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Thu, 11 Dec 2025 12:24:38 -0800 (PST) Received: from localhost ([125.121.98.163]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-29ee9b37422sm33149375ad.15.2025.12.11.12.24.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Dec 2025 12:24:37 -0800 (PST) From: Yang Xin X-Google-Original-From: Yang Xin To: akpm@linux-foundation.org, mhocko@suse.com, rientjes@google.com, shakeel.butt@linux.dev Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Yang Xin Subject: [PATCH] mm/oom_kill: add sysctl_oom_dump_stack to control kernel stack dumping on OOM Date: Fri, 12 Dec 2025 04:24:33 +0800 Message-Id: <20251211202433.4495-1-redleaf@linux.alibaba.com> X-Mailer: git-send-email 2.30.2 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Most OOM kills triggered by user-space processes produce kernel stack traces that are not helpful for diagnosing the root cause. These traces usually just show the page fault handler or system call entry. Furthermore, dump_stack() can be expensive. It often runs with interrupts disabled or holds the console lock for a long time, potentially causing system latencies and preventing the system from responding to other events. This patch adds a new sysctl vm.oom_dump_stack to control this behavior. Writing '0' to /proc/sys/vm/oom_dump_stack suppresses the kernel stack dump during OOM kills, while '1' (the default) preserves the existing behavior. Signed-off-by: Yang Xin --- mm/oom_kill.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 5eb11fbba704..a51dbd2e6912 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -56,6 +56,7 @@ static int sysctl_panic_on_oom; static int sysctl_oom_kill_allocating_task; static int sysctl_oom_dump_tasks =3D 1; +static int sysctl_oom_dump_stack =3D 1; =20 /* * Serializes oom killer invocations (out_of_memory()) from all contexts to @@ -464,7 +465,9 @@ static void dump_header(struct oom_control *oc) if (!IS_ENABLED(CONFIG_COMPACTION) && oc->order) pr_warn("COMPACTION is disabled!!!\n"); =20 - dump_stack(); + if (sysctl_oom_dump_stack) + dump_stack(); + if (is_memcg_oom(oc)) mem_cgroup_print_oom_meminfo(oc->memcg); else { @@ -736,6 +739,13 @@ static const struct ctl_table vm_oom_kill_table[] =3D { .mode =3D 0644, .proc_handler =3D proc_dointvec, }, + { + .procname =3D "oom_dump_stack", + .data =3D &sysctl_oom_dump_stack, + .maxlen =3D sizeof(sysctl_oom_dump_stack), + .mode =3D 0644, + .proc_handler =3D proc_dointvec, + }, }; #endif =20 --=20 2.30.2