Hi,
On Sat, Jan 27, 2018 at 10:38:12AM +0100, Carsten Schoenert wrote:
> Package: git-buildpackage
> Version: 0.9.6
> Severity: wishlist
>
> Hi,
>
> while doing packaging work on packages which have several hundreds or
> gigabytes if source code files it takes currently a long time to import
> new upstream tarballs which uses xz for compression. The same amount of
> time is needed if gbp needs to recreate the tarball from the upstream
> branch. This happens because the xz command is called without option
> '-T|--threads [x]' and thus only one thread is used to do the
> compression.
>
> I've hacked compressor.py a bit to let gbp call 'xz -T 0 ...' for using
> the maximum of threads and this is decreasing the time xz needs
> significantly. On my quad core machine about about a quarter of the time
> as before.
>
> diff --git a/gbp/pkg/compressor.py b/gbp/pkg/compressor.py
> index b1b795f..a345b34 100644
> --- a/gbp/pkg/compressor.py
> +++ b/gbp/pkg/compressor.py
> @@ -24,7 +24,7 @@ class Compressor(object):
> Opts = {'gzip': '-n',
> 'bzip2': '',
> 'lzma': '',
> - 'xz': ''}
> + 'xz': '"-T 0"'}
>
> Exts = {'gzip': 'gz',
> 'bzip2': 'bz2',
>
> But currently pristine-tar may stumble about tarballs which created by
> this option, please see #869191 for details. The provided patch in
> #869191 is fixing the problems so far for me.
>
> If possible gbp could become a at least a option for setting up the
> number of threads the xz commend will use as long pristine-tar isn't
> working properly with all kinds xz archives?
We should not do more options. Multi threaded should be on when:
- not using pristine-tar
- iff pristine-tar can handle it
The first one is simple but what about the second?
Cheers,
-- Guido
