# git rev-parse -q --verify 07a361072378fb3ae116db86244372dbd68f9ea3^{commit}
07a361072378fb3ae116db86244372dbd68f9ea3
already have revision, skipping fetch
# git checkout -q -f -B kisskb 07a361072378fb3ae116db86244372dbd68f9ea3
# git clean -qxdf
# < git log -1
# commit 07a361072378fb3ae116db86244372dbd68f9ea3
# Author: Daniel Henrique Barboza <danielhb413@gmail.com>
# Date:   Tue Mar 23 17:50:56 2021 -0300
# 
#     powerpc/pseries/hotplug-cpu: Show 'last online CPU' error in dlpar_cpu_offline()
#     
#     One of the reasons that dlpar_cpu_offline can fail is when attempting to
#     offline the last online CPU of the kernel. This can be observed in a
#     pseries QEMU guest that has hotplugged CPUs. If the user offlines all
#     other CPUs of the guest, and a hotplugged CPU is now the last online
#     CPU, trying to reclaim it will fail.
#     
#     The current error message in this situation returns rc with -EBUSY and a
#     generic explanation, e.g.:
#     
#       pseries-hotplug-cpu: Failed to offline CPU PowerPC,POWER9, rc: -16
#     
#     EBUSY can be caused by other conditions, such as cpu_hotplug_disable
#     being true. Throwing a more specific error message for this case,
#     instead of just "Failed to offline CPU", makes it clearer that the error
#     is in fact a known error situation instead of other generic/unknown
#     cause.
#     
#     This patch adds a 'last online' check in dlpar_cpu_offline() to catch
#     the 'last online CPU' offline error, eturning a more informative error
#     message:
#     
#       pseries-hotplug-cpu: Unable to remove last online CPU PowerPC,POWER9
#     
#     Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#     Link: https://lore.kernel.org/r/20210323205056.52768-2-danielhb413@gmail.com
# < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version
# < git log --format=%s --max-count=1 07a361072378fb3ae116db86244372dbd68f9ea3
# < make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-next_44x_bluestone_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  44x/bluestone_defconfig
# < make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-next_44x_bluestone_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  help
# make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-next_44x_bluestone_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  olddefconfig
# make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-next_44x_bluestone_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  
/kisskb/src/block/genhd.c: In function 'diskstats_show':
/kisskb/src/block/genhd.c:1311:1: warning: the frame size of 1160 bytes is larger than 1024 bytes [-Wframe-larger-than=]
 }
 ^
Completed OK
# rm -rf /kisskb/build/powerpc-next_44x_bluestone_defconfig_powerpc-gcc4.9
# Build took: 0:00:30.909994