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authorMina Almasry <almasrymina@google.com>2020-04-01 21:11:18 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-04-02 09:35:32 -0700
commit9808895e1a4416ffb9b3a0a121d81afc5a23c18b (patch)
treebe9a7aebf239636b70e358bb076fb42a62ee7a28 /mm/hugetlb_cgroup.c
parent1adc4d419aa282ed6d86f01935ce45d2215d8b8d (diff)
downloadlinux-9808895e1a4416ffb9b3a0a121d81afc5a23c18b.tar.bz2
mm/hugetlb_cgroup: fix hugetlb_cgroup migration
Commit c32300516047 ("hugetlb_cgroup: add interface for charge/uncharge hugetlb reservations") mistakingly doesn't handle the migration of *both* the reservation hugetlb_cgroup and the fault hugetlb_cgroup correctly. What should happen is that both cgroups shuold be queried from the old page, then both set to NULL on the old page, then both inserted into the new page. The mistake also creates the following warning: mm/hugetlb_cgroup.c: In function 'hugetlb_cgroup_migrate': mm/hugetlb_cgroup.c:777:25: warning: variable 'h_cg' set but not used [-Wunused-but-set-variable] struct hugetlb_cgroup *h_cg; ^~~~ Solution is to add the missing steps, namly setting the reservation hugetlb_cgroup to NULL on the old page, and setting the fault hugetlb_cgroup on the new page. Fixes: c32300516047 ("hugetlb_cgroup: add interface for charge/uncharge hugetlb reservations") Reported-by: Qian Cai <cai@lca.pw> Signed-off-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Sandipan Das <sandipan@linux.ibm.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Link: http://lkml.kernel.org/r/20200218194727.46995-1-almasrymina@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/hugetlb_cgroup.c')
-rw-r--r--mm/hugetlb_cgroup.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index 0aef0f34b80a..c5c8f8e2c2db 100644
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -797,8 +797,10 @@ void hugetlb_cgroup_migrate(struct page *oldhpage, struct page *newhpage)
h_cg = hugetlb_cgroup_from_page(oldhpage);
h_cg_rsvd = hugetlb_cgroup_from_page_rsvd(oldhpage);
set_hugetlb_cgroup(oldhpage, NULL);
+ set_hugetlb_cgroup_rsvd(oldhpage, NULL);
/* move the h_cg details to new cgroup */
+ set_hugetlb_cgroup(newhpage, h_cg);
set_hugetlb_cgroup_rsvd(newhpage, h_cg_rsvd);
list_move(&newhpage->lru, &h->hugepage_activelist);
spin_unlock(&hugetlb_lock);