The 'cpio' command is used solely for copying header files to the
temporary directory. However, there is no strong reason to use 'cpio'
for this purpose. For example, scripts/package/install-extmod-build
uses the 'tar' command to copy files.
This commit replaces the use of 'cpio' with 'tar' because 'tar' is
already used in this script to generate kheaders_data.tar.xz anyway.
Performance-wide, there is no significant difference between 'cpio'
and 'tar'.
[Before]
$ rm -fr kheaders; mkdir kheaders
$ time sh -c '
for f in include arch/x86/include
do
find "$f" -name "*.h"
done | cpio --quiet -pd kheaders
'
real 0m0.148s
user 0m0.021s
sys 0m0.140s
[After]
$ rm -fr kheaders; mkdir kheaders
$ time sh -c '
for f in include arch/x86/include
do
find "$f" -name "*.h"
done | tar -c -f - -T - | tar -xf - -C kheaders
'
real 0m0.098s
user 0m0.024s
sys 0m0.131s
Revert commit 69ef0920bdd3 ("Docs: Add cpio requirement to changes.rst")
because 'cpio' is not used anywhere else during the kernel build. Please
note that the built-in initramfs is created by usr/gen_init_cpio, so it
does not rely on the external 'cpio' command at all.
Remove 'cpio' from the package build dependencies as well.
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---
Documentation/process/changes.rst | 6 ------
kernel/gen_kheaders.sh | 13 ++-----------
scripts/package/PKGBUILD | 1 -
scripts/package/mkdebian | 2 +-
4 files changed, 3 insertions(+), 19 deletions(-)
diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst
index 82b5e378eebf..a0beca805362 100644
--- a/Documentation/process/changes.rst
+++ b/Documentation/process/changes.rst
@@ -59,7 +59,6 @@ iptables 1.4.2 iptables -V
openssl & libcrypto 1.0.0 openssl version
bc 1.06.95 bc --version
Sphinx\ [#f1]_ 2.4.4 sphinx-build --version
-cpio any cpio --version
GNU tar 1.28 tar --version
gtags (optional) 6.6.5 gtags --version
mkimage (optional) 2017.01 mkimage --version
@@ -536,11 +535,6 @@ mcelog
- <https://www.mcelog.org/>
-cpio
-----
-
-- <https://www.gnu.org/software/cpio/>
-
Networking
**********
diff --git a/kernel/gen_kheaders.sh b/kernel/gen_kheaders.sh
index ddfd1177567f..55f493d83b8f 100755
--- a/kernel/gen_kheaders.sh
+++ b/kernel/gen_kheaders.sh
@@ -14,13 +14,6 @@ include/
arch/$SRCARCH/include/
"
-if ! command -v cpio >/dev/null; then
- echo >&2 "***"
- echo >&2 "*** 'cpio' could not be found."
- echo >&2 "***"
- exit 1
-fi
-
# Support incremental builds by skipping archive generation
# if timestamps of files being archived are not changed.
@@ -73,15 +66,13 @@ if [ "$building_out_of_srctree" ]; then
cd $srctree
for f in $dir_list
do find "$f" -name "*.h";
- done | cpio --quiet -pd "${tmpdir}"
+ done | tar -c -f - -T - | tar -xf - -C "${tmpdir}"
)
fi
-# The second CPIO can complain if files already exist which can happen with out
-# of tree builds having stale headers in srctree. Just silence CPIO for now.
for f in $dir_list;
do find "$f" -name "*.h";
-done | cpio --quiet -pdu "${tmpdir}" >/dev/null 2>&1
+done | tar -c -f - -T - | tar -xf - -C "${tmpdir}"
# Always exclude include/generated/utsversion.h
# Otherwise, the contents of the tarball may vary depending on the build steps.
diff --git a/scripts/package/PKGBUILD b/scripts/package/PKGBUILD
index f83493838cf9..b4e474c05a0a 100644
--- a/scripts/package/PKGBUILD
+++ b/scripts/package/PKGBUILD
@@ -22,7 +22,6 @@ license=(GPL-2.0-only)
makedepends=(
bc
bison
- cpio
flex
gettext
kmod
diff --git a/scripts/package/mkdebian b/scripts/package/mkdebian
index b038a1380b8a..b6dd98ca860b 100755
--- a/scripts/package/mkdebian
+++ b/scripts/package/mkdebian
@@ -205,7 +205,7 @@ Priority: optional
Maintainer: $maintainer
Rules-Requires-Root: no
Build-Depends: debhelper-compat (= 12)
-Build-Depends-Arch: bc, bison, cpio, flex,
+Build-Depends-Arch: bc, bison, flex,
gcc-${host_gnu} <!pkg.${sourcename}.nokernelheaders>,
kmod, libelf-dev:native,
libssl-dev:native, libssl-dev <!pkg.${sourcename}.nokernelheaders>,
--
2.43.0
