Re: Emacs 23.0 is much slower starting than Emacs 22.3

[Richard M. Stallman]

    OTOH the normal-mode call is noticeably slower for emacs23 (though
    not as pronounced as on your w32 - of course, the emacs23 normal-mode 
    code path includes more file attribute usage due to the .dir.settings.el 
    stuff...)

Does `normal-mode' look for the that file more than once in a given
directory?  If so, that is an easy optimization: record the directories
in which it has looked for that file, and don't look again.