[arch-general] [arch-announce] Moving to Zstandard images by default on mkinitcpio

[mike lojkovic]

Those milliseconds matter. When you have a thousand processes starting up
shaving off a couple fractions of a second on each helps you hit the less
than 10 second boot time.

On Sun, Feb 21, 2021 at 4:48 AM Archange via arch-general <
arch-general at lists.archlinux.org> wrote:

> Le 21/02/2021 à 02:56, Geert Hendrickx via arch-general a écrit :
> > On Sat, Feb 20, 2021 at 21:25:21 +0100, mpan via arch-general wrote:
> >>> I benchmarked it on my mkinitcpio image, and zstd with mkinitcpio's […]
> >> Though you have benchmarked a wrong thing. It’s decompression time that
> >> matters here, not compression. The image is compressed to make it load
> >> faster during boot and that’s the important metric here.
> >
> > Compression time matters also, since on many systems an initramfs gets
> > booted only once or a few times for every time one gets generated, and
> > zstd -19 is ridiculously slow for larger files,  However mkinitcpio v30
> > reverted to zstd's default compression level 3, which is much better.
>
> Excepted that decompression is a blocking event for boot, while
> compression is async.
>
> Anyway, based on the benchmark published on the PR that reverted to the
> default level, using -8 seems the best tradeoff for fast compression and
> small size, and −18 if space really is an issue (or you’re reading the
> file from a floppy…).
>
> Also, on most systems nowadays we are talking about changes in the order
> of hundreds of milliseconds, while I take ~5s to type my entire LUKS
> passphrase on boot. So…
>