From nobody Mon Feb 9 17:23:13 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4831C001B0 for ; Thu, 10 Aug 2023 08:14:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234145AbjHJIOG (ORCPT ); Thu, 10 Aug 2023 04:14:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51144 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234089AbjHJIN7 (ORCPT ); Thu, 10 Aug 2023 04:13:59 -0400 Received: from mail-pf1-x42e.google.com (mail-pf1-x42e.google.com [IPv6:2607:f8b0:4864:20::42e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BA7EE2683 for ; Thu, 10 Aug 2023 01:13:36 -0700 (PDT) Received: by mail-pf1-x42e.google.com with SMTP id d2e1a72fcca58-686efb9ee3cso578541b3a.3 for ; Thu, 10 Aug 2023 01:13:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1691655216; x=1692260016; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=V+gOX8E32N7J0qn1e/cgbPAAdyKUl0JYooXv5sNbHuI=; b=OG7IuzB6CPOFfsV9wFrgnazb3f1VQrgIV5f+OOZdkCCvMJDzb3aV1VZFFlJjpUsXA3 +BP87n9CA/2IoiPk0nP0DzRB7WQ7FQy3RpzkGS3xJcTT6KV93ClOZg7CbgeULa7wj9ly Fr3KCTw83jY9eghkbiZB2yqiscmS6/rgT4aHFfjPPmngWuHbHqylqAWkCsuflY/r6XA/ u+1EJS1Q7o+TgHUDSY/Y9RXZe993prhItKrseX0iBXnPuQufH4ZiVy6hcumq/SQIiGp4 weiY7Tex+vf38O2Fi3m5cUUfZFvNYFueWFQFMKwYqa/fe7Wq4zxqt5ZSwFX0OfTK0l6P IEEw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691655216; x=1692260016; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=V+gOX8E32N7J0qn1e/cgbPAAdyKUl0JYooXv5sNbHuI=; b=ZFy+105Bz1Tc7JUwW59smB6b+rR2mt/1DQXnaqI6b50GAioaKK61BvlV3SUo7lUKyS lUfmPz/09yVq8XG88vftM5bV7TuUy3JNk52TTfw4DLG+xfABHzFaMC7r2cggcRHp5omg tdQfqnObMXTqpTHVd61cgj/NtPRHDKLrLQkiLt6jePBCvfLA/NrC7PNmPCO5TFpMT2U1 +y/yoSow1hTr15Y5qkJrT4OsARkbBnIOvnrKaSa4jc8lZv04GpOrjqu56zRqOfH8I2dk BQgZeHNT0C4IMxcMsmAOeADRO9/az15Txv8K8Ox6iVucRbHdKyma1Eq/+pfgtFXlhoZ0 z3og== X-Gm-Message-State: AOJu0Yyi5voIoxNMNK9P2NLv+YYo2E23LSGVZrfynAi1HaQhusj3MxK5 zLfU0sLXPWw7a8sAdOOG1ca9ag== X-Google-Smtp-Source: AGHT+IGtscS04wQJzOPzeNPixXB/Nvlgj5vG5uoIWZkaaoCuS2LHPKsrUQS+DTx+/kSMNoPf/s1uqQ== X-Received: by 2002:a17:903:246:b0:1b8:76ce:9d91 with SMTP id j6-20020a170903024600b001b876ce9d91mr1911030plh.1.1691655216226; Thu, 10 Aug 2023 01:13:36 -0700 (PDT) Received: from n37-019-243.byted.org ([180.184.51.40]) by smtp.gmail.com with ESMTPSA id x12-20020a170902ec8c00b001b1a2c14a4asm1019036plg.38.2023.08.10.01.13.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Aug 2023 01:13:35 -0700 (PDT) From: Chuyi Zhou To: hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, muchun.song@linux.dev Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, wuyun.abel@bytedance.com, robin.lu@bytedance.com, Chuyi Zhou Subject: [RFC PATCH v2 2/5] mm: Add policy_name to identify OOM policies Date: Thu, 10 Aug 2023 16:13:16 +0800 Message-Id: <20230810081319.65668-3-zhouchuyi@bytedance.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20230810081319.65668-1-zhouchuyi@bytedance.com> References: <20230810081319.65668-1-zhouchuyi@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This patch adds a new metadata policy_name in oom_control and report it in dump_header(), so we can know what has been the selection policy. In BPF program, we can call kfunc set_oom_policy_name to set the current user-defined policy name. The in-kernel policy_name is "default". Signed-off-by: Chuyi Zhou --- include/linux/oom.h | 7 +++++++ mm/oom_kill.c | 42 +++++++++++++++++++++++++++++++++++++++--- 2 files changed, 46 insertions(+), 3 deletions(-) diff --git a/include/linux/oom.h b/include/linux/oom.h index 7d0c9c48a0c5..69d0f2ec6ea6 100644 --- a/include/linux/oom.h +++ b/include/linux/oom.h @@ -22,6 +22,10 @@ enum oom_constraint { CONSTRAINT_MEMCG, }; =20 +enum { + POLICY_NAME_LEN =3D 16, +}; + /* * Details of the page allocation that triggered the oom killer that are u= sed to * determine what should be killed. @@ -52,6 +56,9 @@ struct oom_control { =20 /* Used to print the constraint info. */ enum oom_constraint constraint; + + /* Used to report the policy info. */ + char policy_name[POLICY_NAME_LEN]; }; =20 extern struct mutex oom_lock; diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 255c9ef1d808..3239dcdba4d7 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -443,6 +443,35 @@ static int dump_task(struct task_struct *p, void *arg) return 0; } =20 +__bpf_kfunc void set_oom_policy_name(struct oom_control *oc, const char *s= rc, size_t sz) +{ + memset(oc->policy_name, 0, sizeof(oc->policy_name)); + + if (sz > POLICY_NAME_LEN) + sz =3D POLICY_NAME_LEN; + + memcpy(oc->policy_name, src, sz); +} + +__diag_push(); +__diag_ignore_all("-Wmissing-prototypes", + "kfuncs which will be used in BPF programs"); + +__weak noinline void bpf_set_policy_name(struct oom_control *oc) +{ +} + +__diag_pop(); + +BTF_SET8_START(bpf_oom_policy_kfunc_ids) +BTF_ID_FLAGS(func, set_oom_policy_name) +BTF_SET8_END(bpf_oom_policy_kfunc_ids) + +static const struct btf_kfunc_id_set bpf_oom_policy_kfunc_set =3D { + .owner =3D THIS_MODULE, + .set =3D &bpf_oom_policy_kfunc_ids, +}; + /** * dump_tasks - dump current memory state of all system tasks * @oc: pointer to struct oom_control @@ -484,8 +513,8 @@ static void dump_oom_summary(struct oom_control *oc, st= ruct task_struct *victim) =20 static void dump_header(struct oom_control *oc, struct task_struct *p) { - pr_warn("%s invoked oom-killer: gfp_mask=3D%#x(%pGg), order=3D%d, oom_sco= re_adj=3D%hd\n", - current->comm, oc->gfp_mask, &oc->gfp_mask, oc->order, + pr_warn("%s invoked oom-killer: gfp_mask=3D%#x(%pGg), order=3D%d, policy_= name=3D%s, oom_score_adj=3D%hd\n", + current->comm, oc->gfp_mask, &oc->gfp_mask, oc->order, oc->policy_name, current->signal->oom_score_adj); if (!IS_ENABLED(CONFIG_COMPACTION) && oc->order) pr_warn("COMPACTION is disabled!!!\n"); @@ -775,8 +804,11 @@ static int __init oom_init(void) err =3D register_btf_fmodret_id_set(&oom_bpf_fmodret_set); if (err) pr_warn("error while registering oom fmodret entrypoints: %d", err); + err =3D register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, + &bpf_oom_policy_kfunc_set); + if (err) + pr_warn("error while registering oom kfunc entrypoints: %d", err); #endif - return 0; } subsys_initcall(oom_init) @@ -1196,6 +1228,10 @@ bool out_of_memory(struct oom_control *oc) return true; } =20 + set_oom_policy_name(oc, "default", sizeof("default")); + + bpf_set_policy_name(oc); + select_bad_process(oc); /* Found nothing?!?! */ if (!oc->chosen) { --=20 2.20.1