# git gc
# git rev-parse -q --verify b923f1247b72fc100b87792fd2129d026bb10e66^{commit}
b923f1247b72fc100b87792fd2129d026bb10e66
already have revision, skipping fetch
# git checkout -q -f -B kisskb b923f1247b72fc100b87792fd2129d026bb10e66
# git clean -qxdf
# < git log -1
# commit b923f1247b72fc100b87792fd2129d026bb10e66
# Merge: b6b178e38f40 b0294f30256b
# Author: Linus Torvalds <torvalds@linux-foundation.org>
# Date:   Fri Aug 14 14:26:08 2020 -0700
# 
#     Merge tag 'timers-urgent-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
#     
#     Pull timekeeping updates from Thomas Gleixner:
#      "A set of timekeeping/VDSO updates:
#     
#        - Preparatory work to allow S390 to switch over to the generic VDSO
#          implementation.
#     
#          S390 requires that the VDSO data pointer is handed in to the
#          counter read function when time namespace support is enabled.
#          Adding the pointer is a NOOP for all other architectures because
#          the compiler is supposed to optimize that out when it is unused in
#          the architecture specific inline. The change also solved a similar
#          problem for MIPS which fortunately has time namespaces not yet
#          enabled.
#     
#          S390 needs to update clock related VDSO data independent of the
#          timekeeping updates. This was solved so far with yet another
#          sequence counter in the S390 implementation. A better solution is
#          to utilize the already existing VDSO sequence count for this. The
#          core code now exposes helper functions which allow to serialize
#          against the timekeeper code and against concurrent readers.
#     
#          S390 needs extra data for their clock readout function. The initial
#          common VDSO data structure did not provide a way to add that. It
#          now has an embedded architecture specific struct embedded which
#          defaults to an empty struct.
#     
#          Doing this now avoids tree dependencies and conflicts post rc1 and
#          allows all other architectures which work on generic VDSO support
#          to work from a common upstream base.
#     
#        - A trivial comment fix"
#     
#     * tag 'timers-urgent-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
#       time: Delete repeated words in comments
#       lib/vdso: Allow to add architecture-specific vdso data
#       timekeeping/vsyscall: Provide vdso_update_begin/end()
#       vdso/treewide: Add vdso_data pointer argument to __arch_get_hw_counter()
# < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/arm-linux-gnueabi/bin/arm-linux-gnueabi-gcc --version
# < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/arm-linux-gnueabi/bin/arm-linux-gnueabi-ld --version
# < git log --format=%s --max-count=1 b923f1247b72fc100b87792fd2129d026bb10e66
# < make -s -j 24 ARCH=arm O=/kisskb/build/linus_bcm2835_defconfig_arm-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/arm-linux-gnueabi/bin/arm-linux-gnueabi-  bcm2835_defconfig
# < make -s -j 24 ARCH=arm O=/kisskb/build/linus_bcm2835_defconfig_arm-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/arm-linux-gnueabi/bin/arm-linux-gnueabi-  help
# make -s -j 24 ARCH=arm O=/kisskb/build/linus_bcm2835_defconfig_arm-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/arm-linux-gnueabi/bin/arm-linux-gnueabi-  olddefconfig
# make -s -j 24 ARCH=arm O=/kisskb/build/linus_bcm2835_defconfig_arm-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/arm-linux-gnueabi/bin/arm-linux-gnueabi-  
In file included from /kisskb/src/kernel/rcu/update.c:591:0:
/kisskb/src/kernel/rcu/tasks.h:593:13: warning: 'show_rcu_tasks_classic_gp_kthread' defined but not used [-Wunused-function]
 static void show_rcu_tasks_classic_gp_kthread(void) { }
             ^
Completed OK
# rm -rf /kisskb/build/linus_bcm2835_defconfig_arm-gcc4.9
# Build took: 0:06:34.959471