Messages in this thread | | | Date | Thu, 16 Aug 2012 23:25:49 +0600 | From | Roman Mamedov <> | Subject | Re: [GIT PULL] Update LZO compression |
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On Thu, 16 Aug 2012 17:06:47 +0200 Johannes Stezenbach <js@sig21.net> wrote:
> Well, ~2x speedup on x86 is certainly a good achievement, but there > are more ARM based devices than there are PCs, and I guess many > embedded devices use lzo compressed kernels and file systems > while I'm not convinced many PCs rely on lzo in the kernel.
Keep in mind that a major user of LZO is the BTRFS filesystem, and I believe it is used much more often on larger machines than on ARM, in fact it had problems operating on ARM at all, until quite recently.
> I know everyone's either busy or on vacation, but it would > be so cool if someone could test on a more modern ARM core, > with the userspace test code I posted it should be easy to do.
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.
# time for i in {1..20}; do old/unlzop < rnd.lzo >/dev/null ; done
real 0m11.353s user 0m3.060s sys 0m8.170s # time for i in {1..20}; do new/unlzop < rnd.lzo >/dev/null ; done
real 0m11.416s user 0m3.030s sys 0m8.200s # time for i in {1..20}; do test/unlzop < rnd.lzo >/dev/null ; done
real 0m11.310s user 0m3.100s sys 0m8.150s
-- With respect, Roman
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