linux-kernel - Re: [PATCH 0/5 v1] mm, oom: Introduce per numa node oom for CONSTRAINT_MEMORY

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Date:   Thu, 12 May 2022 15:31:34 -0700
From:   Suren Baghdasaryan <surenb@...gle.com>
To:     Gang Li <ligang.bdlg@...edance.com>, Michal Hocko <mhocko@...e.com>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Muchun Song <songmuchun@...edance.com>, hca@...ux.ibm.com,
        gor@...ux.ibm.com, agordeev@...ux.ibm.com,
        borntraeger@...ux.ibm.com, svens@...ux.ibm.com,
        "Eric W. Biederman" <ebiederm@...ssion.com>,
        Kees Cook <keescook@...omium.org>,
        Al Viro <viro@...iv.linux.org.uk>,
        Steven Rostedt <rostedt@...dmis.org>,
        Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>, acme@...nel.org,
        mark.rutland@....com, alexander.shishkin@...ux.intel.com,
        jolsa@...nel.org, namhyung@...nel.org,
        David Hildenbrand <david@...hat.com>, imbrenda@...ux.ibm.com,
        apopple@...dia.com, Alexey Dobriyan <adobriyan@...il.com>,
        stephen.s.brennan@...cle.com, ohoono.kwon@...sung.com,
        haolee.swjtu@...il.com, Kalesh Singh <kaleshsingh@...gle.com>,
        zhengqi.arch@...edance.com, Peter Xu <peterx@...hat.com>,
        Yang Shi <shy828301@...il.com>,
        Colin Cross <ccross@...gle.com>, vincent.whitchurch@...s.com,
        Thomas Gleixner <tglx@...utronix.de>, bigeasy@...utronix.de,
        fenghua.yu@...el.com, linux-s390@...r.kernel.org,
        LKML <linux-kernel@...r.kernel.org>,
        linux-mm <linux-mm@...ck.org>,
        linux-fsdevel <linux-fsdevel@...r.kernel.org>,
        linux-perf-users@...r.kernel.org
Subject: Re: [PATCH 0/5 v1] mm, oom: Introduce per numa node oom for CONSTRAINT_MEMORY_POLICY

On Wed, May 11, 2022 at 9:47 PM Gang Li <ligang.bdlg@...edance.com> wrote:
>
> TLDR:
> If a mempolicy is in effect(oc->constraint == CONSTRAINT_MEMORY_POLICY), out_of_memory() will
> select victim on specific node to kill. So that kernel can avoid accidental killing on NUMA system.
>
> Problem:
> Before this patch series, oom will only kill the process with the highest memory usage.
> by selecting process with the highest oom_badness on the entire system to kill.
>
> This works fine on UMA system, but may have some accidental killing on NUMA system.
>
> As shown below, if process c.out is bind to Node1 and keep allocating pages from Node1,
> a.out will be killed first. But killing a.out did't free any mem on Node1, so c.out
> will be killed then.
>
> A lot of our AMD machines have 8 numa nodes. In these systems, there is a greater chance
> of triggering this problem.
>
> OOM before patches:
> ```
> Per-node process memory usage (in MBs)
> PID             Node 0        Node 1      Total
> ----------- ---------- ------------- ----------
> 3095 a.out     3073.34          0.11    3073.45(Killed first. Maximum memory consumption)
> 3199 b.out      501.35       1500.00    2001.35
> 3805 c.out        1.52 (grow)2248.00    2249.52(Killed then. Node1 is full)
> ----------- ---------- ------------- ----------
> Total          3576.21       3748.11    7324.31
> ```
>
> Solution:
> We store per node rss in mm_rss_stat for each process.
>
> If a page allocation with mempolicy in effect(oc->constraint == CONSTRAINT_MEMORY_POLICY)
> triger oom. We will calculate oom_badness with rss counter for the corresponding node. Then
> select the process with the highest oom_badness on the corresponding node to kill.
>
> OOM after patches:
> ```
> Per-node process memory usage (in MBs)
> PID             Node 0        Node 1     Total
> ----------- ---------- ------------- ----------
> 3095 a.out     3073.34          0.11    3073.45
> 3199 b.out      501.35       1500.00    2001.35
> 3805 c.out        1.52 (grow)2248.00    2249.52(killed)
> ----------- ---------- ------------- ----------
> Total          3576.21       3748.11    7324.31
> ```

You included lots of people but missed Michal Hocko. CC'ing him and
please include him in the future postings.

>
> Gang Li (5):
>   mm: add a new parameter `node` to `get/add/inc/dec_mm_counter`
>   mm: add numa_count field for rss_stat
>   mm: add numa fields for tracepoint rss_stat
>   mm: enable per numa node rss_stat count
>   mm, oom: enable per numa node oom for CONSTRAINT_MEMORY_POLICY
>
>  arch/s390/mm/pgtable.c        |   4 +-
>  fs/exec.c                     |   2 +-
>  fs/proc/base.c                |   6 +-
>  fs/proc/task_mmu.c            |  14 ++--
>  include/linux/mm.h            |  59 ++++++++++++-----
>  include/linux/mm_types_task.h |  16 +++++
>  include/linux/oom.h           |   2 +-
>  include/trace/events/kmem.h   |  27 ++++++--
>  kernel/events/uprobes.c       |   6 +-
>  kernel/fork.c                 |  70 +++++++++++++++++++-
>  mm/huge_memory.c              |  13 ++--
>  mm/khugepaged.c               |   4 +-
>  mm/ksm.c                      |   2 +-
>  mm/madvise.c                  |   2 +-
>  mm/memory.c                   | 116 ++++++++++++++++++++++++----------
>  mm/migrate.c                  |   2 +
>  mm/migrate_device.c           |   2 +-
>  mm/oom_kill.c                 |  59 ++++++++++++-----
>  mm/rmap.c                     |  16 ++---
>  mm/swapfile.c                 |   4 +-
>  mm/userfaultfd.c              |   2 +-
>  21 files changed, 317 insertions(+), 111 deletions(-)
>
> --
> 2.20.1
>