diff options
| author | Suren Baghdasaryan <surenb@google.com> | 2025-09-15 14:27:56 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-09-21 14:22:31 -0700 |
| commit | 7ffc923e252ca89e58228adbdc500a9fdea43c38 (patch) | |
| tree | b2fe1570a0ee733b897cf1889f867c025c4442e9 /mm | |
| parent | 9e8a0bbb128ec9379ce271ccecdfb022c483da0b (diff) | |
| download | linux-7ffc923e252ca89e58228adbdc500a9fdea43c38.tar.gz | |
alloc_tag: avoid warnings when freeing non-compound "tail" pages
When freeing "tail" pages of a non-compount high-order page, we properly
subtract the allocation tag counters, however later when these pages are
released, alloc_tag_sub() will issue warnings because tags for these pages
are NULL.
This issue was originally anticipated by Vlastimil in his review [1] and
then recently reported by David. Prevent warnings by marking the tags
empty.
Link: https://lkml.kernel.org/r/20250915212756.3998938-4-surenb@google.com
Link: https://lore.kernel.org/all/6db0f0c8-81cb-4d04-9560-ba73d63db4b8@suse.cz/ [1]
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: David Wang <00107082@163.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Usama Arif <usamaarif642@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/page_alloc.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 6ff9f17d5f4ecc..cf38d499e0459b 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5240,9 +5240,16 @@ static void ___free_pages(struct page *page, unsigned int order, __free_frozen_pages(page, order, fpi_flags); else if (!head) { pgalloc_tag_sub_pages(tag, (1 << order) - 1); - while (order-- > 0) + while (order-- > 0) { + /* + * The "tail" pages of this non-compound high-order + * page will have no code tags, so to avoid warnings + * mark them as empty. + */ + clear_page_tag_ref(page + (1 << order)); __free_frozen_pages(page + (1 << order), order, fpi_flags); + } } } |