# git rev-parse -q --verify fc45f8974252b140023cdccc4a0907853c3ecec8^{commit}
# git fetch -q -n -f https://git.kernel.org/pub/scm/linux/kernel/git/sfr/linux.git test
# git rev-parse -q --verify fc45f8974252b140023cdccc4a0907853c3ecec8^{commit}
fc45f8974252b140023cdccc4a0907853c3ecec8
# git checkout -q -f -B kisskb fc45f8974252b140023cdccc4a0907853c3ecec8
# git clean -qxdf
# < git log -1
# commit fc45f8974252b140023cdccc4a0907853c3ecec8
# Author: Stephen Rothwell <sfr@canb.auug.org.au>
# Date:   Mon Jun 15 18:02:37 2020 +1000
# 
#     major.h: remove the remaining unnecessary includes of linux/major.h
#     
#     Now that very file that needs the definitions in major.h explicitly
#     includes it, this is just cleaning up.
#     
#     This is fairly safe because major.h does not include any other files.
#     The only real risk is if a symbol defined in major.h is constructed by
#     concatenation in the preprocessor.
#     
#     The actual change was done using the following command:
#     
#       sed -i -E '/[<"](uapi\/)?linux\/major\.h/d' \
#         $(grep -L -w -f xx \
#           $(git grep -E -l '[<"](uapi/)?linux/major\.h'))
#     
#     Where the file xx contians all the symbols defined in major.h
#     
#     (genhd.h was added by inspection.)
#     
#     The win here is really just the number of lines to be parsed by the
#     preprocessor.  major.h is 180 lines long and was being included by
#     these files unnecessarily.  In particular, there are 3 global include
#     files here (tty.h, genhd.h and blkdev.h) that are also included by 354,
#     68 and 554 other files, repectively.
#     
#     After this, major.h is only included by 4 global include files (which
#     are in turn included by 297 other files), so its indirect inclusion is
#     hopefully much reduced.
#     
#     Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
# < /opt/cross/kisskb/br-xtensa-full-2016.08-613-ge98b4dd/bin/xtensa-linux-gcc --version
# < /opt/cross/kisskb/br-xtensa-full-2016.08-613-ge98b4dd/bin/xtensa-linux-ld --version
# < git log --format=%s --max-count=1 fc45f8974252b140023cdccc4a0907853c3ecec8
# < make -s -j 10 ARCH=xtensa O=/kisskb/build/sfr-test_xtensa-defconfig_xtensa CROSS_COMPILE=/opt/cross/kisskb/br-xtensa-full-2016.08-613-ge98b4dd/bin/xtensa-linux-  defconfig
# < make -s -j 10 ARCH=xtensa O=/kisskb/build/sfr-test_xtensa-defconfig_xtensa CROSS_COMPILE=/opt/cross/kisskb/br-xtensa-full-2016.08-613-ge98b4dd/bin/xtensa-linux-  help
# make -s -j 10 ARCH=xtensa O=/kisskb/build/sfr-test_xtensa-defconfig_xtensa CROSS_COMPILE=/opt/cross/kisskb/br-xtensa-full-2016.08-613-ge98b4dd/bin/xtensa-linux-  olddefconfig
# make -s -j 10 ARCH=xtensa O=/kisskb/build/sfr-test_xtensa-defconfig_xtensa CROSS_COMPILE=/opt/cross/kisskb/br-xtensa-full-2016.08-613-ge98b4dd/bin/xtensa-linux-  
Completed OK
# rm -rf /kisskb/build/sfr-test_xtensa-defconfig_xtensa
# Build took: 0:01:07.623981