This is the backport of the following fixes for 4.19-stable: - d84f2f5a7552 ("drivers/base/node.c: simplify unregister_memory_block_under_nodes()") -- Turned out to not only be a cleanup but also a fix - 2c91f8fc6c99 ("mm/memory_hotplug: fix try_offline_node()") -- Automatic stable backport failed due to missing dependencies. - feee6b298916 ("mm/memory_hotplug: shrink zones when offlining memory") -- Was marked as stable 5.0+ due to the backport complexity,, but it's also relevant for 4.19/4.14. As I have to backport quite some cleanups already ... All tackle memory unplug issues, especially when memory was never onlined (or onlining failed), paired with memory unplug. When trying to access garbage memmaps we crash the kernel (e.g., because the derviced pgdat pointer is broken) To minimize manual code changes, I decided to pull in quite some cleanups. Still some manual code changes are necessary (indicated in the individual patches). Especially missing arm64 hot(un)plug, missing sub-section hotadd support, and missing unification of mm/hmm.c and kernel/memremap.c requires care. Due to: - 4e0d2e7ef14d ("mm, sparse: pass nid instead of pgdat to sparse_add_one_section()") I need: - afe9b36ca890 ("mm/memunmap: don't access uninitialized memmap in memunmap_pages()") Please note that: - 4c4b7f9ba948 ("mm/memory_hotplug: remove memory block devices before arch_remove_memory()") Makes big (e.g., 32TB) machines boot up slower (e.g., 2h vs 10m). There is a performance fix in linux-next, but it does not seem to classify as a fix for current RC / stable. I did quite some testing with hot(un)plug, onlining/offlining of memory blocks and memory-less/CPU-less NUMA nodes under x86_64 - the same set of tests I run against upstream on a fairly regular basis. I compile-tested on PowerPC, arm64, s390x, i386 and sh. I did not test any ZONE_DEVICE/HMM thingies. v1 -> v2: - Fix patch authors - Dropped "mm/memory_hotplug: make __remove_pages() and arch_remove_memory() never fail" -- Only creates a minor conflict in another patch - "mm/memory_hotplug: make remove_memory() take the device_hotplug_lock" -- Fix wrong upstream commit id - "mm/memory_hotplug: shrink zones when offlining memory" - "mm/memunmap: don't access uninitialized memmap in memunmap_pages()" -- Fix usage of wrong pfn CCing only some people to minimize noise. Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx> Cc: Baoquan He <bhe@xxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxx> Cc: Wei Yang <richard.weiyang@xxxxxxxxx> Aneesh Kumar K.V (2): powerpc/mm: Fix section mismatch warning mm/memunmap: don't access uninitialized memmap in memunmap_pages() Baoquan He (1): drivers/base/memory.c: clean up relics in function parameters Dan Carpenter (1): mm, memory_hotplug: update a comment in unregister_memory() Dan Williams (1): mm/hotplug: kill is_dev_zone() usage in __remove_pages() David Hildenbrand (15): mm/memory_hotplug: make remove_memory() take the device_hotplug_lock mm, memory_hotplug: add nid parameter to arch_remove_memory mm/memory_hotplug: make unregister_memory_section() never fail mm/memory_hotplug: make __remove_section() never fail mm/memory_hotplug: make __remove_pages() and arch_remove_memory() never fail s390x/mm: implement arch_remove_memory() mm/memory_hotplug: allow arch_remove_memory() without CONFIG_MEMORY_HOTREMOVE drivers/base/memory: pass a block_id to init_memory_block() mm/memory_hotplug: create memory block devices after arch_add_memory() mm/memory_hotplug: remove memory block devices before arch_remove_memory() mm/memory_hotplug: make unregister_memory_block_under_nodes() never fail mm/memory_hotplug: remove "zone" parameter from sparse_remove_one_section drivers/base/node.c: simplify unregister_memory_block_under_nodes() mm/memory_hotplug: fix try_offline_node() mm/memory_hotplug: shrink zones when offlining memory Oscar Salvador (1): mm/memory_hotplug: release memory resource after arch_remove_memory() Wei Yang (3): mm, sparse: drop pgdat_resize_lock in sparse_add/remove_one_section() mm, sparse: pass nid instead of pgdat to sparse_add_one_section() drivers/base/memory.c: remove an unnecessary check on NR_MEM_SECTIONS arch/ia64/mm/init.c | 15 +- arch/powerpc/mm/mem.c | 25 +-- arch/powerpc/platforms/powernv/memtrace.c | 2 +- .../platforms/pseries/hotplug-memory.c | 6 +- arch/s390/mm/init.c | 16 +- arch/sh/mm/init.c | 15 +- arch/x86/mm/init_32.c | 9 +- arch/x86/mm/init_64.c | 17 +- drivers/acpi/acpi_memhotplug.c | 2 +- drivers/base/memory.c | 203 +++++++++++------- drivers/base/node.c | 52 ++--- include/linux/memory.h | 8 +- include/linux/memory_hotplug.h | 22 +- include/linux/mmzone.h | 3 +- include/linux/node.h | 7 +- kernel/memremap.c | 12 +- mm/hmm.c | 8 +- mm/memory_hotplug.c | 166 +++++++------- mm/sparse.c | 27 +-- 19 files changed, 303 insertions(+), 312 deletions(-) -- 2.24.1