[PATCH v2 0/6] mm/page_owner: misc cleanups
From: Ye Liu
Date: Thu Jun 25 2026 - 22:46:10 EST
v2:
- Add cover letter (no code changes).
- Link:https://lore.kernel.org/all/20260623065234.31866-2-ye.liu@xxxxxxxxx/
This series collects a few cleanups for mm/page_owner.c that have been
accumulated while reading through the file. There is no functional
change -- the goal is to make the code easier to read and maintain.
Patch 1 consolidates three identical PageBuddy skip blocks into a
single skip_buddy_pages() helper, eliminating the duplication and
keeping the lockless-read comment in one place.
Patch 2 replaces the -1 magic number used for "never migrated" with
a local MIGRATE_REASON_NONE define, making the intent explicit at
every use site.
Patch 3 hoists the CONFIG_MEMCG guard out of print_page_owner_memcg()'s
body so that the real implementation and the empty stub are two clearly
separate definitions, the common kernel idiom.
Patch 4 adds a missing \n to the count_threshold debugfs attribute
format string so that cat(1) output is properly terminated.
Patch 5 moves free_ts_nsec from the allocation summary line to the
free section in __dump_page_owner(), grouping it with free_pid and
free_tgid where it logically belongs. This also makes the dump
output consistent with print_page_owner().
Patch 6 drops the redundant page_owner_ prefix from file-scoped static
symbols (stack_fops, threshold_fops, etc.). Since they cannot collide
across translation units, the prefix carries no information.
The series is based on v6.17-rc1 and has been compile-tested with and
without CONFIG_MEMCG.
Ye Liu (6):
mm/page_owner: extract skip_buddy_pages() helper to unify buddy page
skipping
mm/page_owner: use MIGRATE_REASON_NONE instead of -1 for
last_migrate_reason
mm/page_owner: hoist CONFIG_MEMCG to function level for
print_page_owner_memcg()
mm/page_owner: add missing newline to count_threshold format string
mm/page_owner: move free_ts_nsec output to free section in
__dump_page_owner()
mm/page_owner: drop redundant page_owner prefix from static symbols
mm/page_owner.c | 121 +++++++++++++++++++++++++++---------------------
1 file changed, 67 insertions(+), 54 deletions(-)
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2.43.0