From: Vasily Averin <vvs@virtuozzo.com> To: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org>, Vladimir Davydov <vdavydov.dev@gmail.com>, Andrew Morton <akpm@linux-foundation.org>, Roman Gushchin <guro@fb.com>, Uladzislau Rezki <urezki@gmail.com>, Vlastimil Babka <vbabka@suse.cz>, Shakeel Butt <shakeelb@google.com>, Mel Gorman <mgorman@techsingularity.net>, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel@openvz.org Subject: Re: [PATCH memcg 0/1] false global OOM triggered by memcg-limited task Date: Tue, 19 Oct 2021 13:30:06 +0300 [thread overview] Message-ID: <687bf489-f7a7-5604-25c5-0c1a09e0905b@virtuozzo.com> (raw) In-Reply-To: <YW6GoZhFUJc1uLYr@dhcp22.suse.cz> On 19.10.2021 11:49, Michal Hocko wrote: > On Tue 19-10-21 09:30:18, Vasily Averin wrote: > [...] >> With my patch ("memcg: prohibit unconditional exceeding the limit of dying tasks") try_charge_memcg() can fail: >> a) due to fatal signal >> b) when mem_cgroup_oom -> mem_cgroup_out_of_memory -> out_of_memory() returns false (when select_bad_process() found nothing) >> >> To handle a) we can follow to your suggestion and skip excution of out_of_memory() in pagefault_out_of memory() >> To handle b) we can go to retry: if mem_cgroup_oom() return OOM_FAILED. > How is b) possible without current being killed? Do we allow remote > charging? out_of_memory for memcg_oom select_bad_process mem_cgroup_scan_tasks oom_evaluate_task oom_badness /* * Do not even consider tasks which are explicitly marked oom * unkillable or have been already oom reaped or the are in * the middle of vfork */ adj = (long)p->signal->oom_score_adj; if (adj == OOM_SCORE_ADJ_MIN || test_bit(MMF_OOM_SKIP, &p->mm->flags) || in_vfork(p)) { task_unlock(p); return LONG_MIN; } This time we handle userspace page fault, so we cannot be kenrel thread, and cannot be in_vfork(). However task can be marked as oom unkillable, i.e. have p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN It can be set via oom_score_adj_write(). Thank you, Vasily Averin
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From: Vasily Averin <vvs-5HdwGun5lf+gSpxsJD1C4w@public.gmane.org> To: Michal Hocko <mhocko-IBi9RG/b67k@public.gmane.org> Cc: Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>, Vladimir Davydov <vdavydov.dev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>, Roman Gushchin <guro-b10kYP2dOMg@public.gmane.org>, Uladzislau Rezki <urezki-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Vlastimil Babka <vbabka-AlSwsSmVLrQ@public.gmane.org>, Shakeel Butt <shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>, Mel Gorman <mgorman-3eNAlZScCAx27rWaFMvyedHuzzzSOjJt@public.gmane.org>, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kernel-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org Subject: Re: [PATCH memcg 0/1] false global OOM triggered by memcg-limited task Date: Tue, 19 Oct 2021 13:30:06 +0300 [thread overview] Message-ID: <687bf489-f7a7-5604-25c5-0c1a09e0905b@virtuozzo.com> (raw) In-Reply-To: <YW6GoZhFUJc1uLYr-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org> On 19.10.2021 11:49, Michal Hocko wrote: > On Tue 19-10-21 09:30:18, Vasily Averin wrote: > [...] >> With my patch ("memcg: prohibit unconditional exceeding the limit of dying tasks") try_charge_memcg() can fail: >> a) due to fatal signal >> b) when mem_cgroup_oom -> mem_cgroup_out_of_memory -> out_of_memory() returns false (when select_bad_process() found nothing) >> >> To handle a) we can follow to your suggestion and skip excution of out_of_memory() in pagefault_out_of memory() >> To handle b) we can go to retry: if mem_cgroup_oom() return OOM_FAILED. > How is b) possible without current being killed? Do we allow remote > charging? out_of_memory for memcg_oom select_bad_process mem_cgroup_scan_tasks oom_evaluate_task oom_badness /* * Do not even consider tasks which are explicitly marked oom * unkillable or have been already oom reaped or the are in * the middle of vfork */ adj = (long)p->signal->oom_score_adj; if (adj == OOM_SCORE_ADJ_MIN || test_bit(MMF_OOM_SKIP, &p->mm->flags) || in_vfork(p)) { task_unlock(p); return LONG_MIN; } This time we handle userspace page fault, so we cannot be kenrel thread, and cannot be in_vfork(). However task can be marked as oom unkillable, i.e. have p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN It can be set via oom_score_adj_write(). Thank you, Vasily Averin
next prev parent reply other threads:[~2021-10-19 10:30 UTC|newest] Thread overview: 131+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-10-18 8:13 [PATCH memcg 0/1] false global OOM triggered by memcg-limited task Vasily Averin 2021-10-18 8:13 ` Vasily Averin 2021-10-18 9:04 ` Michal Hocko 2021-10-18 9:04 ` Michal Hocko 2021-10-18 10:05 ` Vasily Averin 2021-10-18 10:05 ` Vasily Averin 2021-10-18 10:12 ` Vasily Averin 2021-10-18 10:12 ` Vasily Averin 2021-10-18 11:53 ` Michal Hocko 2021-10-18 11:53 ` Michal Hocko [not found] ` <27dc0c49-a0d6-875b-49c6-0ef5c0cc3ac8@virtuozzo.com> 2021-10-18 12:27 ` Michal Hocko 2021-10-18 12:27 ` Michal Hocko 2021-10-18 15:07 ` Shakeel Butt 2021-10-18 15:07 ` Shakeel Butt 2021-10-18 16:51 ` Michal Hocko 2021-10-18 16:51 ` Michal Hocko 2021-10-18 17:13 ` Shakeel Butt 2021-10-18 18:52 ` Vasily Averin 2021-10-18 18:52 ` Vasily Averin 2021-10-18 19:18 ` Vasily Averin 2021-10-18 19:18 ` Vasily Averin 2021-10-19 5:34 ` Shakeel Butt 2021-10-19 5:34 ` Shakeel Butt 2021-10-19 5:33 ` Shakeel Butt 2021-10-19 5:33 ` Shakeel Butt 2021-10-19 6:42 ` Vasily Averin 2021-10-19 6:42 ` Vasily Averin 2021-10-19 8:47 ` Michal Hocko 2021-10-19 8:47 ` Michal Hocko 2021-10-19 6:30 ` Vasily Averin 2021-10-19 6:30 ` Vasily Averin 2021-10-19 8:49 ` Michal Hocko 2021-10-19 8:49 ` Michal Hocko 2021-10-19 10:30 ` Vasily Averin [this message] 2021-10-19 10:30 ` Vasily Averin 2021-10-19 11:54 ` Michal Hocko 2021-10-19 11:54 ` Michal Hocko 2021-10-19 12:04 ` Michal Hocko 2021-10-19 12:04 ` Michal Hocko 2021-10-19 13:26 ` Vasily Averin 2021-10-19 13:26 ` Vasily Averin 2021-10-19 14:13 ` Michal Hocko 2021-10-19 14:13 ` Michal Hocko 2021-10-19 14:19 ` Michal Hocko 2021-10-19 14:19 ` Michal Hocko 2021-10-19 19:09 ` Vasily Averin 2021-10-19 19:09 ` Vasily Averin 2021-10-20 8:07 ` [PATCH memcg v4] memcg: prohibit unconditional exceeding the limit of dying tasks Vasily Averin 2021-10-20 8:07 ` Vasily Averin 2021-10-20 8:43 ` Michal Hocko 2021-10-20 8:43 ` Michal Hocko 2021-10-20 12:11 ` [PATCH memcg RFC 0/3] " Vasily Averin 2021-10-20 12:11 ` Vasily Averin [not found] ` <cover.1634730787.git.vvs@virtuozzo.com> 2021-10-20 12:12 ` [PATCH memcg 1/3] mm: do not firce global OOM from inside " Vasily Averin 2021-10-20 12:12 ` Vasily Averin 2021-10-20 12:33 ` Michal Hocko 2021-10-20 12:33 ` Michal Hocko 2021-10-20 13:52 ` Vasily Averin 2021-10-20 13:52 ` Vasily Averin 2021-10-20 12:13 ` [PATCH memcg 2/3] memcg: remove charge forcinig for " Vasily Averin 2021-10-20 12:13 ` Vasily Averin 2021-10-20 12:41 ` Michal Hocko 2021-10-20 12:41 ` Michal Hocko 2021-10-20 14:21 ` Vasily Averin 2021-10-20 14:21 ` Vasily Averin 2021-10-20 14:57 ` Michal Hocko 2021-10-20 14:57 ` Michal Hocko 2021-10-20 15:20 ` Tetsuo Handa 2021-10-20 15:20 ` Tetsuo Handa 2021-10-21 10:03 ` Michal Hocko 2021-10-21 10:03 ` Michal Hocko 2021-10-20 12:14 ` [PATCH memcg 3/3] memcg: handle memcg oom failures Vasily Averin 2021-10-20 12:14 ` Vasily Averin 2021-10-20 13:02 ` Michal Hocko 2021-10-20 15:46 ` Vasily Averin 2021-10-20 15:46 ` Vasily Averin 2021-10-21 11:49 ` Michal Hocko 2021-10-21 11:49 ` Michal Hocko 2021-10-21 15:05 ` Vasily Averin 2021-10-21 15:05 ` Vasily Averin 2021-10-21 16:47 ` Michal Hocko 2021-10-21 16:47 ` Michal Hocko 2021-10-22 8:10 ` [PATCH memcg v2 0/2] memcg: prohibit unconditional exceeding the limit of dying tasks Vasily Averin 2021-10-22 8:10 ` Vasily Averin [not found] ` <cover.1634889066.git.vvs@virtuozzo.com> 2021-10-22 8:11 ` [PATCH memcg v2 1/2] mm, oom: do not trigger out_of_memory from the #PF Vasily Averin 2021-10-22 8:11 ` Vasily Averin 2021-10-22 8:55 ` Michal Hocko 2021-10-22 8:55 ` Michal Hocko 2021-10-22 8:11 ` [PATCH memcg v2 2/2] memcg: prohibit unconditional exceeding the limit of dying tasks Vasily Averin 2021-10-22 8:11 ` Vasily Averin 2021-10-22 9:10 ` Michal Hocko 2021-10-22 9:10 ` Michal Hocko 2021-10-23 13:18 ` [PATCH memcg v3 0/3] " Vasily Averin 2021-10-23 13:18 ` Vasily Averin [not found] ` <cover.1634994605.git.vvs@virtuozzo.com> 2021-10-23 13:19 ` [PATCH memcg v3 1/3] mm, oom: pagefault_out_of_memory: don't force global OOM for " Vasily Averin 2021-10-23 13:19 ` Vasily Averin 2021-10-25 9:27 ` Michal Hocko 2021-10-25 9:27 ` Michal Hocko 2021-10-23 13:20 ` [PATCH memcg v3 2/3] mm, oom: do not trigger out_of_memory from the #PF Vasily Averin 2021-10-23 13:20 ` Vasily Averin 2021-10-23 15:01 ` Tetsuo Handa 2021-10-23 15:01 ` Tetsuo Handa 2021-10-23 19:15 ` Vasily Averin 2021-10-25 8:04 ` Michal Hocko 2021-10-25 8:04 ` Michal Hocko 2021-10-26 13:56 ` Tetsuo Handa 2021-10-26 13:56 ` Tetsuo Handa 2021-10-26 14:07 ` Michal Hocko 2021-10-26 14:07 ` Michal Hocko 2021-10-25 9:34 ` Michal Hocko 2021-10-25 9:34 ` Michal Hocko 2021-10-23 13:20 ` [PATCH memcg v3 3/3] memcg: prohibit unconditional exceeding the limit of dying tasks Vasily Averin 2021-10-23 13:20 ` Vasily Averin 2021-10-25 9:36 ` Michal Hocko 2021-10-25 9:36 ` Michal Hocko 2021-10-27 22:36 ` Andrew Morton 2021-10-27 22:36 ` Andrew Morton 2021-10-28 7:22 ` Vasily Averin 2021-10-28 7:22 ` Vasily Averin 2021-10-29 7:46 ` Greg Kroah-Hartman 2021-10-29 7:46 ` Greg Kroah-Hartman 2021-10-29 7:58 ` Michal Hocko 2021-10-29 7:58 ` Michal Hocko 2021-11-12 23:48 ` [PATCH memcg v4] " kernel test robot 2021-11-26 4:32 ` kernel test robot 2021-10-21 8:03 ` [PATCH memcg 0/1] false global OOM triggered by memcg-limited task Vasily Averin 2021-10-21 8:03 ` Vasily Averin 2021-10-21 11:49 ` Michal Hocko 2021-10-21 11:49 ` Michal Hocko 2021-10-21 13:24 ` Vasily Averin 2021-10-21 13:24 ` Vasily Averin
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