linux-stable/mm
Michal Hocko b59d02ed08 mm/memory_hotplug: disable the functionality for 32b
Memory hotlug is broken for 32b systems at least since c6f03e2903 ("mm,
memory_hotplug: remove zone restrictions") which has considerably reworked
how can be memory associated with movable/kernel zones.  The same is not
really trivial to achieve in 32b where only lowmem is the kernel zone.
While we can tweak this immediate problem around there are likely other
land mines hidden at other places.

It is also quite dubious that there is a real usecase for the memory
hotplug on 32b in the first place.  Low memory is just too small to be
hotplugable (for hot add) and generally unusable for hotremove.  Adding
more memory to highmem is also dubious because it would increase the low
mem or vmalloc space pressure for memmaps.

Restrict the functionality to 64b systems.  This will help future
development to focus on usecases that have real life application.  We can
remove this restriction in future in presence of a real life usecase of
course but until then make it explicit that hotplug on 32b is broken and
requires a non trivial amount of work to fix.

Robin said:
 "32-bit Arm doesn't support memory hotplug, and as far as I'm aware
  there's little likelihood of it ever wanting to. FWIW it looks like
  SuperH is the only pure-32-bit architecture to have hotplug support at
  all"

Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>
Link: http://lkml.kernel.org/r/20200218100532.GA4151@dhcp22.suse.cz
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206401
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04 19:06:23 -07:00
..
kasan mm: remove __ARCH_HAS_5LEVEL_HACK and include/asm-generic/5level-fixup.h 2020-06-04 19:06:21 -07:00
backing-dev.c bdi: remove the name field in struct backing_dev_info 2020-05-09 16:15:13 -06:00
balloon_compaction.c mm/balloon_compaction: suppress allocation warnings 2019-09-04 07:42:01 -04:00
cleancache.c
cma.c mm: cma: NUMA node interface 2020-04-10 15:36:21 -07:00
cma.h
cma_debug.c mm/cma_debug.c: use DEFINE_DEBUGFS_ATTRIBUTE to define debugfs fops 2019-12-01 12:59:09 -08:00
compaction.c Merge branch 'akpm' (patches from Andrew) 2020-06-03 20:24:15 -07:00
debug.c mm, dump_page(): do not crash with invalid mapping pointer 2020-06-02 10:59:06 -07:00
debug_page_ref.c
debug_vm_pgtable.c mm/debug: add tests validating architecture page table helpers 2020-06-04 19:06:21 -07:00
dmapool.c mm/dmapool.c: micro-optimisation remove unnecessary branch 2020-04-07 10:43:42 -07:00
early_ioremap.c mm/early_ioremap.c: use %pa to print resource_size_t variables 2020-01-31 10:30:38 -08:00
fadvise.c mm: return void from various readahead functions 2020-06-02 10:59:06 -07:00
failslab.c
filemap.c mm: memcontrol: delete unused lrucare handling 2020-06-03 20:09:48 -07:00
frame_vector.c mm: untag user pointers in get_vaddr_frames 2019-09-25 17:51:41 -07:00
frontswap.c
gup.c mm, mempolicy: fix up gup usage in lookup_node 2020-06-03 20:09:49 -07:00
gup_benchmark.c mm/gup_benchmark: support pin_user_pages() and related calls 2020-04-02 09:35:27 -07:00
highmem.c mm, x86/mm: Untangle address space layout definitions from basic pgtable type definitions 2019-12-10 10:12:55 +01:00
hmm.c mm/hmm: remove the customizable pfn format from hmm_range_fault 2020-05-11 10:47:29 -03:00
huge_memory.c Merge branch 'akpm' (patches from Andrew) 2020-06-03 20:24:15 -07:00
hugetlb.c Merge branch 'akpm' (patches from Andrew) 2020-06-03 20:24:15 -07:00
hugetlb_cgroup.c mm: use fallthrough; 2020-04-07 10:43:41 -07:00
hwpoison-inject.c mm/hwpoison-inject: use DEFINE_DEBUGFS_ATTRIBUTE to define debugfs fops 2019-12-01 12:59:09 -08:00
init-mm.c mm/init-mm.c: include <linux/mman.h> for vm_committed_as_batch 2019-10-19 06:32:32 -04:00
internal.h mm/vmscan.c: change prototype for shrink_page_list 2020-06-03 20:09:47 -07:00
interval_tree.c
Kconfig mm/memory_hotplug: disable the functionality for 32b 2020-06-04 19:06:23 -07:00
Kconfig.debug mm: add DEBUG_WX support 2020-06-03 20:09:49 -07:00
khugepaged.c mm: fold and remove lru_cache_add_anon() and lru_cache_add_file() 2020-06-03 20:09:48 -07:00
kmemleak-test.c
kmemleak.c mm/kmemleak.c: use address-of operator on section symbols 2020-04-02 09:35:26 -07:00
ksm.c mm/ksm: fix NULL pointer dereference when KSM zero page is enabled 2020-04-21 11:11:55 -07:00
list_lru.c mm: use fallthrough; 2020-04-07 10:43:41 -07:00
maccess.c uaccess: Add strict non-pagefault kernel-space read function 2019-11-02 12:39:12 -07:00
madvise.c mm: check that mm is still valid in madvise() 2020-04-24 13:28:03 -07:00
Makefile mm/debug: add tests validating architecture page table helpers 2020-06-04 19:06:21 -07:00
mapping_dirty_helpers.c mm/mapping_dirty_helpers: update huge page-table entry callbacks 2020-04-02 09:35:29 -07:00
memblock.c mm: remove CONFIG_HAVE_MEMBLOCK_NODE_MAP option 2020-06-03 20:09:43 -07:00
memcontrol.c mm: base LRU balancing on an explicit cost model 2020-06-03 20:09:48 -07:00
memfd.c mm: page cache: store only head pages in i_pages 2019-09-24 15:54:08 -07:00
memory-failure.c ACPI updates for 5.8-rc1 2020-06-02 13:25:52 -07:00
memory.c mm: remove __ARCH_HAS_5LEVEL_HACK and include/asm-generic/5level-fixup.h 2020-06-04 19:06:21 -07:00
memory_hotplug.c mm/memory_hotplug: introduce add_memory_driver_managed() 2020-06-04 19:06:23 -07:00
mempolicy.c mm, mempolicy: fix up gup usage in lookup_node 2020-06-03 20:09:49 -07:00
mempool.c
memremap.c mm/memremap: set caching mode for PCI P2PDMA memory to WC 2020-04-10 15:36:21 -07:00
memtest.c
migrate.c mm: memcontrol: delete unused lrucare handling 2020-06-03 20:09:48 -07:00
mincore.c mm: pagewalk: add 'depth' parameter to pte_hole 2020-02-04 03:05:25 +00:00
mlock.c mm: untag user pointers passed to memory syscalls 2019-09-25 17:51:41 -07:00
mm_init.c mm/mm_init.c: report kasan-tag information stored in page->flags 2020-06-02 10:59:12 -07:00
mmap.c mm/vma: introduce VM_ACCESS_FLAGS 2020-04-10 15:36:21 -07:00
mmu_context.c
mmu_gather.c asm-generic/tlb: provide MMU_GATHER_TABLE_FREE 2020-02-04 03:05:26 +00:00
mmu_notifier.c mm/mmu_notifier: silence PROVE_RCU_LIST warnings 2020-03-21 18:56:06 -07:00
mmzone.c
mprotect.c mm/vma: introduce VM_ACCESS_FLAGS 2020-04-10 15:36:21 -07:00
mremap.c userfaultfd: fix remap event with MREMAP_DONTUNMAP 2020-05-14 10:00:35 -07:00
msync.c mm: untag user pointers passed to memory syscalls 2019-09-25 17:51:41 -07:00
nommu.c mm: remove vmalloc_sync_(un)mappings() 2020-06-02 10:59:12 -07:00
oom_kill.c mm/page_alloc: integrate classzone_idx and high_zoneidx 2020-06-03 20:09:44 -07:00
page-writeback.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-06-03 16:27:18 -07:00
page_alloc.c Merge branch 'akpm' (patches from Andrew) 2020-06-03 20:24:15 -07:00
page_counter.c mm, memcg: prevent memory.min load/store tearing 2020-04-02 09:35:29 -07:00
page_ext.c mm/page_ext.c: drop pfn_present() check when onlining 2020-04-07 10:43:40 -07:00
page_idle.c
page_io.c fs: Enable bmap() function to properly return errors 2020-02-03 08:05:37 -05:00
page_isolation.c mm: add function __putback_isolated_page 2020-04-07 10:43:38 -07:00
page_owner.c mm: rename gfpflags_to_migratetype to gfp_migratetype for same convention 2020-06-03 20:09:45 -07:00
page_poison.c mm/page_poison.c: fix a typo in a comment 2019-09-24 15:54:08 -07:00
page_reporting.c mm/page_reporting: add budget limit on how many pages can be reported per pass 2020-04-07 10:43:39 -07:00
page_reporting.h mm: introduce Reported pages 2020-04-07 10:43:38 -07:00
page_vma_mapped.c mm/page_vma_mapped.c: explicitly compare pfn for normal, hugetlbfs and THP page 2020-01-31 10:30:38 -08:00
pagewalk.c x86: mm: avoid allocating struct mm_struct on the stack 2020-02-04 03:05:25 +00:00
percpu-internal.h
percpu-km.c
percpu-stats.c percpu: update copyright emails to dennis@kernel.org 2020-04-01 10:09:12 -07:00
percpu-vm.c
percpu.c mm: remove the pgprot argument to __vmalloc 2020-06-02 10:59:11 -07:00
pgtable-generic.c mm/thp: rename pmd_mknotpresent() as pmd_mkinvalid() 2020-06-03 20:09:49 -07:00
process_vm_access.c mm: docs: Fix a comment in process_vm_rw_core 2020-03-25 10:04:01 -05:00
ptdump.c x86: mm: ptdump: calculate effective permissions correctly 2020-06-02 10:59:09 -07:00
readahead.c mm: use memalloc_nofs_save in readahead path 2020-06-02 10:59:07 -07:00
rmap.c mm: memcontrol: switch to native NR_ANON_THPS counter 2020-06-03 20:09:47 -07:00
rodata_test.c
shmem.c mm: fold and remove lru_cache_add_anon() and lru_cache_add_file() 2020-06-03 20:09:48 -07:00
shuffle.c mm: adjust shuffle code to allow for future coalescing 2020-04-07 10:43:38 -07:00
shuffle.h mm: adjust shuffle code to allow for future coalescing 2020-04-07 10:43:38 -07:00
slab.c mm/page_alloc: integrate classzone_idx and high_zoneidx 2020-06-03 20:09:44 -07:00
slab.h mm: kmem: rename (__)memcg_kmem_(un)charge_memcg() to __memcg_kmem_(un)charge() 2020-04-02 09:35:28 -07:00
slab_common.c usercopy: mark dma-kmalloc caches as usercopy caches 2020-06-02 10:59:06 -07:00
slob.c mm/sl[uo]b: export __kmalloc_track(_node)_caller 2020-03-26 14:45:51 +01:00
slub.c mm/page_alloc: integrate classzone_idx and high_zoneidx 2020-06-03 20:09:44 -07:00
sparse-vmemmap.c
sparse.c mm/sparse.c: move subsection_map related functions together 2020-04-07 10:43:40 -07:00
swap.c mm: swap: memcg: fix memcg stats for huge pages 2020-06-03 20:09:49 -07:00
swap_cgroup.c mm: memcontrol: make swap tracking an integral part of memory control 2020-06-03 20:09:48 -07:00
swap_slots.c mm/swap_slots.c: assign|reset cache slot by value directly 2020-04-02 09:35:27 -07:00
swap_state.c mm: vmscan: reclaim writepage is IO cost 2020-06-03 20:09:49 -07:00
swapfile.c mm: memcontrol: charge swapin pages on instantiation 2020-06-03 20:09:48 -07:00
truncate.c mm/thp: allow dropping THP from page cache 2019-10-19 06:32:33 -04:00
usercopy.c usercopy: Avoid HIGHMEM pfn warning 2019-09-17 15:20:17 -07:00
userfaultfd.c mm: memcontrol: delete unused lrucare handling 2020-06-03 20:09:48 -07:00
util.c mm: add kvfree_sensitive() for freeing sensitive data objects 2020-06-04 19:06:22 -07:00
vmacache.c
vmalloc.c mm/vmalloc: fix a typo in comment 2020-06-04 19:06:21 -07:00
vmpressure.c mm: vmpressure: use mem_cgroup_is_root API 2020-04-02 09:35:31 -07:00
vmscan.c mm: vmscan: limit the range of LRU type balancing 2020-06-03 20:09:49 -07:00
vmstat.c Merge branch 'akpm' (patches from Andrew) 2020-06-03 20:24:15 -07:00
workingset.c mm: vmscan: reclaim writepage is IO cost 2020-06-03 20:09:49 -07:00
z3fold.c mm/z3fold: silence kmemleak false positives of slots 2020-05-28 11:35:40 -07:00
zbud.c
zpool.c zpool: add malloc_support_movable to zpool_driver 2019-09-24 15:54:12 -07:00
zsmalloc.c mm: remove map_vm_range 2020-06-02 10:59:11 -07:00
zswap.c mm/zswap: allow setting default status, compressor and allocator in Kconfig 2020-04-07 10:43:41 -07:00