[PATCH v2 21/21] kbuild: use pigz for gzip compression if available

[Kees Cook]

On Mon, Sep 14, 2026 at 10:22:20AM +0100, Lorenzo Stoakes (ARM) wrote:
> diff --git a/Makefile b/Makefile
> index 790ef23c5e8a..38c0cdc9f591 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -561,7 +561,7 @@ PERL		= perl
>  PYTHON3		= python3
>  CHECK		= sparse
>  BASH		= bash
> -KGZIP		= gzip
> +KGZIP		:= $(if $(shell command -v pigz 2>/dev/null),pigz,gzip)
>  KBZIP2		= bzip2
>  KLZOP		= lzop
>  LZMA		= lzma

I had another idea that I think solves both my concerns (limits
to parallelism, new surprise users) and your concerns (complexity,
single-threaded when needed)... how about:

Makefile:

KPGZIP	:= $(if $(shell command -v pigz 2>/dev/null),$(PYTHON3) $(abs_srctree)/scripts/jobserver-exec $(abs_srctree)/scripts/parallel-gzip,gzip)

and the same scripts/parallel-gzip:

	#!/bin/sh
	exec pigz -p ${PARALLELISM:-1} "$@"

And then replace the /boot/ KGZIP uses with KPGZIP. Then we don't need
to change modules, config_data, new users, nor cmd_gzip, etc, which all
continue to use the regular KGZIP and the "use python" part for the
KPGZIP case becomes is a 1-time cost?

-Kees

-- 
Kees Cook