[powerpc] Warning mm/slub.c:3246 during boot (next-20220210) w/ext4

[Ritesh Harjani]

On 22/02/10 06:57PM, Sachin Sant wrote:
> While booting 5.17.0-rc3-next-20220210 on Power following warning
> is seen:
>
> [   32.626501] EXT4-fs (sda2): re-mounted. Quota mode: none.
> [   32.627225] ------------[ cut here ]------------
> [   32.627236] WARNING: CPU: 27 PID: 1084 at mm/slub.c:3246 kmem_cache_alloc+0x3b0/0x680
> [   32.627250] Modules linked in: ext4 mbcache jbd2 sd_mod t10_pi sg ipr tg3 libata ptp pps_core fuse
> [   32.627273] CPU: 27 PID: 1084 Comm: kworker/u161:0 Not tainted 5.17.0-rc3-next-20220210 #17
> [   32.627283] NIP:  c000000000444df0 LR: c008000007fe6b44 CTR: c000000000444a40
> [   32.627291] REGS: c000000052393480 TRAP: 0700   Not tainted  (5.17.0-rc3-next-20220210)
> [   32.627298] MSR:  9000000000029033 <SF,HV,EE,ME,IR,DR,RI,LE>  CR: 44002822  XER: 20000000
> [   32.627316] CFAR: c000000000444a6c IRQMASK: 0
> [   32.627316] GPR00: c008000007fe6b44 c000000052393720 c000000002a06b00 c000000059660200
> [   32.627316] GPR04: 0000000000000d40 0000000000000000 c00000004f735000 c000000050760618
> [   32.627316] GPR08: 0000000000000001 0000000000080000 0000000000000038 c008000007fe7a70
> [   32.627316] GPR12: c000000000444a40 c0000007fffe1a80 c00000000017a6b8 0000000000000000
> [   32.627316] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> [   32.627316] GPR20: 0000000000000041 c000000052393b78 c000000052393a88 0000000000000338
> [   32.627316] GPR24: c0080000089706d8 c0080000089706d8 c00000004f735000 c008000008014a98
> [   32.627316] GPR28: 0000000000008d40 0000000000000000 0000000000400000 0000000000000100
> [   32.627398] NIP [c000000000444df0] kmem_cache_alloc+0x3b0/0x680
> [   32.627406] LR [c008000007fe6b44] jbd2_journal_add_journal_head+0x13c/0x2b8 [jbd2]
> [   32.627430] Call Trace:
> [   32.627433] [c000000052393720] [c008000007fd0e18] start_this_handle+0x530/0x6b0 [jbd2] (unreliable)
> [   32.627454] [c000000052393790] [0000000000000d40] 0xd40
> [   32.627462] [c000000052393820] [c008000007fd36d8] jbd2_journal_get_write_access+0x80/0x110 [jbd2]
> [   32.627482] [c000000052393860] [c0080000088c5640] __ext4_journal_get_write_access+0xb8/0x2d0 [ext4]
> [   32.627528] [c000000052393910] [c0080000088d69b8] ext4_file_open+0x2e0/0x430 [ext4]
> [   32.627571] [c0000000523939e0] [c000000000488cf0] do_dentry_open+0x170/0x4e0
> [   32.627582] [c000000052393a30] [c0000000004aabfc] path_openat+0xedc/0x1560
> [   32.627593] [c000000052393b30] [c0000000004ac634] do_filp_open+0xa4/0x130
> [   32.627602] [c000000052393c70] [c000000000499c8c] do_open_execat+0x9c/0x2f0
> [   32.627611] [c000000052393cc0] [c00000000049ad44] bprm_execve+0x184/0x7f0
> [   32.627620] [c000000052393d80] [c00000000049c6d8] kernel_execve+0x1a8/0x240
> [   32.627630] [c000000052393dd0] [c00000000017a838] call_usermodehelper_exec_async+0x188/0x2c0
> [   32.627642] [c000000052393e10] [c00000000000ce64] ret_from_kernel_thread+0x5c/0x64
> [   32.627652] Instruction dump:
> [   32.627657] e90d0030 7d49402a 394affff 7d49412a 4bbd1f79 60000000 eae10028 eb610048
> [   32.627672] 4bfffd80 60000000 60000000 60000000 <0fe00000> 7c0802a6 f8410018 fae10028
> [   32.627686] ---[ end trace 0000000000000000 ]—
>
> This WARN_ONCE was introduced by following commit:
>
> commit 120aa5e574796c9a3ef5f22cdb391747da997a26
>     mm: Check for SLAB_TYPESAFE_BY_RCU and __GFP_ZERO slab allocation
>
> The system has ext4 file system.

Yup, this is getting discussed in this thread [1] @ linux-ext4

[1]: https://lore.kernel.org/linux-ext4/20220210091648.w5wie3llqri5kfw3@quack3.lan/T/#m5f371e9910ee646e6361f484b2f12eab6aa47eeb

-ritesh