From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f199.google.com (mail-wr0-f199.google.com [209.85.128.199]) by kanga.kvack.org (Postfix) with ESMTP id B9FF06B0279 for ; Tue, 8 May 2018 08:47:23 -0400 (EDT) Received: by mail-wr0-f199.google.com with SMTP id k16-v6so21551062wrh.6 for ; Tue, 08 May 2018 05:47:23 -0700 (PDT) Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com. [67.231.145.42]) by mx.google.com with ESMTPS id 62-v6si365644edc.141.2018.05.08.05.47.21 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 08 May 2018 05:47:22 -0700 (PDT) From: Roman Gushchin Subject: [PATCH v2] mm: fix oom_kill event handling Date: Tue, 8 May 2018 13:46:37 +0100 Message-ID: <20180508124637.29984-1-guro@fb.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: kernel-team@fb.com Cc: Roman Gushchin , Johannes Weiner , Michal Hocko , Vladimir Davydov , Andrew Morton , Konstantin Khlebnikov , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org 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. Signed-off-by: Roman Gushchin Cc: Johannes Weiner Cc: Michal Hocko Cc: Vladimir Davydov Cc: Andrew Morton Cc: Konstantin Khlebnikov Cc: linux-kernel@vger.kernel.org Cc: cgroups@vger.kernel.org Cc: linux-mm@kvack.org --- 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 6cbea2f25a87..794475db7368 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -54,6 +54,7 @@ enum memcg_memory_event { MEMCG_HIGH, MEMCG_MAX, MEMCG_OOM, + MEMCG_OOM_KILL, MEMCG_SWAP_MAX, MEMCG_SWAP_FAIL, MEMCG_NR_MEMORY_EVENTS, @@ -721,11 +722,8 @@ static inline void count_memcg_event_mm(struct mm_struct *mm, rcu_read_lock(); memcg = rcu_dereference(mm->memcg); - 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(); } @@ -736,6 +734,21 @@ 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 = rcu_dereference(mm->memcg); + 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 @@ -757,6 +770,11 @@ 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 10973671e562..38717630305d 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3772,7 +3772,8 @@ 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; } @@ -5529,7 +5530,8 @@ 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 8f7d8dd99e5d..6b74142a1259 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -868,7 +868,7 @@ static void __oom_kill_process(struct task_struct *victim) /* 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 -- 2.14.3