Andi Kleen <a...@firstfloor.org> writes:
> Bertrand Jacquin <be...@meleeweb.net> writes:
>>  
>> +# CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
>> +# after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
>> +# or CONFIG_MODULE_COMPRESS_XZ.
>> +
>> +mod_compress_cmd = true
>> +ifdef CONFIG_MODULE_COMPRESS
>> +  ifdef CONFIG_MODULE_COMPRESS_GZIP
>> +    mod_compress_cmd = gzip -n -9
>
> Please don't use gzip -9. The gain is very small, but it can make
> the time to compress much longer. Just use plain gzip.

Interesting:

$ time find * -name '*.ko' | xargs -n 1 gzip
real    0m9.404s
user    0m7.283s
sys     0m1.667s
$ du -c `find * -name '*.ko.gz'` | tail -n1
56412   total

time find * -name '*.ko' | xargs -n 1 gzip -9
real    1m1.968s
user    0m58.850s
sys     0m1.786s
$ du -c `find * -name '*.ko.gz'` | tail -n1
55764   total

$ time find * -name '*.ko' | xargs -n 1 xz
real    1m23.396s
user    1m13.893s
sys     0m9.134s
$ du -c `find * -name '*.ko.xz` | tail -n1
46868   total

$ time find * -name '*.ko' | xargs -n 1 xz -9
real    1m47.202s
user    1m25.962s
sys     0m21.298s
$ du -c `find * -name '*.ko.xz` | tail -n1
46868   total

So, Andi is right.  Please skip -9 for both options: it makes little
(.gz) or no (.xz) difference and it slows things down.

Cheers,
Rusty.
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