Re: [PATCH] maintainer-scripts/gcc_release: compress xz in parallel

[Xi Ruoyao <xry111@xry111.site>]

On Tue, 2022-11-08 at 07:14 +0000, Sam James via Gcc-patches wrote:
> 1. This should speed up decompression for folks, as parallel xz
>    creates a different archive which can be decompressed in parallel.
> 
>    Note that this different method is enabled by default in a new
>    xz release coming shortly anyway (>= 5.3.3_alpha1).
> 
>    I build GCC regularly from the weekly snapshots
>    and so the decompression time adds up.
> 
> 2. It should speed up compression on the webserver a bit.
> 
>    Note that -T0 won't be the default in the new xz release,
>    only the parallel compression mode (which enables parallel
>    decompression).
> 
>    -T0 detects the number of cores available.
> 
>    So, if a different number of threads is preferred, it's fine
>    to set e.g. -T2, etc.

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.

-- 
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University