diff options
| author | Vladimir Davydov <vdavydov@virtuozzo.com> | 2016-08-12 00:33:03 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-08-12 01:58:13 +0200 |
| commit | 615d66c37c755c49ce022c9e5ac0875d27d2603d (patch) | |
| tree | a334291007e7fab20c84bb48010a0f5e6e7d7a5d /mm/memcontrol.c | |
| parent | mm: memcontrol: fix swap counter leak on swapout from offline cgroup (diff) | |
| download | linux-615d66c37c755c49ce022c9e5ac0875d27d2603d.tar.xz linux-615d66c37c755c49ce022c9e5ac0875d27d2603d.zip | |
mm: memcontrol: fix memcg id ref counter on swap charge move
Since commit 73f576c04b94 ("mm: memcontrol: fix cgroup creation failure
after many small jobs") swap entries do not pin memcg->css.refcnt
directly. Instead, they pin memcg->id.ref. So we should adjust the
reference counters accordingly when moving swap charges between cgroups.
Fixes: 73f576c04b941 ("mm: memcontrol: fix cgroup creation failure after many small jobs")
Link: http://lkml.kernel.org/r/9ce297c64954a42dc90b543bc76106c4a94f07e8.1470219853.git.vdavydov@virtuozzo.com
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org> [3.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
| -rw-r--r-- | mm/memcontrol.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 791b00ca4e8b..2ff0289ad061 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4077,9 +4077,9 @@ static struct cftype mem_cgroup_legacy_files[] = { static DEFINE_IDR(mem_cgroup_idr); -static void mem_cgroup_id_get(struct mem_cgroup *memcg) +static void mem_cgroup_id_get_many(struct mem_cgroup *memcg, unsigned int n) { - atomic_inc(&memcg->id.ref); + atomic_add(n, &memcg->id.ref); } static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg) @@ -4100,9 +4100,9 @@ static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg) return memcg; } -static void mem_cgroup_id_put(struct mem_cgroup *memcg) +static void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n) { - if (atomic_dec_and_test(&memcg->id.ref)) { + if (atomic_sub_and_test(n, &memcg->id.ref)) { idr_remove(&mem_cgroup_idr, memcg->id.id); memcg->id.id = 0; @@ -4111,6 +4111,16 @@ static void mem_cgroup_id_put(struct mem_cgroup *memcg) } } +static inline void mem_cgroup_id_get(struct mem_cgroup *memcg) +{ + mem_cgroup_id_get_many(memcg, 1); +} + +static inline void mem_cgroup_id_put(struct mem_cgroup *memcg) +{ + mem_cgroup_id_put_many(memcg, 1); +} + /** * mem_cgroup_from_id - look up a memcg from a memcg id * @id: the memcg id to look up @@ -4745,6 +4755,8 @@ static void __mem_cgroup_clear_mc(void) if (!mem_cgroup_is_root(mc.from)) page_counter_uncharge(&mc.from->memsw, mc.moved_swap); + mem_cgroup_id_put_many(mc.from, mc.moved_swap); + /* * we charged both to->memory and to->memsw, so we * should uncharge to->memory. @@ -4752,9 +4764,9 @@ static void __mem_cgroup_clear_mc(void) if (!mem_cgroup_is_root(mc.to)) page_counter_uncharge(&mc.to->memory, mc.moved_swap); - css_put_many(&mc.from->css, mc.moved_swap); + mem_cgroup_id_get_many(mc.to, mc.moved_swap); + css_put_many(&mc.to->css, mc.moved_swap); - /* we've already done css_get(mc.to) */ mc.moved_swap = 0; } memcg_oom_recover(from); |