[lkml]   [2006]   [Oct]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [PATCH] splice : two smp_mb() can be omitted
    On Tue, Oct 31 2006, Eric Dumazet wrote:
    > This patch deletes two calls to smp_mb() that were done after
    > mutex_unlock() that contains an implicit memory barrier.
    > The first one in splice_to_pipe(), where 'do_wakeup' is set to true only if
    > pipe->inode is set (and in this case the
    > if (pipe->inode)
    > mutex_unlock(&pipe->inode->i_mutex);
    > is done too)
    > The second one in link_pipe(), following inode_double_unlock() that
    > contains calls to mutex_unlock() too.

    NAK on that patch, the smp_mb() follows the waitqueue_active(). If you
    later change the code and move the locks or whatnot, you have lost that

    If you change the patch to insert a comment, then it may be more

    Jens Axboe

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2006-10-31 08:33    [W:0.025 / U:13.868 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site