diff options
| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2025-03-14 13:36:11 +0000 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-03-21 22:03:11 -0700 |
| commit | fa23a338de93aa03eb0b6146a0440f5762309f85 (patch) | |
| tree | 2f7df593584bdb8ffe8ebfc87744d29a767d13af /mm | |
| parent | cb44821e1f524a5b8c05a738a40d572efd1ca430 (diff) | |
mm: separate folio_split_memcg_refs() from split_page_memcg()
Patch series "Minor memcg cleanups & prep for memdescs", v2.
Separate the handling of accounted folios and GFP_ACCOUNT pages for easier
to understand code. For more detail, see
https://lore.kernel.org/linux-mm/Z9LwTOudOlCGny3f@casper.infradead.org/
This patch (of 5):
Folios always use memcg_data to refer to the mem_cgroup while pages
allocated with GFP_ACCOUNT have a pointer to the obj_cgroup. Since the
caller already knows what it has, split the function into two and then we
don't need to check.
Move the assignment of split folio memcg_data to the point where we set up
the other parts of the new folio. That leaves folio_split_memcg_refs()
just handling the memcg accounting.
Link: https://lkml.kernel.org/r/20250314133617.138071-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20250314133617.138071-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/huge_memory.c | 16 | ||||
| -rw-r--r-- | mm/memcontrol.c | 17 |
2 files changed, 17 insertions, 16 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 10a86b681cf1..2a47682d1ab7 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3394,6 +3394,9 @@ static void __split_folio_to_order(struct folio *folio, int old_order, folio_set_young(new_folio); if (folio_test_idle(folio)) folio_set_idle(new_folio); +#ifdef CONFIG_MEMCG + new_folio->memcg_data = folio->memcg_data; +#endif folio_xchg_last_cpupid(new_folio, folio_last_cpupid(folio)); } @@ -3525,18 +3528,7 @@ static int __split_unmapped_folio(struct folio *folio, int new_order, } } - /* - * Reset any memcg data overlay in the tail pages. - * folio_nr_pages() is unreliable until prep_compound_page() - * was called again. - */ -#ifdef NR_PAGES_IN_LARGE_FOLIO - folio->_nr_pages = 0; -#endif - - - /* complete memcg works before add pages to LRU */ - split_page_memcg(&folio->page, old_order, split_order); + folio_split_memcg_refs(folio, old_order, split_order); split_page_owner(&folio->page, old_order, split_order); pgalloc_tag_split(folio, old_order, split_order); diff --git a/mm/memcontrol.c b/mm/memcontrol.c index ce57660bf5a2..f267b309b5b7 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3081,10 +3081,19 @@ void split_page_memcg(struct page *head, int old_order, int new_order) for (i = new_nr; i < old_nr; i += new_nr) folio_page(folio, i)->memcg_data = folio->memcg_data; - if (folio_memcg_kmem(folio)) - obj_cgroup_get_many(__folio_objcg(folio), old_nr / new_nr - 1); - else - css_get_many(&folio_memcg(folio)->css, old_nr / new_nr - 1); + obj_cgroup_get_many(__folio_objcg(folio), old_nr / new_nr - 1); +} + +void folio_split_memcg_refs(struct folio *folio, unsigned old_order, + unsigned new_order) +{ + unsigned new_refs; + + if (mem_cgroup_disabled() || !folio_memcg_charged(folio)) + return; + + new_refs = (1 << (old_order - new_order)) - 1; + css_get_many(&__folio_memcg(folio)->css, new_refs); } unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) |