Messages in this thread | | | From | Rusty Russell <> | Subject | Re: [PATCH 2/3] kbuild: handle module compression while running 'make modules_install'. | Date | Wed, 20 Aug 2014 03:25:45 +0930 |
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Andi Kleen <andi@firstfloor.org> writes: > Bertrand Jacquin <beber@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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