Re: [PATCH 0/3] ARM ZSTD boot compression

From: Arnd Bergmann
Date: Wed Apr 12 2023 - 17:34:27 EST


On Wed, Apr 12, 2023, at 23:21, Jonathan Neuschäfer wrote:
> This patchset enables ZSTD kernel (de)compression on 32-bit ARM.
> Unfortunately, it is much slower than I hoped (tested on ARM926EJ-S):
>
> - LZO: 7.2 MiB, 6 seconds
> - ZSTD: 5.6 MiB, 60 seconds

That seems unexpected, as the usual numbers say it's about 25%
slower than LZO. Do you have an idea why it is so much slower
here? How long does it take to decompress the
generated arch/arm/boot/Image file in user space on the same
hardware using lzop and zstd?

Arnd