Re: [GIT PULL] Update LZO compression

[Geert Uytterhoeven]

On Thu, Aug 16, 2012 at 7:52 PM, Andi Kleen <andi@xxxxxxxxxxxxxx> wrote:
>> I have locked the Allwinner A10 CPU in my Mele A2000 to 60 MHz using cpufreq-set,
>> and ran your test. rnd.lzo is a 9 MB file from /dev/urandom compressed with lzo.
>> There doesn't seem to be a significant difference between all three variants.
>
> I found that in compression benchmarks it depends a lot on the data
> compressed.
>
> urandom (which should be essentially incompressible) will be handled
> by different code paths in the compressor than other more compressible data.
> It becomes a complicated memcpy then.

In addition, locking the CPU to 60 MHz may improve the memory access penalty,
as a cache miss may cost much less cycles.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
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