# git rev-parse -q --verify 06cfdca71d0b8b58f29f9e18f8cacc1172034971^{commit}
06cfdca71d0b8b58f29f9e18f8cacc1172034971
already have revision, skipping fetch
# git checkout -q -f -B kisskb 06cfdca71d0b8b58f29f9e18f8cacc1172034971
# git clean -qxdf
# < git log -1
# commit 06cfdca71d0b8b58f29f9e18f8cacc1172034971
# Author: Oliver O'Halloran <oohall@gmail.com>
# Date:   Fri Dec 7 02:17:14 2018 +1100
# 
#     powerpc/mm: Fallback to RAM if the altmap is unusable
#     
#     The "altmap" is used to provide a pool of memory that is reserved for
#     the vmemmap backing of hot-plugged memory. This is useful when adding
#     large amount of ZONE_DEVICE memory to a system with a limited amount of
#     normal memory.
#     
#     On ppc64 we use huge pages to map the vmemmap which requires the backing
#     storage to be contigious and aligned to the hugepage size. The altmap
#     implementation allows for the altmap provider to reserve a few PFNs at
#     the start of the range for it's own uses and when this occurs the
#     first chunk of the altmap is not usage for hugepage mappings. On hash
#     there is no sane way to fall back to a normal sized page mapping so we
#     fail the allocation. This results in memory hotplug failing with
#     ENOMEM when the new range doesn't fall into an existing vmemmap block.
#     
#     This patch handles this case by falling back to using system memory
#     rather than failing if we cannot allocate from the altmap. This
#     fallback should only ever be used for the first vmemmap block so it
#     should not cause excess memory consumption.
#     
#     Fixes: 7b73d978a5d0 ("mm: pass the vmem_altmap to vmemmap_populate")
#     Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
# < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version
# < git log --format=%s --max-count=1 06cfdca71d0b8b58f29f9e18f8cacc1172034971
# < make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pmac32_defconfig+KVM_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  pmac32_defconfig
# Added to kconfig CONFIG_VIRTUALIZATION=y
# Added to kconfig CONFIG_KVM=y
# Added to kconfig CONFIG_KVM_BOOK3S_32=m
# Added to kconfig 
# yes \n | make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pmac32_defconfig+KVM_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  oldconfig
yes: standard output: Broken pipe
# make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pmac32_defconfig+KVM_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  
In file included from /kisskb/src/sound/ppc/pmac.h:25:0,
                 from /kisskb/src/sound/ppc/awacs.c:29:
/kisskb/src/sound/ppc/awacs.c: In function 'snd_pmac_awacs_init':
/kisskb/src/include/sound/control.h:223:9: warning: 'speaker_vol' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return _snd_ctl_add_slave(master, slave, 0);
         ^
/kisskb/src/sound/ppc/awacs.c:886:36: note: 'speaker_vol' was declared here
  struct snd_kcontrol *master_vol, *speaker_vol;
                                    ^
INFO: Uncompressed kernel (size 0x8c493c) overlaps the address of the wrapper(0x400000)
INFO: Fixing the link_address of wrapper to (0x900000)
Completed OK
# rm -rf /kisskb/build/powerpc-fixes_pmac32_defconfig+KVM_powerpc-gcc5
# Build took: 0:00:51.204587