• Theodore Ts'o's avatar
    [GFS2] inode_diet: Replace inode.u.generic_ip with inode.i_private (gfs) · bba9dfd8
    Theodore Ts'o authored
    The following patches reduce the size of the VFS inode structure by 28 bytes
    on a UP x86.  (It would be more on an x86_64 system).  This is a 10% reduction
    in the inode size on a UP kernel that is configured in a production mode
    (i.e., with no spinlock or other debugging functions enabled; if you want to
    save memory taken up by in-core inodes, the first thing you should do is
    disable the debugging options; they are responsible for a huge amount of bloat
    in the VFS inode structure).
    
    This patch:
    
    The filesystem or device-specific pointer in the inode is inside a union,
    which is pretty pointless given that all 30+ users of this field have been
    using the void pointer.  Get rid of the union and rename it to i_private, with
    a comment to explain who is allowed to use the void pointer.  This is just a
    cleanup, but it allows us to reuse the union 'u' for something something where
    the union will actually be used.
    Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
    Cc: Steven Whitehouse <swhiteho@redhat.com>
    Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
    bba9dfd8
debug_fs.c 8.6 KB