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 <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Richard Chang <richardycc@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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 <jiwen7.qi@gmail.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
"zone_t" doesn't exist in current code base anymore, remove the
description of it.
Signed-off-by: I Hsin Cheng <richard120310@gmail.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250115070355.41769-1-richard120310@gmail.com
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 <mhocko@kernel.org>
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20230213154447.1631847-1-rppt@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Commit 5d8c5e430a ("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 <lukas.bulwahn@gmail.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Link: https://lore.kernel.org/r/20230215100808.9613-1-lukas.bulwahn@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Jon says:
> +See also :ref:`Page Reclaim <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: 5d8c5e430a ("docs/mm: Physical Memory: add structure, introduction and nodes description")
Suggested-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Link: https://lore.kernel.org/r/20230201094156.991542-2-rppt@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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 <bagasdotme@gmail.com>
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Link: https://lore.kernel.org/r/20230125192841.25342-2-rppt@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
so it will be consistent with code mm directory and with
Documentation/admin-guide/mm and won't be confused with virtual machines.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Tested-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: Wu XiangCheng <bobwxc@email.cn>
