The patch titled Subject: mm: memcontrol: fix get_active_memcg return value has been added to the -mm tree. Its filename is mm-memcontrol-fix-get_active_memcg-return-value.patch
This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-memcontrol-fix-get_active_memcg... and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-memcontrol-fix-get_active_memcg...
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------------------------------------------------------ From: Muchun Song songmuchun@bytedance.com Subject: mm: memcontrol: fix get_active_memcg return value
We use a global percpu int_active_memcg variable to store the remote memcg when we are in the interrupt context. But get_active_memcg always return the current->active_memcg or root_mem_cgroup. The remote memcg (set in the interrupt context) is ignored. This is not what we want. So fix it.
Link: https://lkml.kernel.org/r/20210223091101.42150-1-songmuchun@bytedance.com Fixes: 37d5985c003d ("mm: kmem: prepare remote memcg charging infra for interrupt contexts") Signed-off-by: Muchun Song songmuchun@bytedance.com Reviewed-by: Shakeel Butt shakeelb@google.com Reviewed-by: Roman Gushchin guro@fb.com Cc: Johannes Weiner hannes@cmpxchg.org Cc: Michal Hocko mhocko@kernel.org Cc: Vladimir Davydov vdavydov.dev@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
mm/memcontrol.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-)
--- a/mm/memcontrol.c~mm-memcontrol-fix-get_active_memcg-return-value +++ a/mm/memcontrol.c @@ -1061,13 +1061,9 @@ static __always_inline struct mem_cgroup
rcu_read_lock(); memcg = active_memcg(); - if (memcg) { - /* current->active_memcg must hold a ref. */ - if (WARN_ON_ONCE(!css_tryget(&memcg->css))) - memcg = root_mem_cgroup; - else - memcg = current->active_memcg; - } + /* remote memcg must hold a ref. */ + if (memcg && WARN_ON_ONCE(!css_tryget(&memcg->css))) + memcg = root_mem_cgroup; rcu_read_unlock();
return memcg; _
Patches currently in -mm which might be from songmuchun@bytedance.com are
mm-memcontrol-optimize-per-lruvec-stats-counter-memory-usage.patch mm-memcontrol-fix-nr_anon_thps-accounting-in-charge-moving.patch mm-memcontrol-convert-nr_anon_thps-account-to-pages.patch mm-memcontrol-convert-nr_file_thps-account-to-pages.patch mm-memcontrol-convert-nr_shmem_thps-account-to-pages.patch mm-memcontrol-convert-nr_shmem_pmdmapped-account-to-pages.patch mm-memcontrol-convert-nr_file_pmdmapped-account-to-pages.patch mm-memcontrol-make-the-slab-calculation-consistent.patch mm-memcontrol-replace-the-loop-with-a-list_for_each_entry.patch mm-memcontrol-fix-swap-undercounting-in-cgroup2.patch mm-memcontrol-fix-get_active_memcg-return-value.patch hugetlb-convert-page_huge_active-hpagemigratable-flag-fix.patch