linux-toradex.git/Documentation/mm/physical_memory.rst, branch v7.0-rc2

docs: update physical memory documentation by adding N_GENERIC_INITIATOR to enum node_states

2025-08-11T17:03:37+00:00

While reading physical_memory.rst, I noticed that N_GENERIC_INITIATOR has not been update
from the node_states list, even though it's already added in commit 894c26a1c274b8eafbb4b1dad67e70e51a106061.

Signed-off-by: Kim Tae Hyun 
Acked-by: Mike Rapoport (Microsoft) 
Signed-off-by: Jonathan Corbet 
Link: https://lore.kernel.org/r/20250802125801.10068-1-kimth0312@gmail.com

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

docs/mm: Physical Memory: Populate the "Zones" section

2025-03-22T05:03:14+00:00

Briefly describe what zones are and the fields of struct zone.

Link: https://lkml.kernel.org/r/20250315211317.27612-1-jiwen7.qi@gmail.com
Signed-off-by: Jiwen Qi 
Acked-by: Mike Rapoport (Microsoft) 
Cc: Bagas Sanjaya 
Cc: Jonathan Corbet 
Cc: Randy Dunlap 
Signed-off-by: Andrew Morton

docs/mm: Physical memory: Remove zone_t

2025-01-16T18:16:47+00:00

"zone_t" doesn't exist in current code base anymore, remove the
description of it.

Signed-off-by: I Hsin Cheng 
Reviewed-by: Randy Dunlap 
Signed-off-by: Jonathan Corbet 
Link: https://lore.kernel.org/r/20250115070355.41769-1-richard120310@gmail.com

docs/mm: Physical Memory: Fix grammar

2023-04-11T22:16:50+00:00

it's -> its
referenced to by -> referenced by

Signed-off-by: Kim Phillips 
Reviewed-by: Mike Rapoport (IBM) 
Link: https://lore.kernel.org/r/20230331165254.207526-1-kim.phillips@amd.com
Signed-off-by: Jonathan Corbet

docs/mm: Physical Memory: add example of interleaving nodes

2023-03-14T18:56:30+00:00

Add an example of memory layout with interleaving nodes where even memory
banks belong to node 0 and odd memory banks belong to node 1

Suggested-by: Michal Hocko 
Signed-off-by: Mike Rapoport (IBM) 
Reviewed-by: David Hildenbrand 
Link: https://lore.kernel.org/r/20230213154447.1631847-1-rppt@kernel.org
Signed-off-by: Jonathan Corbet

docs/mm: Physical Memory: fix a reference to a file that doesn't exist

2023-03-07T17:31:49+00:00

kbuild reports:

>> Warning: Documentation/mm/physical_memory.rst references a file that doesn't exist: Documentation/admin-guide/mm/memory_hotplug.rst

Fix the filename to be 'Documentation/admin-guide/mm/memory-hotplug.rst'.

Reported-by: kernel test robot 
Link: https://lore.kernel.org/oe-kbuild-all/202302231311.567PAoS2-lkp@intel.com/
Fixes: 353c7dd636ed ("docs/mm: Physical Memory: remove useless markup")
Signed-off-by: Mike Rapoport (IBM) 
Link: https://lore.kernel.org/r/20230224100306.2287696-1-rppt@kernel.org
Signed-off-by: Jonathan Corbet

docs/mm: Physical Memory: correct spelling in reference to CONFIG_PAGE_EXTENSION

2023-02-16T23:55:34+00:00

Commit 5d8c5e430a63 ("docs/mm: Physical Memory: add structure, introduction
and nodes description") slips in a minor spelling mistake for the config
PAGE_EXTENSION.

Correct the config name in the physical-memory documentation.

Signed-off-by: Lukas Bulwahn 
Acked-by: Mike Rapoport (IBM) 
Link: https://lore.kernel.org/r/20230215100808.9613-1-lukas.bulwahn@gmail.com
Signed-off-by: Jonathan Corbet

docs/mm: Physical Memory: remove useless markup

2023-02-02T17:18:04+00:00

Jon says:

  > +See also :ref:`Page Reclaim `.

  Can also just be "See also Documentation/mm/page_reclaim.rst".  The
  right things will happen in the HTML output, readers of the plain-text
  will know immediately where to go, and we don't have to add the label
  clutter.

Remove reference markup and unnecessary labes and use plain file names.

Fixes: 5d8c5e430a63 ("docs/mm: Physical Memory: add structure, introduction and nodes description")
Suggested-by: Jonathan Corbet 
Acked-by: Bagas Sanjaya 
Signed-off-by: Mike Rapoport (IBM) 
Link: https://lore.kernel.org/r/20230201094156.991542-2-rppt@kernel.org
Signed-off-by: Jonathan Corbet

docs/mm: Physical Memory: add structure, introduction and nodes description

2023-01-26T18:14:21+00:00

Add structure, introduction and Nodes section to Physical Memory
chapter.

As the new documentation references core-api/dma-api and mm/page_reclaim,
add page labels to those documents.

Reviewed-by: Bagas Sanjaya 
Reviewed-by: Lorenzo Stoakes 
Acked-by: Michal Hocko 
Acked-by: Vlastimil Babka 
Signed-off-by: Mike Rapoport (IBM) 
Link: https://lore.kernel.org/r/20230125192841.25342-2-rppt@kernel.org
Signed-off-by: Jonathan Corbet