Re: [PATCH] lib: zstd: update to latest Linux zstd 1.5.7

On Fri, Aug 14, 2026 at 10:37:00PM +0000, Cole Munz wrote:
> Thanks, buildman -B localises it well, and there is an easy win in it.
> 
> Almost all the growth is the new Huffman fast-decode path in 1.5.7. turris_mox
> and mvebu_espressobin-88f3720 give identical breakdowns, text +1896 rodata +24:
> 
>   HUF_decompress4X1_usingDTable_internal                 -    1508   +1508
>   HUF_readDTableX1_wksp                                  8    1312   +1304
>   HUF_decompress4X1_usingDTable_internal_fast_c_loop     -    1092   +1092
>   FSE_decompress_wksp_bmi2                               4     316    +312
> 
> Upstream guards that path with HUF_DISABLE_FAST_DECODE. Adding it to the
> CONFIG_ZSTD_LIB_MINIFY flags in lib/zstd/Makefile, beside the
> HUF_FORCE_DECOMPRESS_X1 and DYNAMIC_BMI2=0 already there, takes turris_mox from
> +1920 to +236 bytes against 1.5.2. Sandbox ut lib still passes 133 tests with 0
> failures, including both zstd cases.
> 
> Trading decode speed for size is what MINIFY is for, so it looks like it
> belongs there rather than on by default.
> 
> Want that as a separate patch on top? I did not fold it in because it changes
> behaviour for existing MINIFY users, not just the library version.

It looks like HUF_DISABLE_FAST_DECODE is a new symbol, so yes, please
respin with that being used under CONFIG_ZSTD_LIB_MINIFY, thanks!

-- 
Tom

-----BEGIN PGP SIGNATURE-----

iHUEABYKAB0WIQTzzqh0PWDgGS+bTHor4qD1Cr/kCgUCan+ivQAKCRAr4qD1Cr/k
CoO7AQCdZNHctc6COlqCMv8rYcqEiXnB1QbEb02jei1YXtkqfAD/Y3akHgzAv5c6
0YxO7Y9BtBELZ/US+y4A/KKLpngENAI=
=WcVX
-----END PGP SIGNATURE-----