I'm hitting below lockdep warning (essentially same with http://lkml.kernel.org/r/1518666178.6070.25.camel@xxxxxxxxx ) as of commit ba4dbdedd3edc279 ("Merge tag 'jfs-4.18' of git://github.com/kleikamp/linux-shaggy") on linux.git . I think that this became visible by commit 93781325da6e07af ("lockdep: fix fs_reclaim annotation") which went to 4.18-rc1. What should we do? [ 63.207781] [ 63.471926] ====================================================== [ 64.432812] WARNING: possible circular locking dependency detected [ 64.948272] 4.18.0-rc1+ #594 Tainted: G T [ 65.512546] ------------------------------------------------------ [ 65.519722] kswapd0/79 is trying to acquire lock: [ 65.525792] 00000000f3581fab (sb_internal){.+.+}, at: xfs_trans_alloc+0xe0/0x120 [xfs] [ 66.034497] [ 66.034497] but task is already holding lock: [ 66.661024] 00000000c7665973 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x0/0x30 [ 67.554480] [ 67.554480] which lock already depends on the new lock. [ 67.554480] [ 68.760085] [ 68.760085] the existing dependency chain (in reverse order) is: [ 69.258520] [ 69.258520] -> #1 (fs_reclaim){+.+.}: [ 69.623516] [ 69.623516] -> #0 (sb_internal){.+.+}: [ 70.152322] [ 70.152322] other info that might help us debug this: [ 70.152322] [ 70.164923] Possible unsafe locking scenario: [ 70.164923] [ 70.168174] CPU0 CPU1 [ 70.170441] ---- ---- [ 70.171827] lock(fs_reclaim); [ 70.172771] lock(sb_internal); [ 70.174447] lock(fs_reclaim); [ 70.176104] lock(sb_internal); [ 70.177062] [ 70.177062] *** DEADLOCK *** [ 70.177062] [ 70.178789] 1 lock held by kswapd0/79: [ 70.179893] #0: 00000000c7665973 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x0/0x30 [ 70.182213] [ 70.182213] stack backtrace: [ 70.184100] CPU: 2 PID: 79 Comm: kswapd0 Kdump: loaded Tainted: G T 4.18.0-rc1+ #594 [ 70.187320] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/19/2017 [ 70.191064] Call Trace: [ 70.192487] ? dump_stack+0x85/0xcb [ 70.194186] ? print_circular_bug.isra.37+0x1d7/0x1e4 [ 70.196343] ? __lock_acquire+0x126e/0x1330 [ 70.198232] ? lock_acquire+0x51/0x70 [ 70.199964] ? lock_acquire+0x51/0x70 [ 70.201735] ? xfs_trans_alloc+0xe0/0x120 [xfs] [ 70.203727] ? __sb_start_write+0x126/0x1a0 /* __preempt_count_add at ./arch/x86/include/asm/preempt.h:76 (inlined by) percpu_down_read_preempt_disable at ./include/linux/percpu-rwsem.h:38 (inlined by) percpu_down_read at ./include/linux/percpu-rwsem.h:59 (inlined by) __sb_start_write at fs/super.c:1403 */ [ 70.205618] ? xfs_trans_alloc+0xe0/0x120 [xfs] [ 70.207624] ? xfs_trans_alloc+0xe0/0x120 [xfs] /* sb_start_intwrite at ./include/linux/fs.h:1601 (inlined by) xfs_trans_alloc at fs/xfs/xfs_trans.c:259 */ [ 70.209599] ? xfs_iomap_write_allocate+0x1df/0x360 [xfs] /* xfs_iomap_write_allocate at fs/xfs/xfs_iomap.c:713 */ [ 70.211801] ? xfs_iunlock+0x6f/0x180 [xfs] [ 70.213657] ? xfs_map_blocks+0x1c6/0x240 [xfs] /* xfs_map_blocks at fs/xfs/xfs_aops.c:424 */ [ 70.215602] ? xfs_do_writepage+0x16d/0x7c0 [xfs] /* xfs_writepage_map at fs/xfs/xfs_aops.c:979 (inlined by) xfs_do_writepage at fs/xfs/xfs_aops.c:1162 */ [ 70.217585] ? find_held_lock+0x2d/0x90 [ 70.219308] ? clear_page_dirty_for_io+0x19d/0x470 [ 70.221291] ? xfs_vm_writepage+0x31/0x60 [xfs] /* xfs_vm_writepage at fs/xfs/xfs_aops.c:1181 */ [ 70.223201] ? pageout.isra.53+0x122/0x4f0 /* pageout at mm/vmscan.c:683 */ [ 70.224967] ? shrink_page_list+0xcc4/0x18f0 /* shrink_page_list at mm/vmscan.c:1200 */ [ 70.226771] ? shrink_inactive_list+0x2e8/0x5b0 /* spin_lock_irq at ./include/linux/spinlock.h:335 (inlined by) shrink_inactive_list at mm/vmscan.c:1787 */ [ 70.228624] ? shrink_node_memcg+0x367/0x780 /* shrink_list at mm/vmscan.c:2095 (inlined by) shrink_node_memcg at mm/vmscan.c:2358 */ [ 70.230433] ? __lock_is_held+0x55/0x90 [ 70.232167] ? shrink_node+0xc9/0x470 [ 70.233792] ? shrink_node+0xc9/0x470 /* shrink_node at mm/vmscan.c:2576 */ [ 70.235395] ? balance_pgdat+0x154/0x3a0 /* kswapd_shrink_node at mm/vmscan.c:3304 (inlined by) balance_pgdat at mm/vmscan.c:3405 */ [ 70.237070] ? finish_task_switch+0x93/0x290 [ 70.238861] ? kswapd+0x151/0x370 [ 70.240464] ? wait_woken+0xa0/0xa0 [ 70.242069] ? balance_pgdat+0x3a0/0x3a0 [ 70.243746] ? kthread+0x112/0x130 [ 70.245294] ? kthread_create_worker_on_cpu+0x70/0x70 [ 70.247281] ? ret_from_fork+0x24/0x30
