From: Roman Gushchin <guro@xxxxxx>
commit fe6bdfc8e1e131720abbe77a2eb990c94c9024cb upstream.
Commit e27be240df53 ("mm: memcg: make sure memory.events is uptodate
when waking pollers") converted most of memcg event counters to
per-memcg atomics, which made them less confusing for a user. The
"oom_kill" counter remained untouched, so now it behaves differently
than other counters (including "oom"). This adds nothing but confusion.
Let's fix this by adding the MEMCG_OOM_KILL event, and follow the
MEMCG_OOM approach.
This also removes a hack from count_memcg_event_mm(), introduced earlier
specially for the OOM_KILL counter.
[akpm@xxxxxxxxxxxxxxxxxxxx: fix for droppage of memcg-replace-mm-owner-with-mm-memcg.patch]
Link: http://lkml.kernel.org/r/20180508124637.29984-1-guro@xxxxxx
Signed-off-by: Roman Gushchin <guro@xxxxxx>
Acked-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
[fllinden@xxxxxxxxxx: backport to 4.14, minor contextual changes]
Signed-off-by: Frank van der Linden <fllinden@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
include/linux/memcontrol.h | 26 ++++++++++++++++++++++----
mm/memcontrol.c | 6 ++++--
mm/oom_kill.c | 2 +-
3 files changed, 27 insertions(+), 7 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index c7876eadd206..b5cd86e320ff 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -53,6 +53,7 @@ enum memcg_memory_event {
MEMCG_HIGH,
MEMCG_MAX,
MEMCG_OOM,
+ MEMCG_OOM_KILL,
MEMCG_NR_MEMORY_EVENTS,
};
@@ -706,11 +707,8 @@ static inline void count_memcg_event_mm(struct mm_struct *mm,
rcu_read_lock();
memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
- if (likely(memcg)) {
+ if (likely(memcg))
count_memcg_events(memcg, idx, 1);
- if (idx == OOM_KILL)
- cgroup_file_notify(&memcg->events_file);
- }
rcu_read_unlock();
}
@@ -721,6 +719,21 @@ static inline void memcg_memory_event(struct mem_cgroup *memcg,
cgroup_file_notify(&memcg->events_file);
}
+static inline void memcg_memory_event_mm(struct mm_struct *mm,
+ enum memcg_memory_event event)
+{
+ struct mem_cgroup *memcg;
+
+ if (mem_cgroup_disabled())
+ return;
+
+ rcu_read_lock();
+ memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
+ if (likely(memcg))
+ memcg_memory_event(memcg, event);
+ rcu_read_unlock();
+}
+
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
void mem_cgroup_split_huge_fixup(struct page *head);
#endif
@@ -742,6 +755,11 @@ static inline void memcg_memory_event(struct mem_cgroup *memcg,
{
}
+static inline void memcg_memory_event_mm(struct mm_struct *mm,
+ enum memcg_memory_event event)
+{
+}
+
static inline bool mem_cgroup_low(struct mem_cgroup *root,
struct mem_cgroup *memcg)
{
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 31972189a827..ef6d996a920a 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3648,7 +3648,8 @@ static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v)
seq_printf(sf, "oom_kill_disable %d\n", memcg->oom_kill_disable);
seq_printf(sf, "under_oom %d\n", (bool)memcg->under_oom);
- seq_printf(sf, "oom_kill %lu\n", memcg_sum_events(memcg, OOM_KILL));
+ seq_printf(sf, "oom_kill %lu\n",
+ atomic_long_read(&memcg->memory_events[MEMCG_OOM_KILL]));
return 0;
}
@@ -5320,7 +5321,8 @@ static int memory_events_show(struct seq_file *m, void *v)
atomic_long_read(&memcg->memory_events[MEMCG_MAX]));
seq_printf(m, "oom %lu\n",
atomic_long_read(&memcg->memory_events[MEMCG_OOM]));
- seq_printf(m, "oom_kill %lu\n", memcg_sum_events(memcg, OOM_KILL));
+ seq_printf(m, "oom_kill %lu\n",
+ atomic_long_read(&memcg->memory_events[MEMCG_OOM_KILL]));
return 0;
}
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 6482d743c5c8..6f1bed211122 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -917,7 +917,7 @@ static void oom_kill_process(struct oom_control *oc, const char *message)
/* Raise event before sending signal: task reaper must see this */
count_vm_event(OOM_KILL);
- count_memcg_event_mm(mm, OOM_KILL);
+ memcg_memory_event_mm(mm, MEMCG_OOM_KILL);
/*
* We should send SIGKILL before granting access to memory reserves
--
2.30.2
