Re: [linux-next20260216]Warnings at mm/page_counter.c:60 at page_counter_cancel+0x110/0x134, CPU#24: kworker/24:3/1074770

[Shakeel Butt <shakeel.butt@linux.dev>]

On Wed, Feb 18, 2026 at 12:42:33PM +0100, Vlastimil Babka wrote:
> On 2/17/26 13:25, Carlos Maiolino wrote:
> > On Tue, Feb 17, 2026 at 04:54:06PM +0530, Venkat Rao Bagalkote wrote:
> >> Greetings!!!
> >> 
> >> I am observing below warnings, while running xfstests generic/332 test case.
> >> But I am not able to reproduce this consistently.
> >> 
> >> 
> >> Platform: IBM Power11 (pSeries LPAR), Radix MMU, LE, 64K pages
> >> Kernel: 6.19.0-next-20260216
> >> Tests: generic/332
> >> 
> >> local.config >>>
> >> [xfs_4k]
> >> export RECREATE_TEST_DEV=true
> >> export TEST_DEV=/dev/loop0
> >> export TEST_DIR=/mnt/test
> >> export SCRATCH_DEV=/dev/loop1
> >> export SCRATCH_MNT=/mnt/scratch
> >> export MKFS_OPTIONS="-b size=4096"
> >> export FSTYP=xfs
> >> export MOUNT_OPTIONS=""-
> >> 
> >> 
> >> 
> >> Attached is .config file used.
> >> 
> >> 
> >> Traces:
> >> 
> >> 
> >> [ 5152.507299] run fstests generic/332 at 2026-02-16 22:10:54
> >> [ 5152.792552] XFS (loop0): Mounting V5 Filesystem
> >> 93d6dd00-ca31-47bb-8170-254f04bcaa7f
> >> [ 5152.795270] XFS (loop0): Ending clean mount
> >> [ 5152.797551] ------------[ cut here ]------------
> >> [ 5152.797562] page_counter underflow: -1 nr_pages=58
> >> [ 5152.797586] WARNING: mm/page_counter.c:60 at
> >> page_counter_cancel+0x110/0x134, CPU#24: kworker/24:3/1074770
> >> [ 5152.797602] Modules linked in: dm_snapshot dm_bufio dm_flakey xfs loop
> >> dm_mod nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet
> >> nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat
> >> nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 bonding ip_set tls nf_tables
> >> rfkill sunrpc nfnetlink pseries_rng vmx_crypto dax_pmem fuse ext4 crc16
> >> mbcache jbd2 nd_pmem papr_scm sd_mod libnvdimm sg ibmvscsi ibmveth
> >> scsi_transport_srp pseries_wdt [last unloaded: scsi_debug]
> >> [ 5152.797712] CPU: 24 UID: 0 PID: 1074770 Comm: kworker/24:3 Kdump: loaded
> >> Not tainted 6.19.0-next-20260216 #1 PREEMPTLAZY
> >> [ 5152.797723] Hardware name: IBM,9080-HEX Power11 (architected) 0x820200 0xf000007 of:IBM,FW1110.01 (NH1110_069) hv:phyp pSeries
> >> [ 5152.797731] Workqueue: memcg drain_local_memcg_stock
> >> [ 5152.797741] NIP:  c00000000089f460 LR: c00000000089f45c CTR: 0000000000000000
> >> [ 5152.797749] REGS: c000000267417960 TRAP: 0700   Not tainted (6.19.0-next-20260216)
> >> [ 5152.797756] MSR:  800000000282b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE>  CR: 48000200  XER: 00000007
> >> [ 5152.797786] CFAR: c0000000001bc144 IRQMASK: 0
> >> [ 5152.797786] GPR00: c00000000089f45c c000000267417c00 c00000000243a500 c0000002699d1280
> >> [ 5152.797786] GPR04: 0000000000000004 0000000000000001 c0000000001bc0f4 0000000000000001
> >> [ 5152.797786] GPR08: a80e000000000000 0000000000000001 0000000000000003 a80e000000000000
> >> [ 5152.797786] GPR12: c00e0001a1a3cfb2 c000000d0ddea700 c0000001d9f80240
> >> c000000d0d1fefd0
> >> [ 5152.797786] GPR16: c000000007a5ab08 c0000001d9f80278 0000000000000000
> >> 0000000000000001
> >> [ 5152.797786] GPR20: c0000002699d1300 0000000000000000 0000000000000000
> >> c0000000032cef80
> >> [ 5152.797786] GPR24: 0000000000000002 c0000002699d1280 c000000d0d1fef83
> >> c000000d0d1fef98
> >> [ 5152.797786] GPR28: c000000d0d1fef80 ffffffffffffffff 000000000000003a
> >> c00000007d696000
> >> [ 5152.797885] NIP [c00000000089f460] page_counter_cancel+0x110/0x134
> >> [ 5152.797894] LR [c00000000089f45c] page_counter_cancel+0x10c/0x134
> >> [ 5152.797902] Call Trace:
> >> [ 5152.797907] [c000000267417c00] [c00000000089f45c] page_counter_cancel+0x10c/0x134 (unreliable)
> >> [ 5152.797920] [c000000267417c80] [c00000000089f8cc] page_counter_uncharge+0x3c/0x6c
> >> [ 5152.797930] [c000000267417cb0] [c0000000008ab630] drain_local_memcg_stock+0x198/0x464
> >> [ 5152.797942] [c000000267417da0] [c000000000204ffc] process_one_work+0x3d4/0x968
> >> [ 5152.797954] [c000000267417eb0] [c00000000020664c] worker_thread+0x308/0x614
> >> [ 5152.797964] [c000000267417f80] [c0000000002183f8] kthread+0x244/0x28c
> >> [ 5152.797974] [c000000267417fe0] [c00000000000ded8] start_kernel_thread+0x14/0x18
> >> [ 5152.797985] Code: 3d220289 892982ea 2c090000 40820028 3c62ff7a 39200001
> >> 3d420289 7fc5f378 38631be0 992a82ea 4b91cbed 60000000 <0fe00000> 38800008
> >> 7fe3fb78 4bfc35e1
> >> [ 5152.798021] ---[ end trace 0000000000000000 ]---
> > 
> > This does not seem related to xfs at all, I'm not Cc'ing linux-mm
> > because Vlastimil is already Cc'ed so, he knows better than me if this
> > is worth sharing with linux-mm.
> 
> This one also also seems memcg related, but no slab in the picture here.
> 

I found the following two config options interesting. Not sure if it is related
to this warning (and the other crash).

>> CONFIG_MEMCG_NMI_SAFETY_REQUIRES_ATOMIC=y
>> CONFIG_MEMCG_V1=y