[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: multi threaded support for xz



[Please keep me in CC. I'm not subscribed.]

Sebastian Andrzej Siewior:
> xz-utils 5.2.2 with threading support for the compressor is currently
> in the deferred queue for another 24 hours [0].
> Once this version has been built a binNMU of dpkg will pick up the
> threading support. dpkg will the use the number of online CPUs for
> compression [1] in a "dpkg-deb -b" invocation.

Is the new multi-thread compressor reproducible? I.e. does it produce
the same output regardless of the number of CPUs, the CPU speed, system
load, etc.? (A very quick look at the source suggest that this is not
the case but I might be totally mistaken)

This would be rather bad for dpkg since it would make effectively any
package unreproducible [3].

> [0] https://ftp-master.debian.org/deferred.html
> [1] https://sources.debian.net/src/dpkg/1.18.10/lib/dpkg/compress.c/#L534
> [2] https://git.breakpoint.cc/cgit/bigeasy/xz-utils-debian.git/tree/src/xz/coder.c#n273

[3]: https://reproducible-builds.org/

Attachment: signature.asc
Description: OpenPGP digital signature


Reply to: