# git rev-parse -q --verify 23c35f48f5fbe33f68904138b23fee64df7d2f0f^{commit}
23c35f48f5fbe33f68904138b23fee64df7d2f0f
already have revision, skipping fetch
# git checkout -q -f -B kisskb 23c35f48f5fbe33f68904138b23fee64df7d2f0f
# git clean -qxdf
# git log -1
commit 23c35f48f5fbe33f68904138b23fee64df7d2f0f
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Fri Feb 2 16:44:14 2018 -0800

    pinctrl: remove include file from <linux/device.h>
    
    When pulling the recent pinctrl merge, I was surprised by how a
    pinctrl-only pull request ended up rebuilding basically the whole
    kernel.
    
    The reason for that ended up being that <linux/device.h> included
    <linux/pinctrl/devinfo.h>, so any change to that file ended up causing
    pretty much every driver out there to be rebuilt.
    
    The reason for that was because 'struct device' has this in it:
    
        #ifdef CONFIG_PINCTRL
            struct dev_pin_info     *pins;
        #endif
    
    but we already avoid header includes for these kinds of things in that
    header file, preferring to just use a forward-declaration of the
    structure instead.  Exactly to avoid this kind of header dependency.
    
    Since some drivers seem to expect that <linux/pinctrl/devinfo.h> header
    to come in automatically, move the include to <linux/pinctrl/pinctrl.h>
    instead.  It might be better to just make the includes more targeted,
    but I'm not going to review every driver.
    
    It would definitely be good to have a tool for finding and minimizing
    header dependencies automatically - or at least help with them.  Right
    now we almost certainly end up having way too many of these things, and
    it's hard to test every single configuration.
    
    FWIW, you can get a sense of the "hotness" of a header file with something
    like this after doing a full build:
    
        find . -name '.*.o.cmd' -print0 |
            xargs -0 tail --lines=+2 |
            grep -v 'wildcard ' |
            tr ' \\' '\n' |
            sort | uniq -c | sort -n | less -S
    
    which isn't exact (there are other things in those '*.o.cmd' than just
    the dependencies, and the "--lines=+2" only removes the header), but
    might a useful approximation.
    
    With this patch, <linux/pinctrl/devinfo.h> drops to "only" having 833
    users in the current x86-64 allmodconfig.  In contrast, <linux/device.h>
    has 14857 build files including it directly or indirectly.
    
    Of course, the headers that absolutely _everybody_ includes (things like
    <linux/types.h> etc) get a score of 23000+.
    
    Cc: Linus Walleij <linus.walleij@linaro.org>
    Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/i386-linux/bin/i386-linux-gcc --version
# < git log --format=%s --max-count=1 23c35f48f5fbe33f68904138b23fee64df7d2f0f
# < make -j 120 ARCH=i386 O=/home/kisskb/slave/build/linus_i386-randconfig_i386 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/i386-linux/bin/i386-linux-  randconfig
KCONFIG_SEED=0x85B1FD3E
# Added to kconfig CONFIG_STANDALONE=y
# Added to kconfig CONFIG_PREVENT_FIRMWARE_BUILD=y
# yes \n | make -j 120 ARCH=i386 O=/home/kisskb/slave/build/linus_i386-randconfig_i386 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/i386-linux/bin/i386-linux-  oldconfig
yes: standard output: Broken pipe
yes: write error
# make -j 120 ARCH=i386 O=/home/kisskb/slave/build/linus_i386-randconfig_i386 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/i386-linux/bin/i386-linux-  
make[1]: Entering directory '/home/kisskb/slave/build/linus_i386-randconfig_i386'
  GEN     ./Makefile
scripts/kconfig/conf  --silentoldconfig Kconfig
  SYSTBL  arch/x86/include/generated/asm/syscalls_32.h
  SYSHDR  arch/x86/include/generated/uapi/asm/unistd_32.h
  SYSHDR  arch/x86/include/generated/uapi/asm/unistd_64.h
  SYSHDR  arch/x86/include/generated/uapi/asm/unistd_x32.h
  CHK     include/config/kernel.release
Cannot use CONFIG_CC_STACKPROTECTOR_REGULAR: -fstack-protector available but compiler is broken
/home/kisskb/slave/src/Makefile:1102: recipe for target 'prepare-compiler-check' failed
make[1]: *** [prepare-compiler-check] Error 1
make[1]: *** Waiting for unfinished jobs....
  UPD     include/config/kernel.release
make[1]: *** wait: No child processes.  Stop.
Makefile:146: recipe for target 'sub-make' failed
make: *** [sub-make] Error 2
Command 'make -j 120 ARCH=i386 O=/home/kisskb/slave/build/linus_i386-randconfig_i386 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/i386-linux/bin/i386-linux-  ' returned non-zero exit status 2
# rm -rf /home/kisskb/slave/build/linus_i386-randconfig_i386
# Build took: 0:00:06.770844