On 20 November 2012 23:21, Guillem Jover <guil...@debian.org> wrote: > On Sat, 2012-11-10 at 13:52:22 +0100, Bastian Blank wrote: >> On Fri, Nov 09, 2012 at 07:48:22PM +0100, Guillem Jover wrote: >> Okay. I did some tests with various packages. From binary only to text >> only. > > Thanks for the tests Bastian. It would still be nice to see a bigger > sample, if the tests only consisted of these 4 packages, though. > >> Package | gzip -6 | gzip -9 | gzip | xz -1 >> --------------------------+----------+-----------------+--------- >> libc6 | 4339010 | 4321933 | 0.5% | 2938132 >> perl-modules | 3874170 | 3822719 | 1.5% | 3248392 >> gnome-user-guide | 9217494 | 9172395 | 0.5% | 7589076 >> linux-image-3.2.0-4-amd64 | 32928159 | 32522228 | | 25945856 >> >> "gzip -9" is always much slower then "gzip -6". It is at most 2% better. >> "xz -1" is usualy faster then "gzip -9" and much better. However most >> packages only needs seconds to compress, so the difference will no >> really matter. >> >> So instead of switching to gzip -6, a switch to xz -1 would make more >> sense in term of size and also speed. > >> So my proposal would be: >> - Don't do anything for Wheezy. >> Any change may break the CD creation. >> - Switch to xz per default for Jessie. >> xz -3 is often faster in compressing stuff then gzip -9. -6 needs a >> lot of memory, especially for compressing the files, so reducing the >> default to -3 may make sense and does not cost much. > > I've already mentioned in some other thread that for dpkg 1.17.x (that > is after wheezy), I'll be switching dpkg-deb to xz as the default > compressor, as that seemed the consensus; but that does not mean that > if the default compression level for gzip is suboptimal (as it seems > it is), that cannot be changed too. > > For changing xz default compression level I'd like to see the > implications on a wider dataset, also we should take into account that > compression is only done once, so I don't think that's such an issue, > if the time and memory are not really onerous.
While I appreciate the discussions around default compression algorithms and their setting, I'd rather this thread to stay on-topic. Does the idea of providing a standard interface to disable compression make sense? In the approximately similar fashion that noopt and nostrip are justified? This should be a standard interface via DEB_BUILD_OPTIONS, because dh_builddeb / dpkg-deb is not the only way to build compliant binary packages. Please continue discussing default compression options, but please use another thread/topic. Just as I do now, I will continue to want the nocompress option regardless of current or future default/non-default compression algorithms and options. I'd like to gather consensus on how (in)sane this idea is though before submit a patch for debian policy. Regards, Dmitrijs. -- To UNSUBSCRIBE, email to debian-devel-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/CANBHLUh_y+X=bzga5rldy+fvvmcmso0gwhamibc28y+erga...@mail.gmail.com
