kbuild: add variables for compression tools

Allow user to use alternative implementations of compression tools,
such as pigz, pbzip2, pxz. For example, multi-threaded tools to
speed up the build:
$ make GZIP=pigz BZIP2=pbzip2

Variables _GZIP, _BZIP2, _LZOP are used internally because original env
vars are reserved by the tools. The use of GZIP in gzip tool is obsolete
since 2015. However, alternative implementations (e.g., pigz) still rely
on it. BZIP2, BZIP, LZOP vars are not obsolescent.

The credit goes to @grsecurity.

As a sidenote, for multi-threaded lzma, xz compression one can use:
$ export XZ_OPT="--threads=0"

Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This commit is contained in:
Denis Efremov
2020-06-05 10:39:55 +03:00
committed by Masahiro Yamada
parent e0b250b57d
commit 8dfb61dcba
10 changed files with 45 additions and 24 deletions

View File

@@ -28,15 +28,15 @@ case "${1}" in
opts=
;;
targz-pkg)
opts=--gzip
opts="-I ${_GZIP}"
tarball=${tarball}.gz
;;
tarbz2-pkg)
opts=--bzip2
opts="-I ${_BZIP2}"
tarball=${tarball}.bz2
;;
tarxz-pkg)
opts=--xz
opts="-I ${XZ}"
tarball=${tarball}.xz
;;
*)