit_nr, key->flags));
    +}
    +
    /*
    * Used to distinguish between sync and async io wait context:
    * sync i/o typically specifies a NULL wait queue entry or a wait
    @@ -416,6 +427,19 @@ int wake_bit_function(wait_queue_t *wait
    INIT_LIST_HEAD(&(wait)->task_list); \
    } while (0)

    +#define init_wait_bit_key(waitbit, word, bit) \
    + do { \
    + (waitbit)->key.flags = word; \
    + (waitbit)->key.bit_nr = bit; \
    + } while (0)
    +
    +#define init_wait_bit_task(waitbit, tsk) \
    + do { \
    + (waitbit)->wait.private = tsk; \
    + (waitbit)->wait.func = wake_bit_function; \
    + INIT_LIST_HEAD(&(waitbit)->wait.task_list); \
    + } while (0)
    +
    /**
    * wait_on_bit - wait for a bit to be cleared
    * @word: the word being waited on, a kernel virtual address
    diff -puN kernel/wait.c~init-wait-bit-key kernel/wait.c
    --- linux-2.6.20-rc1/kernel/wait.c~init-wait-bit-key 2006-12-21 08:45:46.000000000 +0530
    +++ linux-2.6.20-rc1-root/kernel/wait.c 2006-12-28 09:32:44.000000000 +0530
    @@ -139,16 +139,9 @@ EXPORT_SYMBOL(autoremove_wake_function);

    int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *arg)
    {
    - struct wait_bit_key *key = arg;
    - struct wait_bit_queue *wait_bit
    - = container_of(wait, struct wait_bit_queue, wait);
    -
    - if (wait_bit->key.flags != key->flags ||
    - wait_bit->key.bit_nr != key->bit_nr ||
    - test_bit(key->bit_nr, key->flags))
    + if (!test_wait_bit_key(wait, arg))
    return 0;
    - else
    - return autoremove_wake_function(wait, mode, sync, key);
    + return autoremove_wake_function(wait, mode, sync, arg);
    }
    EXPORT_SYMBOL(wake_bit_function);

    _
    --
    Suparna Bhattacharya (suparna@in.ibm.com)
    Linux Technology Center
    IBM Software Lab, India
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2006-12-28 09:37    [W:0.026 / U:0.588 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site