Commit fe6bdfc8 authored by Roman Gushchin's avatar Roman Gushchin Committed by Linus Torvalds
Browse files

mm: fix oom_kill event handling 

Commit e27be240 ("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@linux-foundation.org: fix for droppage of memcg-replace-mm-owner-with-mm-memcg.patch]
Link: http://lkml.kernel.org/r/20180508124637.29984-1-guro@fb.com


Signed-off-by: default avatarRoman Gushchin <guro@fb.com>
Acked-by: default avatarKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d7dc899a

include/linux/memcontrol.h

+22 −4
Original line number Diff line number Diff line
@@ -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(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();

}
@@ -735,6 +733,21 @@ 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
@@ -756,6 +769,11 @@ 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 enum mem_cgroup_protection mem_cgroup_protected(

	struct mem_cgroup *root, struct mem_cgroup *memcg)

{

mm/memcontrol.c

+4 −2
Original line number Diff line number Diff line
@@ -3550,7 +3550,8 @@ 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;

}
@@ -5239,7 +5240,8 @@ 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;

}

mm/oom_kill.c

+1 −1
Original line number Diff line number Diff line
@@ -913,7 +913,7 @@ 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

CRA Git | Maintained and supported by SUSTech CRA and CCSE