From: Hugh Dickins <hughd@google.com>
Date: Sat, 19 Sep 2020 04:20:06 +0000 (-0700)
Subject: mm: migration of hugetlbfs page skip memcg
X-Git-Tag: v5.15~2891^2~11
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=a333e3e73b6648d3bd3ef6b971a59a6363bfcfc5;p=mirror_ubuntu-kernels.git

mm: migration of hugetlbfs page skip memcg

hugetlbfs pages do not participate in memcg: so although they do find most
of migrate_page_states() useful, it would be better if they did not call
into mem_cgroup_migrate() - where Qian Cai reported that LTP's
move_pages12 triggers the warning in Alex Shi's prospective commit
"mm/memcg: warning on !memcg after readahead page charged".

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxch.org>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Qian Cai <cai@lca.pw>
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2008301359460.5954@eggly.anvils
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/migrate.c b/mm/migrate.c
index 941b89383cf3..aecb1433cf3c 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -668,7 +668,8 @@ void migrate_page_states(struct page *newpage, struct page *page)
 
 	copy_page_owner(page, newpage);
 
-	mem_cgroup_migrate(page, newpage);
+	if (!PageHuge(page))
+		mem_cgroup_migrate(page, newpage);
 }
 EXPORT_SYMBOL(migrate_page_states);