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Thu, 26 Mar 2026 19:47:59 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: ying chen Date: Fri, 27 Mar 2026 10:47:47 +0800 X-Gm-Features: AQROBzDUAyu9tpNSOVMlX-OjnQJ6xVte-6P4kxe-3-vWu77CbZkBxfC_Vmu4fvo Message-ID: Subject: Fwd: [BUG] rcu_tasks detected stalls in kcompactd during proactive compaction To: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, paulmck@kernel.org, frederic@kernel.org, quic_neeraju@quicinc.com, josh@joshtriplett.org, Steven Rostedt , mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, joel@joelfernandes.org, rcu@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 7D81CC0008 X-Stat-Signature: z4otc1c7qoo37erawmpi11mqh1ibi4ju X-Rspam-User: X-HE-Tag: 1774579681-561818 X-HE-Meta: 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 ZeBZwvwB 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: ---------- Forwarded message --------- From: ying chen Date: Tue, Mar 24, 2026 at 4:26=E2=80=AFPM Subject: [BUG] rcu_tasks detected stalls in kcompactd during proactive compaction To: , , , Hi all, I encountered an RCU tasks stall issue triggered by kcompactd0 on my system.Below are the details of the incident: Kernel Version=EF=BC=9A6.1.0-x vm.compaction_proactiveness =3D 20 CONFIG_PREEMPT_RCU=3Dy [Sun Mar 22 16:36:04 2026] INFO: rcu_tasks detected stalls on tasks: [Sun Mar 22 16:36:04 2026] 00000000fcafb4d6: .. nvcsw: 622963/622963 holdout: 1 idle_cpu: -1/1 [Sun Mar 22 16:36:04 2026] task:kcompactd0 state:R running task stack:0 pid:1943 [Sun Mar 22 16:36:04 2026] Call Trace: [Sun Mar 22 16:36:04 2026] [Sun Mar 22 16:36:04 2026] ? rmap_walk_anon+0x16b/0x330 [Sun Mar 22 16:36:04 2026] ? try_to_migrate+0x96/0x110 [Sun Mar 22 16:36:04 2026] ? try_to_unmap_one+0xd0/0xd0 [Sun Mar 22 16:36:04 2026] ? anon_vma_ctor+0x50/0x50 [Sun Mar 22 16:36:04 2026] ? folio_get_anon_vma+0x90/0x90 [Sun Mar 22 16:36:04 2026] ? invalid_mkclean_vma+0x20/0x20 [Sun Mar 22 16:36:04 2026] ? __unmap_and_move+0x21e/0x340 [Sun Mar 22 16:36:04 2026] ? free_unref_page+0x17d/0x1f0 [Sun Mar 22 16:36:04 2026] ? release_freepages+0xc0/0xc0 [Sun Mar 22 16:36:04 2026] ? release_freepages+0xc0/0xc0 [Sun Mar 22 16:36:04 2026] ? unmap_and_move+0xaa/0x4c0 [Sun Mar 22 16:36:04 2026] ? migrate_pages+0x3a9/0x790 [Sun Mar 22 16:36:04 2026] ? release_freepages+0xc0/0xc0 [Sun Mar 22 16:36:04 2026] ? isolate_migratepages+0x2a0/0x2a0 [Sun Mar 22 16:36:04 2026] ? compact_zone+0x310/0x5d0 [Sun Mar 22 16:36:04 2026] ? proactive_compact_node+0x88/0xc0 [Sun Mar 22 16:36:04 2026] ? kcompactd+0x365/0x3f0 [Sun Mar 22 16:36:04 2026] ? membarrier_register_private_expedited+0xa0/0x= a0 [Sun Mar 22 16:36:04 2026] ? kcompactd_do_work+0x2a0/0x2a0 [Sun Mar 22 16:36:04 2026] ? kthread+0xeb/0x120