Commits
Masahiro Yamada committed c15a3d8f5ec
kbuild: make single target builds even faster
commit b1fbfcb4a20949df08dd995927cdc5ad220c128d upstream.
Commit 2dffd23f81a3 ("kbuild: make single target builds much faster")
made the situation much better.
To improve it even more, apply the similar idea to the top Makefile.
Trim unrelated directories from build-dirs.
The single build code must be moved above the 'descend' target.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>