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  • Theodore Ts'o's avatar
    [PATCH] inode_diet: Replace inode.u.generic_ip with inode.i_private · 8e18e294
    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.
    [ powerpc build fix]
    Signed-off-by: default avatar"Theodore Ts'o" <>
    Signed-off-by: default avatarJudith Lebzelter <>
    Signed-off-by: default avatarAndrew Morton <>
    Signed-off-by: default avatarLinus Torvalds <>