---------- Forwarded message --------- From: ying chen <[email protected]> Date: Tue, Mar 24, 2026 at 4:26 PM Subject: [BUG] rcu_tasks detected stalls in kcompactd during proactive compaction To: <[email protected]>, <[email protected]>, <[email protected]>, <[email protected]>
Hi all, I encountered an RCU tasks stall issue triggered by kcompactd0 on my system.Below are the details of the incident: Kernel Version：6.1.0-x vm.compaction_proactiveness = 20 CONFIG_PREEMPT_RCU=y [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] <TASK> [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+0xa0/0xa0 [Sun Mar 22 16:36:04 2026] ? kcompactd_do_work+0x2a0/0x2a0 [Sun Mar 22 16:36:04 2026] ? kthread+0xeb/0x120
