powernv/memtrace is the only in-kernel user that rips out random memory it never added (doesn't own) in order to allocate memory without a linear mapping. Let's stop abusing memory hot(un)plug infrastructure for that - use alloc_contig_pages() for allocating memory and remove the linear mapping manually. The original idea was discussed in: https://lkml.kernel.org/r/48340e96-7e6b-736f-9e23-d3111b915b6e@xxxxxxxxxx I only tested allocations briefly via QEMU TCG - see patch #4 for more details. David Hildenbrand (4): powerpc/mm: factor out creating/removing linear mapping powerpc/mm: print warning in arch_remove_linear_mapping() powerpc/mm: remove linear mapping if __add_pages() fails in arch_add_memory() powernv/memtrace: don't abuse memory hot(un)plug infrastructure for memory allocations arch/powerpc/mm/mem.c | 48 +++++--- arch/powerpc/platforms/powernv/Kconfig | 8 +- arch/powerpc/platforms/powernv/memtrace.c | 134 ++++++++-------------- include/linux/memory_hotplug.h | 3 + 4 files changed, 86 insertions(+), 107 deletions(-) -- 2.26.2
