| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.10 209/221] mm/memcg: fix 5.10 backport of splitting page memcg | Date | Mon, 29 Mar 2021 09:59:00 +0200 |
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From: Hugh Dickins <hughd@google.com>
The straight backport of 5.12's e1baddf8475b ("mm/memcg: set memcg when splitting page") works fine in 5.11, but turned out to be wrong for 5.10: because that relies on a separate flag, which must also be set for the memcg to be recognized and uncharged and cleared when freeing. Fix that.
Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- mm/memcontrol.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
--- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3274,13 +3274,17 @@ void obj_cgroup_uncharge(struct obj_cgro void split_page_memcg(struct page *head, unsigned int nr) { struct mem_cgroup *memcg = head->mem_cgroup; + int kmemcg = PageKmemcg(head); int i; if (mem_cgroup_disabled() || !memcg) return; - for (i = 1; i < nr; i++) + for (i = 1; i < nr; i++) { head[i].mem_cgroup = memcg; + if (kmemcg) + __SetPageKmemcg(head + i); + } css_get_many(&memcg->css, nr - 1); }
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