This series is based on the latest s390/features branch, which contains "s390/zcore: remove memmap device". [1] Looking into why we still create memblocks for stdnaby/hotplugged memory (via add_memory()), I discovered that we might not need ARCH_KEEP_MEMBLOCK on s390x after all. This is relevant in the context of virtio-mem, where we hotplug a lot of small memory blocks (and want to avoid managing unused metadata). But also for existing setups, it might help to free up some memory after boot. Compile-tested on s390x, pseries, arm64, i386, mips64, powernv, sh, and x86_64. [1] https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features v1 -> v2: - "mm/memblock: expose only miminal interface to add/walk physmem" -- Use inline function for __next_physmem_range -- Rewrite some comments RFC -> v1: - "s390/zcore: traverse resources instead of memblocks" has been replaced on s390/features by "s390/zcore: remove memmap devic" - Add "mm/memblock: expose only miminal interface to add/walk physmem" -- Sort out section mismatch errors when using physmem after boot without ARCH_KEEP_MEMBLOCK - "s390/mm: don't set ARCH_KEEP_MEMBLOCK" -- Rephrase description David Hildenbrand (2): mm/memblock: expose only miminal interface to add/walk physmem s390/mm: don't set ARCH_KEEP_MEMBLOCK arch/s390/Kconfig | 1 - arch/s390/kernel/crash_dump.c | 6 ++-- include/linux/memblock.h | 28 ++++++++++++++--- mm/memblock.c | 57 ++++++++++++++++++----------------- 4 files changed, 55 insertions(+), 37 deletions(-) -- 2.26.2