Re: [PATCH 1/3] xz: add arch-specific tuning for alpha

[Lasse Collin]

On 2026-09-12 Matt Turner wrote:
> Alpha has fixed-length, 4-byte-aligned instructions and no XZ BCJ
> filter, so it wants the same LZMA2 settings as the other
> 4-byte-aligned targets. Without an entry it hits the default case,
> which warns
> 
>   scripts/xz_wrap.sh: Arch-specific tuning is missing for 'alpha'
> 
> and conservatively assumes 2-byte alignment. Alpha gains
> HAVE_KERNEL_XZ later in this series; the correct alignment also
> shrinks a UP1500 kernel's XZ image from 6469320 to 6448840 bytes.
> 
> Signed-off-by: Matt Turner <mattst88@xxxxxxxxx>
> ---
>  scripts/xz_wrap.sh | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/scripts/xz_wrap.sh b/scripts/xz_wrap.sh
> index f19369687030..5af0d9045cbc 100755
> --- a/scripts/xz_wrap.sh
> +++ b/scripts/xz_wrap.sh
> @@ -10,6 +10,7 @@
>  # XZ-compressed kernel isn't currently supported on every listed arch.
>  #   Arch        Align   Notes
> +#   alpha         4
>  #   arm          2/4    ARM and ARM-Thumb2
>  #   arm64         4
>  #   csky          2
> @@ -44,6 +45,10 @@ BCJ=
>  # Set the BCJ filter if one is available.
>  # It must match the #ifdef usage in lib/decompress_unxz.c.
>  case $SRCARCH in
> +	alpha)
> +		ALIGN=4
> +		;;
> +
>  	arm)
>  		if is_enabled CONFIG_THUMB2_KERNEL; then
>  			ALIGN=2
> 

Thanks for Cc'ing me. For this patch:

Reviewed-by: Lasse Collin <lasse.collin@xxxxxxxxxxx>

I looked at the other patches too and didn't see any issues around the
decompressor usage, but I didn't really review them.

-- 
Lasse Collin