• Mikulas Patocka's avatar
    dm crypt: sort writes · b3c5fd30
    Mikulas Patocka authored
    Write requests are sorted in a red-black tree structure and are
    submitted in the sorted order.
    
    In theory the sorting should be performed by the underlying disk
    scheduler, however, in practice the disk scheduler only accepts and
    sorts a finite number of requests.  To allow the sorting of all
    requests, dm-crypt needs to implement its own sorting.
    
    The overhead associated with rbtree-based sorting is considered
    negligible so it is not used conditionally.  Even on SSD sorting can be
    beneficial since in-order request dispatch promotes lower latency IO
    completion to the upper layers.
    Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
    Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
    b3c5fd30
dm-crypt.c 49.5 KB