On 11/9/22 03:06, Xi Ruoyao via Gcc-patches wrote:
On Wed, 2022-11-09 at 01:52 +0000, Joseph Myers wrote:
On Tue, 8 Nov 2022, Xi Ruoyao via Gcc-patches wrote:
I'm wondering if running xz -T0 on different machines (with different
core numbers) may produce different compressed data. The difference can
cause trouble distributing checksums.
gcc_release definitely doesn't use any options to make the tar file
reproducible (the timestamps, user and group names and ordering of the
files in the tarball, and quite likely permissions other than whether a
file has execute permission, may depend on when the script was run and on
what system as what user - not just on the commit from which the tar file
was built). So I don't think possible variation of xz output matters here
at present.
OK then. I'm already using commands like
git archive --format=tar --prefix=gcc-$(git gcc-descr HEAD)/ HEAD | xz -T0 >
../gcc-$(git gcc-descr HEAD).tar.xz
when I generate a GCC snapshot tarball for my own use.
Hi.
We may consider using zstd compression that also support a multi-threaded
compression
(which is stable). Note the decompression of zstd is much faster than xz.
Martin
