lkml.org 
[lkml]   [2006]   [Dec]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[patch] aio: remove spurious ring head index modulo info->nr
    Date
    In aio_read_evt(), the ring->head will never wrap info->nr because
    we already does the wrap when updating the ring head index:

    if (head != ring->tail) {
    ...
    head = (head + 1) % info->nr;
    ring->head = head;
    }

    This makes the modulo of ring->head into local variable head unnecessary.
    This patch removes that bogus code.


    Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>


    --- ./fs/aio.c.orig 2006-12-24 22:01:36.000000000 -0800
    +++ ./fs/aio.c 2006-12-24 22:34:48.000000000 -0800
    @@ -1019,7 +1019,7 @@ static int aio_read_evt(struct kioctx *i
    {
    struct aio_ring_info *info = &ioctx->ring_info;
    struct aio_ring *ring;
    - unsigned long head;
    + unsigned int head;
    int ret = 0;

    ring = kmap_atomic(info->ring_pages[0], KM_USER0);
    @@ -1032,7 +1032,7 @@ static int aio_read_evt(struct kioctx *i

    spin_lock(&info->ring_lock);

    - head = ring->head % info->nr;
    + head = ring->head;
    if (head != ring->tail) {
    struct io_event *evp = aio_ring_event(info, head, KM_USER1);
    *ent = *evp;
    -
    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: 2006-12-30 04:01    [W:0.023 / U:181.852 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site