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Tue, 24 Mar 2026 01:27:02 -0700 (PDT) MIME-Version: 1.0 From: ying chen Date: Tue, 24 Mar 2026 16:26:51 +0800 X-Gm-Features: AQROBzDApd-lcJyoFG3o-8magek9CsQG1Q6TBlyspZ0oybgHMkr-1hBiED5WSOY Message-ID: Subject: [BUG] rcu_tasks detected stalls in kcompactd during proactive compaction To: linux-mm@kvack.org, linux-kernel@vger.org, paulmck@kernel.org, akpm@linux-foundation.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 585A740005 X-Stat-Signature: u8wdjcq84ewochb3re1uqrh998zirkce X-Rspam-User: X-Rspamd-Server: rspam10 X-HE-Tag: 1774340825-29435 X-HE-Meta: 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 uCmToQxL bLKX8/6HqUv8z5FZYgigzumUjNf4ZPrzlYPwU/zI6Swyvhk2HGx3ulbqLeYDde4u2Dc6pRaQO325WLQNDOieI5JfJLMZ//UbzoF7wJr7ZJkt2ns5qHfY4eVaOMGuOquKmnKtUp89sW56b9HSjZdUXmL+8YYUXGq4N0ZxsDJOzA6hlMTKHQj7roFGJ/o+oBtftgtCswWB2tZ6WJ31B3IMwxAVEq8BJSKF+dAEDjuAoKWZOa+udT4gQynUJqFXF23dWOF+VrKc45gJRfVMjotjEvz16orDE5/hN/7lUB6DqP9ucxZuZ8w/7Qyjod7rQS7IvPWAqfAacdYqaBQLmfpGqvCb7j3X7Oxfn7xFOpN+6/PLDZ/9EgbpK+T9Sz3DpRJ4SVUs2uhIddQ+9dcs2hcSyvMXxxcSyyj7Xfx70wKX2AsfatiEupmUkiYhpVpRPclldzVld8ZcHMBrGXj4hpeO5a/Yvlf5zo58VXe2CWxuYIpo0poXfIVrOeZiKqOyirRebUjKMoZjvOEOa0251SiU5+RDWIg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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