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Thu, 12 Nov 2026 11:59:07 -0800 (PST) Received: from localhost ([153.61.198.252]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3b1aec3a903sm838062a91.8.2026.11.12.11.59.07 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 12 Nov 2026 11:59:07 -0800 (PST) X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Thu, 12 Nov 2026 19:59:06 +0000 Message-Id: Cc: "Andrii Nakryiko" , "Eduard Zingerman" , "Kumar Kartikeya Dwivedi" , "Martin KaFai Lau" , "Song Liu" , "Yonghong Song" , "Jiri Olsa" , "Emil Tsalapatis" , "Ihor Solodrai" , Subject: Re: [PATCH bpf] bpf: Fix soft lockup in fd_array_map_free() From: "Alexei Starovoitov" To: "Li Jinyue" , , "Alexei Starovoitov" , "Daniel Borkmann" X-Mailer: aerc 0.20.1-355-gf870624f6c37 References: <20261112122015.3356106-1-jinyue.li@linux.alibaba.com> In-Reply-To: <20261112122015.3356106-1-jinyue.li@linux.alibaba.com> On Thu Nov 12, 2026 at 12:20 PM UTC, Li Jinyue wrote: > fd_array_map_free() walks all map entries to assert that the map is > empty before its memory is freed. max_entries is not bounded, and the > free runs from the bpf_map_free_deferred work item, so with a large > max_entries the scan occupies the CPU for a long time without a > scheduling point: > > watchdog: BUG: soft lockup - CPU#1 stuck for 26s! [kworker/u8:5:8894] > Workqueue: events_unbound bpf_map_free_deferred > epc : fd_array_map_free+0x7c/0xea I don't think you root caused it correctly. pw-bot: cr