[PATCH 5.4 206/214] kheaders: optimize md5sum calculation for in-tree builds

Greg Kroah-Hartman
2020-09-01T16:14:40Z

From: Masahiro Yamada <yamada.masahiro@socionext.com>

commit 0e11773e76098729552b750ccff79374d1e62002 upstream.

This script computes md5sum of headers in srctree and in objtree.
However, when we are building in-tree, we know the srctree and the
objtree are the same. That is, we end up with the same computation
twice. In fact, the first two lines of kernel/kheaders.md5 are always
the same for in-tree builds.

Unify the two md5sum calculations.

For in-tree builds ($building_out_of_srctree is empty), we check
only two directories, "include", and "arch/$SRCARCH/include".

For out-of-tree builds ($building_out_of_srctree is 1), we check
4 directories, "$srctree/include", "$srctree/arch/$SRCARCH/include",
"include", and "arch/$SRCARCH/include" since we know they are all
different.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
kernel/gen_kheaders.sh | 32 ++++++++++++++++----------------
1 file changed, 16 insertions(+), 16 deletions(-)

--- a/kernel/gen_kheaders.sh
+++ b/kernel/gen_kheaders.sh
@@ -21,29 +21,30 @@ arch/$SRCARCH/include/
# Uncomment it for debugging.
# if [ ! -f /tmp/iter ]; then iter=1; echo 1 > /tmp/iter;
# else iter=$(($(cat /tmp/iter) + 1)); echo $iter > /tmp/iter; fi
-# find $src_file_list -name "*.h" | xargs ls -l > /tmp/src-ls-$iter
-# find $obj_file_list -name "*.h" | xargs ls -l > /tmp/obj-ls-$iter
+# find $all_dirs -name "*.h" | xargs ls -l > /tmp/ls-$iter
+
+all_dirs=
+if [ "$building_out_of_srctree" ]; then
+ for d in $dir_list; do
+ all_dirs="$all_dirs $srctree/$d"
+ done
+fi
+all_dirs="$all_dirs $dir_list"

# include/generated/compile.h is ignored because it is touched even when none
# of the source files changed. This causes pointless regeneration, so let us
# ignore them for md5 calculation.
-pushd $srctree > /dev/null
-src_files_md5="$(find $dir_list -name "*.h" |
- grep -v "include/generated/compile.h" |
- grep -v "include/generated/autoconf.h" |
- xargs ls -l | md5sum | cut -d ' ' -f1)"
-popd > /dev/null
-obj_files_md5="$(find $dir_list -name "*.h" |
- grep -v "include/generated/compile.h" |
- grep -v "include/generated/autoconf.h" |
+headers_md5="$(find $all_dirs -name "*.h" |
+ grep -v "include/generated/compile.h" |
+ grep -v "include/generated/autoconf.h" |
xargs ls -l | md5sum | cut -d ' ' -f1)"
+
# Any changes to this script will also cause a rebuild of the archive.
this_file_md5="$(ls -l $sfile | md5sum | cut -d ' ' -f1)"
if [ -f $tarfile ]; then tarfile_md5="$(md5sum $tarfile | cut -d ' ' -f1)"; fi
if [ -f kernel/kheaders.md5 ] &&
- [ "$(head -n 1 kernel/kheaders.md5)" = "$src_files_md5" ] &&
- [ "$(head -n 2 kernel/kheaders.md5 | tail -n 1)" = "$obj_files_md5" ] &&
- [ "$(head -n 3 kernel/kheaders.md5 | tail -n 1)" = "$this_file_md5" ] &&
+ [ "$(head -n 1 kernel/kheaders.md5)" = "$headers_md5" ] &&
+ [ "$(head -n 2 kernel/kheaders.md5 | tail -n 1)" = "$this_file_md5" ] &&
[ "$(tail -n 1 kernel/kheaders.md5)" = "$tarfile_md5" ]; then
exit
fi
@@ -79,8 +80,7 @@ find $cpio_dir -printf "./%P\n" | LC_ALL
--owner=0 --group=0 --numeric-owner --no-recursion \
-Jcf $tarfile -C $cpio_dir/ -T - > /dev/null

-echo "$src_files_md5" > kernel/kheaders.md5
-echo "$obj_files_md5" >> kernel/kheaders.md5
+echo $headers_md5 > kernel/kheaders.md5
echo "$this_file_md5" >> kernel/kheaders.md5
echo "$(md5sum $tarfile | cut -d ' ' -f1)" >> kernel/kheaders.md5