From: Roman Gushchin <guro@xxxxxx>
Subject: mm: fix oom_kill event handling
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>
---
include/linux/memcontrol.h | 26 ++++++++++++++++++++++----
mm/memcontrol.c | 6 ++++--
mm/oom_kill.c | 2 +-
3 files changed, 27 insertions(+), 7 deletions(-)
diff -puN include/linux/memcontrol.h~mm-fix-oom_kill-event-handling include/linux/memcontrol.h
--- a/include/linux/memcontrol.h~mm-fix-oom_kill-event-handling
+++ a/include/linux/memcontrol.h
@@ -53,6 +53,7 @@ enum memcg_memory_event {
MEMCG_HIGH,
MEMCG_MAX,
MEMCG_OOM,
+ MEMCG_OOM_KILL,
MEMCG_SWAP_MAX,
MEMCG_SWAP_FAIL,
MEMCG_NR_MEMORY_EVENTS,
@@ -720,11 +721,8 @@ static inline void count_memcg_event_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();
}
@@ -735,6 +733,21 @@ static inline void memcg_memory_event(st
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
@@ -756,6 +769,11 @@ static inline void memcg_memory_event(st
{
}
+static inline void memcg_memory_event_mm(struct mm_struct *mm,
+ enum memcg_memory_event event)
+{
+}
+
static inline enum mem_cgroup_protection mem_cgroup_protected(
struct mem_cgroup *root, struct mem_cgroup *memcg)
{
diff -puN mm/memcontrol.c~mm-fix-oom_kill-event-handling mm/memcontrol.c
--- a/mm/memcontrol.c~mm-fix-oom_kill-event-handling
+++ a/mm/memcontrol.c
@@ -3550,7 +3550,8 @@ static int mem_cgroup_oom_control_read(s
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;
}
@@ -5239,7 +5240,8 @@ static int memory_events_show(struct seq
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 -puN mm/oom_kill.c~mm-fix-oom_kill-event-handling mm/oom_kill.c
--- a/mm/oom_kill.c~mm-fix-oom_kill-event-handling
+++ a/mm/oom_kill.c
@@ -913,7 +913,7 @@ static void oom_kill_process(struct oom_
/* 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
_
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
