From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, bhe@redhat.com, david@redhat.com,
linux-mm@kvack.org, mhocko@kernel.org, mhocko@suse.com,
mm-commits@vger.kernel.org, n-horiguchi@ah.jp.nec.com,
osalvador@suse.de, richardw.yang@linux.intel.com,
robin.murphy@arm.com, torvalds@linux-foundation.org,
vamshi.k.sthambamkadi@gmail.com
Subject: [patch 050/127] mm/memory_hotplug: disable the functionality for 32b
Date: Thu, 04 Jun 2020 16:48:51 -0700 [thread overview]
Message-ID: <20200604234851.FvqR8M-jA%akpm@linux-foundation.org> (raw)
In-Reply-To: <20200604164523.e15f3177f4b69dcb4f2534a1@linux-foundation.org>
From: Michal Hocko <mhocko@kernel.org>
Subject: mm/memory_hotplug: disable the functionality for 32b
Memory hotlug is broken for 32b systems at least since c6f03e2903c9 ("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.
Link: http://lkml.kernel.org/r/20200218100532.GA4151@dhcp22.suse.cz
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206401
Signed-off-by: Michal Hocko <mhocko@suse.com>
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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/Kconfig | 1 +
1 file changed, 1 insertion(+)
--- a/mm/Kconfig~memory_hotplug-disable-the-functionality-for-32b
+++ a/mm/Kconfig
@@ -158,6 +158,7 @@ config MEMORY_HOTPLUG
bool "Allow for memory hot-add"
depends on SPARSEMEM || X86_64_ACPI_NUMA
depends on ARCH_ENABLE_MEMORY_HOTPLUG
+ depends on 64BIT || BROKEN
select NUMA_KEEP_MEMINFO if NUMA
config MEMORY_HOTPLUG_SPARSE
_
next prev parent reply other threads:[~2020-06-04 23:48 UTC|newest]
Thread overview: 146+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-04 23:45 incoming Andrew Morton
2020-06-04 23:45 ` [patch 001/127] kcov: cleanup debug messages Andrew Morton
2020-06-04 23:45 ` [patch 002/127] kcov: fix potential use-after-free in kcov_remote_start Andrew Morton
2020-06-04 23:45 ` [patch 003/127] kcov: move t->kcov assignments into kcov_start/stop Andrew Morton
2020-06-04 23:45 ` [patch 004/127] kcov: move t->kcov_sequence assignment Andrew Morton
2020-06-04 23:46 ` [patch 005/127] kcov: use t->kcov_mode as enabled indicator Andrew Morton
2020-06-04 23:46 ` [patch 006/127] kcov: collect coverage from interrupts Andrew Morton
2020-06-04 23:46 ` [patch 007/127] usb: core: kcov: collect coverage from usb complete callback Andrew Morton
2020-06-04 23:46 ` [patch 008/127] mm/util.c: remove the VM_WARN_ONCE for vm_committed_as underflow check Andrew Morton
2020-06-04 23:46 ` [patch 009/127] h8300: remove usage of __ARCH_USE_5LEVEL_HACK Andrew Morton
2020-06-04 23:46 ` [patch 010/127] arm: add support for folded p4d page tables Andrew Morton
2020-06-04 23:46 ` [patch 011/127] arm64: " Andrew Morton
2020-06-04 23:46 ` [patch 012/127] hexagon: remove __ARCH_USE_5LEVEL_HACK Andrew Morton
2020-06-04 23:46 ` [patch 013/127] ia64: add support for folded p4d page tables Andrew Morton
2020-06-04 23:46 ` [patch 014/127] nios2: " Andrew Morton
2020-06-04 23:46 ` [patch 015/127] openrisc: " Andrew Morton
2020-06-04 23:46 ` [patch 016/127] powerpc: " Andrew Morton
2020-06-04 23:46 ` [patch 017/127] sh: fault: modernize printing of kernel messages Andrew Morton
2020-06-04 23:46 ` [patch 018/127] sh: drop __pXd_offset() macros that duplicate pXd_index() ones Andrew Morton
2020-06-04 23:46 ` [patch 019/127] sh: add support for folded p4d page tables Andrew Morton
2020-06-04 23:47 ` [patch 020/127] unicore32: remove __ARCH_USE_5LEVEL_HACK Andrew Morton
2020-06-04 23:47 ` [patch 021/127] asm-generic: remove pgtable-nop4d-hack.h Andrew Morton
2020-06-04 23:47 ` [patch 022/127] mm: remove __ARCH_HAS_5LEVEL_HACK and include/asm-generic/5level-fixup.h Andrew Morton
2020-06-04 23:47 ` [patch 023/127] x86/mm: define mm_p4d_folded() Andrew Morton
2020-06-04 23:47 ` [patch 024/127] mm/debug: add tests validating architecture page table helpers Andrew Morton
2020-06-04 23:47 ` [patch 025/127] mm/vmalloc: fix a typo in comment Andrew Morton
2020-06-04 23:47 ` [patch 026/127] arch/kmap: remove BUG_ON() Andrew Morton
2020-06-04 23:47 ` [patch 027/127] arch/xtensa: move kmap build bug out of the way Andrew Morton
2020-06-04 23:47 ` [patch 028/127] arch/kmap: remove redundant arch specific kmaps Andrew Morton
2020-06-04 23:47 ` [patch 029/127] arch/kunmap: remove duplicate kunmap implementations Andrew Morton
2020-06-04 23:47 ` [patch 030/127] {x86,powerpc,microblaze}/kmap: move preempt disable Andrew Morton
2020-06-04 23:47 ` [patch 031/127] arch/kmap_atomic: consolidate duplicate code Andrew Morton
2020-06-04 23:47 ` [patch 032/127] arch/kunmap_atomic: " Andrew Morton
2020-06-04 23:47 ` [patch 033/127] arch/kmap: ensure kmap_prot visibility Andrew Morton
2020-06-04 23:47 ` [patch 034/127] arch/kmap: don't hard code kmap_prot values Andrew Morton
2020-06-04 23:47 ` [patch 035/127] arch/kmap: define kmap_atomic_prot() for all arch's Andrew Morton
2020-06-04 23:48 ` [patch 036/127] drm: remove drm specific kmap_atomic code Andrew Morton
2020-06-04 23:48 ` [patch 037/127] kmap: remove kmap_atomic_to_page() Andrew Morton
2020-06-04 23:48 ` [patch 038/127] parisc/kmap: remove duplicate kmap code Andrew Morton
2020-06-04 23:48 ` [patch 039/127] sparc: remove unnecessary includes Andrew Morton
2020-06-04 23:48 ` [patch 040/127] kmap: consolidate kmap_prot definitions Andrew Morton
2020-06-04 23:48 ` [patch 041/127] mm: add kvfree_sensitive() for freeing sensitive data objects Andrew Morton
2020-06-04 23:48 ` [patch 042/127] mm/memory_hotplug: refrain from adding memory into an impossible node Andrew Morton
2020-06-04 23:48 ` [patch 043/127] powerpc/pseries/hotplug-memory: stop checking is_mem_section_removable() Andrew Morton
2020-06-04 23:48 ` [patch 044/127] mm/memory_hotplug: remove is_mem_section_removable() Andrew Morton
2020-06-04 23:48 ` [patch 045/127] mm/memory_hotplug: set node_start_pfn of hotadded pgdat to 0 Andrew Morton
2020-06-04 23:48 ` [patch 046/127] mm/memory_hotplug: handle memblocks only with CONFIG_ARCH_KEEP_MEMBLOCK Andrew Morton
2020-06-04 23:48 ` [patch 047/127] mm/memory_hotplug: introduce add_memory_driver_managed() Andrew Morton
2020-06-04 23:48 ` [patch 048/127] kexec_file: don't place kexec images on IORESOURCE_MEM_DRIVER_MANAGED Andrew Morton
2020-06-04 23:48 ` [patch 049/127] device-dax: add memory via add_memory_driver_managed() Andrew Morton
2020-06-04 23:48 ` Andrew Morton [this message]
2020-06-04 23:48 ` [patch 051/127] mm: replace zero-length array with flexible-array member Andrew Morton
2020-06-04 23:48 ` [patch 052/127] mm/memory_hotplug: fix a typo in comment "recoreded"->"recorded" Andrew Morton
2020-06-04 23:49 ` [patch 053/127] mm: ksm: fix a typo in comment "alreaady"->"already" Andrew Morton
2020-06-04 23:49 ` [patch 054/127] mm: mmap: fix a typo in comment "compatbility"->"compatibility" Andrew Morton
2020-06-04 23:49 ` [patch 055/127] mm/hugetlb: fix a typos in comments Andrew Morton
2020-06-04 23:49 ` [patch 056/127] mm/vmsan: fix some typos in comment Andrew Morton
2020-06-04 23:49 ` [patch 057/127] mm/compaction: fix a typo in comment "pessemistic"->"pessimistic" Andrew Morton
2020-06-04 23:49 ` [patch 058/127] mm/memblock: fix a typo in comment "implict"->"implicit" Andrew Morton
2020-06-04 23:49 ` [patch 059/127] mm/list_lru: fix a typo in comment "numbesr"->"numbers" Andrew Morton
2020-06-04 23:49 ` [patch 060/127] mm/filemap: fix a typo in comment "unneccssary"->"unnecessary" Andrew Morton
2020-06-04 23:49 ` [patch 061/127] mm/frontswap: fix some typos in frontswap.c Andrew Morton
2020-06-04 23:49 ` [patch 062/127] mm, memcg: fix some typos in memcontrol.c Andrew Morton
2020-06-04 23:49 ` [patch 063/127] mm: fix a typo in comment "strucure"->"structure" Andrew Morton
2020-06-04 23:49 ` [patch 064/127] mm/slub: fix a typo in comment "disambiguiation"->"disambiguation" Andrew Morton
2020-06-04 23:49 ` [patch 065/127] mm/sparse: fix a typo in comment "convienence"->"convenience" Andrew Morton
2020-06-04 23:49 ` [patch 066/127] mm/page-writeback: fix a typo in comment "effictive"->"effective" Andrew Morton
2020-06-04 23:49 ` [patch 067/127] mm/memory: fix a typo in comment "attampt"->"attempt" Andrew Morton
2020-06-04 23:49 ` [patch 068/127] mm: use false for bool variable Andrew Morton
2020-06-04 23:49 ` [patch 069/127] include/linux/mm.h: return true in cpupid_pid_unset() Andrew Morton
2020-06-04 23:49 ` [patch 070/127] zcomp: Use ARRAY_SIZE() for backends list Andrew Morton
2020-06-04 23:49 ` [patch 071/127] proc: rename "catch" function argument Andrew Morton
2020-06-04 23:49 ` [patch 072/127] user.c: make uidhash_table static Andrew Morton
2020-06-04 23:50 ` [patch 073/127] get_maintainer: add email addresses from .yaml files Andrew Morton
2020-06-04 23:50 ` [patch 074/127] get_maintainer: fix unexpected behavior for path/to//file (double slashes) Andrew Morton
2020-06-04 23:50 ` [patch 075/127] lib/math: avoid trailing newline hidden in pr_fmt() Andrew Morton
2020-06-04 23:50 ` [patch 076/127] lib: Add might_fault() to strncpy_from_user Andrew Morton
2020-06-04 23:50 ` [patch 077/127] lib/test_lockup.c: make test_inode static Andrew Morton
2020-06-04 23:50 ` [patch 078/127] lib/zlib: remove outdated and incorrect pre-increment optimization Andrew Morton
2020-06-04 23:50 ` [patch 079/127] lib/percpu-refcount.c: use a more common logging style Andrew Morton
2020-06-04 23:50 ` [patch 080/127] lib/flex_proportions.c: cleanup __fprop_inc_percpu_max Andrew Morton
2020-06-04 23:50 ` [patch 081/127] lib: make a test module with set/clear bit Andrew Morton
2020-06-04 23:50 ` [patch 082/127] include/linux/bitops.h: avoid clang shift-count-overflow warnings Andrew Morton
2020-06-04 23:50 ` [patch 083/127] checkpatch: additional MAINTAINER section entry ordering checks Andrew Morton
2020-06-04 23:50 ` [patch 084/127] checkpatch: look for c99 comments in ctx_locate_comment Andrew Morton
2020-06-04 23:50 ` [patch 085/127] checkpatch: disallow --git and --file/--fix Andrew Morton
2020-06-04 23:50 ` [patch 086/127] checkpatch: use patch subject when reading from stdin Andrew Morton
2020-06-04 23:50 ` [patch 087/127] fs/binfmt_elf: remove redundant elf_map ifndef Andrew Morton
2020-06-04 23:50 ` [patch 088/127] elfnote: mark all .note sections SHF_ALLOC Andrew Morton
2020-06-04 23:50 ` [patch 089/127] init: allow distribution configuration of default init Andrew Morton
2020-06-04 23:50 ` [patch 090/127] fat: don't allow to mount if the FAT length == 0 Andrew Morton
2020-06-04 23:50 ` [patch 091/127] fat: improve the readahead for FAT entries Andrew Morton
2020-06-04 23:51 ` [patch 092/127] fs/seq_file.c: seq_read: Update pr_info_ratelimited Andrew Morton
2020-06-04 23:51 ` [patch 093/127] include/linux/seq_file.h: introduce DEFINE_SEQ_ATTRIBUTE() helper macro Andrew Morton
2020-06-04 23:51 ` [patch 094/127] mm/vmstat.c: convert to use DEFINE_SEQ_ATTRIBUTE macro Andrew Morton
2020-06-04 23:51 ` [patch 095/127] kernel/kprobes.c: " Andrew Morton
2020-06-04 23:51 ` [patch 096/127] exec: simplify the copy_strings_kernel calling convention Andrew Morton
2020-06-04 23:51 ` [patch 097/127] exec: open code copy_string_kernel Andrew Morton
2020-06-04 23:51 ` [patch 098/127] rapidio: avoid data race between file operation callbacks and mport_cdev_add() Andrew Morton
2020-06-04 23:51 ` [patch 099/127] rapidio: convert get_user_pages() --> pin_user_pages() Andrew Morton
2020-06-04 23:51 ` [patch 100/127] kernel/relay.c: handle alloc_percpu returning NULL in relay_open Andrew Morton
2020-06-04 23:51 ` [patch 101/127] kernel/relay.c: fix read_pos error when multiple readers Andrew Morton
2020-06-04 23:51 ` [patch 102/127] selftests/x86/pkeys: move selftests to arch-neutral directory Andrew Morton
2020-06-04 23:51 ` [patch 103/127] selftests/vm/pkeys: rename all references to pkru to a generic name Andrew Morton
2020-06-04 23:51 ` [patch 104/127] selftests/vm/pkeys: move generic definitions to header file Andrew Morton
2020-06-04 23:51 ` [patch 105/127] selftests/vm/pkeys: move some definitions to arch-specific header Andrew Morton
2020-06-04 23:51 ` [patch 106/127] selftests/vm/pkeys: make gcc check arguments of sigsafe_printf() Andrew Morton
2020-06-04 23:51 ` [patch 107/127] selftests: vm: pkeys: Use sane types for pkey register Andrew Morton
2020-06-04 23:51 ` [patch 108/127] selftests: vm: pkeys: add helpers for pkey bits Andrew Morton
2020-06-04 23:51 ` [patch 109/127] selftests/vm/pkeys: fix pkey_disable_clear() Andrew Morton
2020-06-04 23:52 ` [patch 110/127] selftests/vm/pkeys: fix assertion in pkey_disable_set/clear() Andrew Morton
2020-06-04 23:52 ` [patch 111/127] selftests/vm/pkeys: fix alloc_random_pkey() to make it really random Andrew Morton
2020-06-04 23:52 ` [patch 112/127] selftests: vm: pkeys: use the correct huge page size Andrew Morton
2020-06-04 23:52 ` [patch 113/127] selftests/vm/pkeys: introduce generic pkey abstractions Andrew Morton
2020-06-04 23:52 ` [patch 114/127] selftests/vm/pkeys: introduce powerpc support Andrew Morton
2020-06-04 23:52 ` [patch 115/127] selftests/vm/pkeys: fix number of reserved powerpc pkeys Andrew Morton
2020-06-04 23:52 ` [patch 116/127] selftests/vm/pkeys: fix assertion in test_pkey_alloc_exhaust() Andrew Morton
2020-06-04 23:52 ` [patch 117/127] selftests/vm/pkeys: improve checks to determine pkey support Andrew Morton
2020-06-04 23:52 ` [patch 118/127] selftests/vm/pkeys: associate key on a mapped page and detect access violation Andrew Morton
2020-06-04 23:52 ` [patch 119/127] selftests/vm/pkeys: associate key on a mapped page and detect write violation Andrew Morton
2020-06-04 23:52 ` [patch 120/127] selftests/vm/pkeys: detect write violation on a mapped access-denied-key page Andrew Morton
2020-06-04 23:52 ` [patch 121/127] selftests/vm/pkeys: introduce a sub-page allocator Andrew Morton
2020-06-04 23:52 ` [patch 122/127] selftests/vm/pkeys: test correct behaviour of pkey-0 Andrew Morton
2020-06-04 23:52 ` [patch 123/127] selftests/vm/pkeys: override access right definitions on powerpc Andrew Morton
2020-06-04 23:52 ` [patch 124/127] selftests: vm: pkeys: use the correct page size " Andrew Morton
2020-06-04 23:52 ` [patch 125/127] selftests: vm: pkeys: fix multilib builds for x86 Andrew Morton
2020-06-04 23:52 ` [patch 126/127] tools/testing/selftests/vm: remove duplicate headers Andrew Morton
2020-06-04 23:53 ` [patch 127/127] lib/ubsan.c: fix gcc-10 warnings Andrew Morton
2020-06-06 0:18 ` + lib-test-get_count_order-long-in-test_bitopsc-fix.patch added to -mm tree Andrew Morton
2020-06-06 0:28 ` + checkpatch-add-test-for-possible-misuse-of-is_enabled-without-config_.patch " Andrew Morton
2020-06-06 0:35 ` [to-be-updated] exec-change-uselib2-is_sreg-failure-to-eacces.patch removed from " Andrew Morton
2020-06-06 0:35 ` [to-be-updated] exec-relocate-s_isreg-check.patch " Andrew Morton
2020-06-06 0:35 ` [to-be-updated] exec-relocate-path_noexec-check.patch " Andrew Morton
2020-06-06 0:35 ` [to-be-updated] fs-include-fmode_exec-when-converting-flags-to-f_mode.patch " Andrew Morton
2020-06-06 0:39 ` + exec-change-uselib2-is_sreg-failure-to-eacces.patch added to " Andrew Morton
2020-06-06 0:40 ` + exec-move-s_isreg-check-earlier.patch " Andrew Morton
2020-06-06 0:40 ` + exec-move-path_noexec-check-earlier.patch " Andrew Morton
2020-06-06 0:53 ` + khugepaged-selftests-fix-timeout-condition-in-wait_for_scan.patch " Andrew Morton
2020-06-06 1:04 ` + scripts-spelling-add-a-few-more-typos.patch " Andrew Morton
2020-06-06 1:06 ` + mm-page_idlec-skip-offline-pages.patch " Andrew Morton
2020-06-07 23:41 ` + nilfs2-fix-null-pointer-dereference-at-nilfs_segctor_do_construct.patch " Andrew Morton
2020-06-07 23:53 ` + mm-consolidate-pgd_index-and-pgd_offset_k-definitions-fix-3.patch " Andrew Morton
2020-06-08 0:21 ` + tracing-kprobes-handle-mixed-kernel-userspace-probes-better-fix.patch " Andrew Morton
2020-06-08 0:50 ` + docs-mm-gup-pin_user_pagesrst-add-a-case-5-v2.patch " Andrew Morton
2020-06-08 0:57 ` + kcov-check-kcov_softirq-in-kcov_remote_stop.patch " Andrew Morton
2020-06-08 1:24 ` + lib-lz4-lz4_decompressc-document-deliberate-use-of.patch " Andrew Morton
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