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author | Konstantin Khlebnikov <khlebnikov@yandex-team.ru> | 2017-05-31 09:17:22 +1000 |
---|---|---|
committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2017-06-01 08:39:40 +1000 |
commit | 5cee3b514f43029dbef6528e0003d3e11e0eccd1 (patch) | |
tree | 32b45b93d65e018069fceb0865bcc0ee93bfe9ac | |
parent | f3dca277692b76a6135a99892b5755a9d87b8870 (diff) | |
download | linux-next-5cee3b514f43029dbef6528e0003d3e11e0eccd1.tar.gz |
mm/oom_kill: count global and memory cgroup oom kills
Show count of oom killer invocations in /proc/vmstat and count of
processes killed in memory cgroup in knob "memory.events" (in
memory.oom_control for v1 cgroup).
Also describe difference between "oom" and "oom_kill" in memory cgroup
documentation. Currently oom in memory cgroup kills tasks iff shortage
has happened inside page fault.
These counters helps in monitoring oom kills - for now
the only way is grepping for magic words in kernel log.
Link: http://lkml.kernel.org/r/149570810989.203600.9492483715840752937.stgit@buzz
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Roman Guschin <guroan@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r-- | Documentation/cgroup-v2.txt | 20 | ||||
-rw-r--r-- | include/linux/memcontrol.h | 5 | ||||
-rw-r--r-- | include/linux/vm_event_item.h | 1 | ||||
-rw-r--r-- | mm/memcontrol.c | 2 | ||||
-rw-r--r-- | mm/oom_kill.c | 5 | ||||
-rw-r--r-- | mm/vmstat.c | 1 |
6 files changed, 29 insertions, 5 deletions
diff --git a/Documentation/cgroup-v2.txt b/Documentation/cgroup-v2.txt index c16095a3fb70..a86f3cb88125 100644 --- a/Documentation/cgroup-v2.txt +++ b/Documentation/cgroup-v2.txt @@ -826,13 +826,25 @@ PAGE_SIZE multiple when read back. The number of times the cgroup's memory usage was about to go over the max boundary. If direct reclaim - fails to bring it down, the OOM killer is invoked. + fails to bring it down, the cgroup goes to OOM state. oom - The number of times the OOM killer has been invoked in - the cgroup. This may not exactly match the number of - processes killed but should generally be close. + The number of time the cgroup's memory usage was + reached the limit and allocation was about to fail. + + Depending on context result could be invocation of OOM + killer and retrying allocation or failing alloction. + + Failed allocation in its turn could be returned into + userspace as -ENOMEM or siletly ignored in cases like + disk readahead. For now OOM in memory cgroup kills + tasks iff shortage has happened inside page fault. + + oom_kill + + The number of processes belonging to this cgroup + killed by any kind of OOM killer. memory.stat diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index b2a5b1cd4e55..72d0853beb31 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -582,8 +582,11 @@ 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)) { this_cpu_inc(memcg->stat->events[idx]); + if (idx == OOM_KILL) + cgroup_file_notify(&memcg->events_file); + } rcu_read_unlock(); } #ifdef CONFIG_TRANSPARENT_HUGEPAGE diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h index d84ae90ccd5c..1707e0a7d943 100644 --- a/include/linux/vm_event_item.h +++ b/include/linux/vm_event_item.h @@ -41,6 +41,7 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, KSWAPD_LOW_WMARK_HIT_QUICKLY, KSWAPD_HIGH_WMARK_HIT_QUICKLY, PAGEOUTRUN, PGROTATED, DROP_PAGECACHE, DROP_SLAB, + OOM_KILL, #ifdef CONFIG_NUMA_BALANCING NUMA_PTE_UPDATES, NUMA_HUGE_PTE_UPDATES, diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 003816c0e100..8d50a2c00844 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3573,6 +3573,7 @@ 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)); return 0; } @@ -5164,6 +5165,7 @@ static int memory_events_show(struct seq_file *m, void *v) seq_printf(m, "high %lu\n", memcg_sum_events(memcg, MEMCG_HIGH)); seq_printf(m, "max %lu\n", memcg_sum_events(memcg, MEMCG_MAX)); seq_printf(m, "oom %lu\n", memcg_sum_events(memcg, MEMCG_OOM)); + seq_printf(m, "oom_kill %lu\n", memcg_sum_events(memcg, OOM_KILL)); return 0; } diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 04c9143a8625..dd30a045ef5b 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -876,6 +876,11 @@ static void oom_kill_process(struct oom_control *oc, const char *message) /* Get a reference to safely compare mm after task_unlock(victim) */ mm = victim->mm; mmgrab(mm); + + /* Raise event before sending signal: reaper must see this */ + count_vm_event(OOM_KILL); + mem_cgroup_count_vm_event(mm, OOM_KILL); + /* * We should send SIGKILL before setting TIF_MEMDIE in order to prevent * the OOM victim from depleting the memory reserves from the user diff --git a/mm/vmstat.c b/mm/vmstat.c index 6dae6b240b21..46281825c710 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -1018,6 +1018,7 @@ const char * const vmstat_text[] = { "drop_pagecache", "drop_slab", + "oom_kill", #ifdef CONFIG_NUMA_BALANCING "numa_pte_updates", |