linux.git/mm/memory_hotplug.c, branch v6.18.21

mm/memory_hotplug: activate node before adding new memory blocks

2025-10-03T23:42:43+00:00

The sysfs attributes for memory blocks require the node ID to be set and
initialized, so move the node activation before adding new memory blocks. 
This also has the nice side effect that the BUG_ON() can be converted into
a WARN_ON() as we now can handle registration errors.

Link: https://lkml.kernel.org/r/20250729064637.51662-3-hare@kernel.org
Fixes: b9ff036082cd ("mm/memory_hotplug.c: make add_memory_resource use __try_online_node")
Signed-off-by: Hannes Reinecke 
Acked-by: David Hildenbrand 
Acked-by: Oscar Salvador 
Reviewed-by: Donet Tom 
Signed-off-by: Andrew Morton

mm/memory_hotplug: fix typo 'esecially' -> 'especially'

2025-09-28T18:51:31+00:00

Link: https://lkml.kernel.org/r/20250918174528.90879-1-manish1588@gmail.com
Signed-off-by: Manish Kumar 
Signed-off-by: Andrew Morton

mm/memremap: remove unused get_dev_pagemap() parameter

2025-09-21T21:22:21+00:00

GUP no longer uses get_dev_pagemap().  As it was the only user of the
get_dev_pagemap() pgmap caching feature it can be removed.

Link: https://lkml.kernel.org/r/20250903225926.34702-2-apopple@nvidia.com
Signed-off-by: Alistair Popple 
Acked-by: David Hildenbrand 
Reviewed-by: Jason Gunthorpe 
Reviewed-by: Dan Williams 
Cc: John Hubbard 
Cc: Oscar Salvador 
Cc: Peter Xu 
Signed-off-by: Andrew Morton

mm/memory_hotplug: fix hwpoisoned large folio handling in do_migrate_range()

2025-09-04T00:10:35+00:00

In do_migrate_range(), the hwpoisoned folio may be large folio, which
can't be handled by unmap_poisoned_folio().

I can reproduce this issue in qemu after adding delay in memory_failure()

BUG: kernel NULL pointer dereference, address: 0000000000000000
Workqueue: kacpi_hotplug acpi_hotplug_work_fn
RIP: 0010:try_to_unmap_one+0x16a/0xfc0
  
  rmap_walk_anon+0xda/0x1f0
  try_to_unmap+0x78/0x80
  ? __pfx_try_to_unmap_one+0x10/0x10
  ? __pfx_folio_not_mapped+0x10/0x10
  ? __pfx_folio_lock_anon_vma_read+0x10/0x10
  unmap_poisoned_folio+0x60/0x140
  do_migrate_range+0x4d1/0x600
  ? slab_memory_callback+0x6a/0x190
  ? notifier_call_chain+0x56/0xb0
  offline_pages+0x3e6/0x460
  memory_subsys_offline+0x130/0x1f0
  device_offline+0xba/0x110
  acpi_bus_offline+0xb7/0x130
  acpi_scan_hot_remove+0x77/0x290
  acpi_device_hotplug+0x1e0/0x240
  acpi_hotplug_work_fn+0x1a/0x30
  process_one_work+0x186/0x340

Besides, do_migrate_range() may be called between memory_failure set
hwpoison flag and isolate the folio from lru, so remove WARN_ON(). In other
places, unmap_poisoned_folio() is called when the folio is isolated, obey
it in do_migrate_range() too.

[david@redhat.com: don't abort offlining, fixed typo, add comment]
Link: https://lkml.kernel.org/r/3c214dff-9649-4015-840f-10de0e03ebe4@redhat.com
Fixes: b15c87263a69 ("hwpoison, memory_hotplug: allow hwpoisoned pages to be offlined")
Signed-off-by: Jinjiang Tu 
Signed-off-by: David Hildenbrand 
Acked-by: Zi Yan 
Reviewed-by: Miaohe Lin 
Cc: Kefeng Wang 
Cc: Luis Chamberalin 
Cc: Matthew Wilcox (Oracle) 
Cc: Michal Hocko 
Cc: Oscar Salvador 
Cc: Pankaj Raghav 
Signed-off-by: Andrew Morton

mm: rename __PageMovable() to page_has_movable_ops()

2025-07-13T23:38:29+00:00

Let's make it clearer that we are talking about movable_ops pages.

While at it, convert a VM_BUG_ON to a VM_WARN_ON_ONCE_PAGE.

Link: https://lkml.kernel.org/r/20250704102524.326966-17-david@redhat.com
Signed-off-by: David Hildenbrand 
Reviewed-by: Zi Yan 
Reviewed-by: Lorenzo Stoakes 
Reviewed-by: Harry Yoo 
Cc: Alistair Popple 
Cc: Al Viro 
Cc: Arnd Bergmann 
Cc: Brendan Jackman 
Cc: Byungchul Park 
Cc: Chengming Zhou 
Cc: Christian Brauner 
Cc: Christophe Leroy 
Cc: Eugenio Pé rez 
Cc: Greg Kroah-Hartman 
Cc: Gregory Price 
Cc: "Huang, Ying" 
Cc: Jan Kara 
Cc: Jason Gunthorpe 
Cc: Jason Wang 
Cc: Jerrin Shaji George 
Cc: Johannes Weiner 
Cc: John Hubbard 
Cc: Jonathan Corbet 
Cc: Joshua Hahn 
Cc: Liam Howlett 
Cc: Madhavan Srinivasan 
Cc: Mathew Brost 
Cc: Matthew Wilcox (Oracle) 
Cc: Miaohe Lin 
Cc: Michael Ellerman 
Cc: "Michael S. Tsirkin" 
Cc: Michal Hocko 
Cc: Mike Rapoport 
Cc: Minchan Kim 
Cc: Naoya Horiguchi 
Cc: Nicholas Piggin 
Cc: Oscar Salvador 
Cc: Peter Xu 
Cc: Qi Zheng 
Cc: Rakie Kim 
Cc: Rik van Riel 
Cc: Sergey Senozhatsky 
Cc: Shakeel Butt 
Cc: Suren Baghdasaryan 
Cc: Vlastimil Babka 
Cc: Xuan Zhuo 
Cc: xu xin 
Signed-off-by: Andrew Morton

mm/page_isolation: remove migratetype parameter from more functions

2025-07-13T23:38:18+00:00

migratetype is no longer overwritten during pageblock isolation,
start_isolate_page_range(), has_unmovable_pages(), and
set_migratetype_isolate() no longer need which migratetype to restore
during isolation failure.

For has_unmoable_pages(), it needs to know if the isolation is for CMA
allocation, so adding PB_ISOLATE_MODE_CMA_ALLOC provide the information. 
At the same time change isolation flags to enum pb_isolate_mode
(PB_ISOLATE_MODE_MEM_OFFLINE, PB_ISOLATE_MODE_CMA_ALLOC,
PB_ISOLATE_MODE_OTHER).  Remove REPORT_FAILURE and check
PB_ISOLATE_MODE_MEM_OFFLINE, since only PB_ISOLATE_MODE_MEM_OFFLINE
reports isolation failures.

alloc_contig_range() no longer needs migratetype.  Replace it with a newly
defined acr_flags_t to tell if an allocation is for CMA.  So does
__alloc_contig_migrate_range().  Add ACR_FLAGS_NONE (set to 0) to indicate
ordinary allocations.

Link: https://lkml.kernel.org/r/20250617021115.2331563-7-ziy@nvidia.com
Signed-off-by: Zi Yan 
Reviewed-by: Vlastimil Babka 
Acked-by: David Hildenbrand 
Cc: Baolin Wang 
Cc: Brendan Jackman 
Cc: Johannes Weiner 
Cc: Kirill A. Shuemov 
Cc: Mel Gorman 
Cc: Michal Hocko 
Cc: Oscar Salvador 
Cc: Richard Chang 
Cc: Suren Baghdasaryan 
Signed-off-by: Andrew Morton

mm/page_isolation: remove migratetype from undo_isolate_page_range()

2025-07-13T23:38:18+00:00

Since migratetype is no longer overwritten during pageblock isolation,
undoing pageblock isolation no longer needs which migratetype to restore.

Link: https://lkml.kernel.org/r/20250617021115.2331563-6-ziy@nvidia.com
Signed-off-by: Zi Yan 
Acked-by: David Hildenbrand 
Reviewed-by: Vlastimil Babka 
Cc: Baolin Wang 
Cc: Brendan Jackman 
Cc: Johannes Weiner 
Cc: Kirill A. Shuemov 
Cc: Mel Gorman 
Cc: Michal Hocko 
Cc: Oscar Salvador 
Cc: Richard Chang 
Cc: Suren Baghdasaryan 
Signed-off-by: Andrew Morton

mm/page_alloc: add support for initializing pageblock as isolated

2025-07-13T23:38:17+00:00

MIGRATE_ISOLATE is a standalone bit, so a pageblock cannot be initialized
to just MIGRATE_ISOLATE.  Add init_pageblock_migratetype() to enable
initialize a pageblock with a migratetype and isolated.

Link: https://lkml.kernel.org/r/20250617021115.2331563-4-ziy@nvidia.com
Signed-off-by: Zi Yan 
Reviewed-by: Vlastimil Babka 
Acked-by: David Hildenbrand 
Cc: Baolin Wang 
Cc: Brendan Jackman 
Cc: Johannes Weiner 
Cc: Kirill A. Shuemov 
Cc: Mel Gorman 
Cc: Michal Hocko 
Cc: Oscar Salvador 
Cc: Richard Chang 
Cc: Suren Baghdasaryan 
Signed-off-by: Andrew Morton

mm/page_alloc: pageblock flags functions clean up

2025-07-13T23:38:17+00:00

Patch series "Make MIGRATE_ISOLATE a standalone bit", v10.

This patchset moves MIGRATE_ISOLATE to a standalone bit to avoid being
overwritten during pageblock isolation process.  Currently,
MIGRATE_ISOLATE is part of enum migratetype (in include/linux/mmzone.h),
thus, setting a pageblock to MIGRATE_ISOLATE overwrites its original
migratetype.  This causes pageblock migratetype loss during
alloc_contig_range() and memory offline, especially when the process fails
due to a failed pageblock isolation and the code tries to undo the
finished pageblock isolations.

In terms of performance for changing pageblock types, no performance
change is observed:

1. I used perf to collect stats of offlining and onlining all memory
   of a 40GB VM 10 times and see that get_pfnblock_flags_mask() and
   set_pfnblock_flags_mask() take about 0.12% and 0.02% of the whole
   process respectively with and without this patchset across 3 runs.

2. I used perf to collect stats of dd from /dev/random to a 40GB tmpfs
   file and find get_pfnblock_flags_mask() takes about 0.05% of the
   process with and without this patchset across 3 runs.


This patch (of 6):

No functional change is intended.

1. Add __NR_PAGEBLOCK_BITS for the number of pageblock flag bits and use
   roundup_pow_of_two(__NR_PAGEBLOCK_BITS) as NR_PAGEBLOCK_BITS to take
   right amount of bits for pageblock flags.
2. Rename PB_migrate_skip to PB_compact_skip.
3. Add {get,set,clear}_pfnblock_bit() to operate one a standalone bit,
   like PB_compact_skip.
3. Make {get,set}_pfnblock_flags_mask() internal functions and use
   {get,set}_pfnblock_migratetype() for pageblock migratetype operations.
4. Move pageblock flags common code to get_pfnblock_bitmap_bitidx().
3. Use MIGRATETYPE_MASK to get the migratetype of a pageblock from its
   flags.
4. Use PB_migrate_end in the definition of MIGRATETYPE_MASK instead of
   PB_migrate_bits.
5. Add a comment on is_migrate_cma_folio() to prevent one from changing it
   to use get_pageblock_migratetype() and causing issues.

Link: https://lkml.kernel.org/r/20250617021115.2331563-1-ziy@nvidia.com
Link: https://lkml.kernel.org/r/20250617021115.2331563-2-ziy@nvidia.com
Signed-off-by: Zi Yan 
Reviewed-by: Vlastimil Babka 
Acked-by: David Hildenbrand 
Cc: Baolin Wang 
Cc: Brendan Jackman 
Cc: Johannes Weiner 
Cc: Kirill A. Shuemov 
Cc: Mel Gorman 
Cc: Michal Hocko 
Cc: Oscar Salvador 
Cc: Richard Chang 
Cc: Suren Baghdasaryan 
Signed-off-by: Andrew Morton

mm,memory_hotplug: drop status_change_nid parameter from memory_notify

2025-07-13T23:38:17+00:00

There no users left of status_change_nid, so drop it from memory_notify
struct.

Link: https://lkml.kernel.org/r/20250616135158.450136-12-osalvador@suse.de
Signed-off-by: Oscar Salvador 
Suggested-by: David Hildenbrand 
Acked-by: David Hildenbrand 
Reviewed-by: Vlastimil Babka 
Cc: Harry Yoo 
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joanthan Cameron 
Cc: Rakie Kim 
Signed-off-by: Andrew Morton