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    SubjectRe: [RFC] LZO de/compression support - take 6
    On 5/30/07, Daniel Hazelton <> wrote:
    > I just noticed a bug in my testbed/benchmarking code. It's fixed, but I
    > decided to compare version 6 of the code against the *unsafe* decompressor
    > again. The results of the three runs I've put it through after changing it to
    > compare against the unsafe decompressor were startling. `Tiny's` compressor
    > is still faster - I've seen it be rated up to 3% faster. The decompressor,
    > OTOH, when compared to the unsafe version (which is the comparison that
    > started me on this binge of hacking), is more than 7% worse. About 11% slower
    > on the original test against a C source file, and about 6% slower for random
    > data.

    Unsafe vs safe is within 10%. Its okay.

    > However, looking at the numbers involved, I can't see a reason to keep
    > the unsafe version around - the percentages look worse than they are - from 1
    > to 3 microseconds.

    Not just numbers. Most of applications cannot afford to use unsafe
    versions anyway (like fs people).

    (well, the compressed-cache people might want those extra
    > usecs - but the difference will never be noticeable anywhere outside the
    > kernel)
    > DRH

    compressed cache people require every single percent of that
    performance. For now, ccaching is not ready for mainline (many things
    need to be done). So, till then I will keep off the unsafe version. If
    ever compressed caching is on its way to mainline _then_ I will try
    and add back the unsafe version. But I see no other project that
    really cares about unsafe version so it's okay to keep it off.

    - Nitin
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      Last update: 2007-05-30 07:23    [W:0.020 / U:5.796 seconds]
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