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    SubjectResults of actual compile printk format compression
    Just a quick note...

    Although my experiments with kernel printk format string compression
    have reported estimated shrinkage, this is the first time I have been
    able to compile a whole kernel with the compression filter.

    These results come from doing an allyesconfig of 2.5.68 and then weeding
    out anything that didn't build. One program extracts strings from
    preprocessor output, a second program determines how the strings will be
    encoded, and the third makes substitutions during a kernel compile.

    The uncompressed compile resulted in a kernel image of 24011892 bytes.
    The resulting image with format strings compressed is 23904708 bytes
    which is a shrinkage of 107184 bytes. Subtracting out an estimate of 3K
    for the dictionary and necessary modifications to printk, that results
    in a reduction of something like 104112 which is 4% of the original
    kernel size.

    That may not seem like a lot, but if you consider only the printk
    strings themselves, they are compressed to less than 50% of their
    original size (counting the dictionary but not printk code mods).

    So, I ask... is this a useful savings? Is there any chance anyone would
    bother to increase their compile time by a factor of 5 in order to shave
    off 4% or 100k bytes?

    (Not to mention that allyesconfig is a very unrealistic scenario.)

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      Last update: 2005-03-22 13:36    [W:0.018 / U:4.156 seconds]
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