• Bob Peterson's avatar
    GFS2: Use single-block reservations for directories · af21ca8e
    Bob Peterson authored
    This patch changes the multi-block allocation code, such that
    directory inodes only get a single block reserved in the bitmap.
    That way, the bitmaps are more tightly packed together, and there
    are fewer spans of free blocks for in-use block reservations.
    This means it takes less time to find a free span of blocks in the
    bitmap, which speeds things up. This increases the performance of
    some workloads by almost 2X. In Nate's mockup.py script (which does
    (1) create dir, (2) create dir in dir, (3) create file in that dir)
    the test executes in 23 steps rather than 43 steps, a 47%
    performance improvement.
    Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
    Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>