Re: [syzbot] [mm?] WARNING in lock_list_lru_of_memcg

[Yu Zhao]

On Fri, Dec 13, 2024 at 8:56 PM syzbot
<syzbot+38a0cbd267eff2d286ff@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    7cb1b4663150 Merge tag 'locking_urgent_for_v6.13_rc3' of g..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=16e96b30580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=fee25f93665c89ac
> dashboard link: https://syzkaller.appspot.com/bug?extid=38a0cbd267eff2d286ff
> compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
>
> Unfortunately, I don't have any reproducer for this issue yet.
>
> Downloadable assets:
> disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-7cb1b466.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/13e083329dab/vmlinux-7cb1b466.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/fe3847d08513/bzImage-7cb1b466.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+38a0cbd267eff2d286ff@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 80 at mm/list_lru.c:97 lock_list_lru_of_memcg+0x395/0x4e0 mm/list_lru.c:97
> Modules linked in:
> CPU: 0 UID: 0 PID: 80 Comm: kswapd0 Not tainted 6.13.0-rc2-syzkaller-00018-g7cb1b4663150 #0
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
> RIP: 0010:lock_list_lru_of_memcg+0x395/0x4e0 mm/list_lru.c:97
> Code: e9 22 fe ff ff e8 9b cc b6 ff 4c 8b 7c 24 10 45 84 f6 0f 84 40 ff ff ff e9 37 01 00 00 e8 83 cc b6 ff eb 05 e8 7c cc b6 ff 90 <0f> 0b 90 eb 97 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c 7a fd ff ff 48
> RSP: 0018:ffffc9000105e798 EFLAGS: 00010093
> RAX: ffffffff81e891c4 RBX: 0000000000000000 RCX: ffff88801f53a440
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: ffff888042e70054 R08: ffffffff81e89156 R09: 1ffffffff2032cae
> R10: dffffc0000000000 R11: fffffbfff2032caf R12: ffffffff81e88e5e
> R13: ffffffff9a3feb20 R14: 0000000000000000 R15: ffff888042e70000
> FS:  0000000000000000(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000020161000 CR3: 0000000032d12000 CR4: 0000000000352ef0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  <TASK>
>  list_lru_add+0x59/0x270 mm/list_lru.c:164
>  list_lru_add_obj+0x17b/0x250 mm/list_lru.c:187
>  workingset_update_node+0x1af/0x230 mm/workingset.c:634
>  xas_update lib/xarray.c:355 [inline]
>  update_node lib/xarray.c:758 [inline]
>  xas_store+0xb8f/0x1890 lib/xarray.c:845
>  page_cache_delete mm/filemap.c:149 [inline]
>  __filemap_remove_folio+0x4e9/0x670 mm/filemap.c:232
>  __remove_mapping+0x86f/0xad0 mm/vmscan.c:791
>  shrink_folio_list+0x30a6/0x5ca0 mm/vmscan.c:1467
>  evict_folios+0x3c86/0x5800 mm/vmscan.c:4593
>  try_to_shrink_lruvec+0x9a6/0xc70 mm/vmscan.c:4789
>  shrink_one+0x3b9/0x850 mm/vmscan.c:4834
>  shrink_many mm/vmscan.c:4897 [inline]
>  lru_gen_shrink_node mm/vmscan.c:4975 [inline]
>  shrink_node+0x37c5/0x3e50 mm/vmscan.c:5956
>  kswapd_shrink_node mm/vmscan.c:6785 [inline]
>  balance_pgdat mm/vmscan.c:6977 [inline]
>  kswapd+0x1ca9/0x36f0 mm/vmscan.c:7246
>  kthread+0x2f0/0x390 kernel/kthread.c:389
>  ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
>  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
>  </TASK>

This one seems to be related to "mm/list_lru: split the lock to
per-cgroup scope".

Kairui, can you please take a look? Thanks.

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