Re: [PATCHv2 0/4] zsmalloc: make zspage chain size configurable

[Sergey Senozhatsky]

On (23/01/13 11:57), Mike Kravetz wrote:
> Hi Sergey,
> 
> The following BUG shows up after this series in linux-next.  I can easily
> recreate by doing the following:
> 
> # echo large_value > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
> where 'large_value' is a so big that there could never possibly be that
> many 2MB huge pages in the system.

I get migration warnins with the zsmalloc series reverted.
I guess the problem is somewhere else. Can you double check
on you side?


[   87.208255] ------------[ cut here ]------------
[   87.209431] WARNING: CPU: 18 PID: 300 at mm/migrate.c:995 move_to_new_folio+0x1ef/0x260
[   87.211993] Modules linked in: deflate zlib_deflate zstd zstd_compress zram
[   87.214287] CPU: 18 PID: 300 Comm: kcompactd0 Tainted: G                 N 6.2.0-rc3-next-20230113+ #385
[   87.217529] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-4 04/01/2014
[   87.220131] RIP: 0010:move_to_new_folio+0x1ef/0x260
[   87.221892] Code: 84 c0 74 78 48 8b 43 18 44 89 ea 48 89 de 4c 89 e7 ff 50 06 85 c0 0f 85 a9 fe ff ff 48 8b 03 a9 00 00 04 00 0f 85 7a fe ff ff <0f> 0b e9 73 fe ff ff 48 8b 03 f6 c4 20 74 2a be c0 0c 00 00 48 89
[   87.226514] RSP: 0018:ffffc90000b9fb08 EFLAGS: 00010246
[   87.227879] RAX: 4000000000000021 RBX: ffffea0000890500 RCX: 0000000000000000
[   87.230948] RDX: 0000000000000000 RSI: ffffffff81e6f950 RDI: ffffea0000890500
[   87.233026] RBP: ffffea0000890500 R08: 0000001e82ec3c3e R09: 0000000000000001
[   87.235517] R10: 00000000ffffffff R11: 00000000ffffffff R12: ffffea00015a26c0
[   87.237807] R13: 0000000000000001 R14: ffffea00015a2680 R15: ffffea00008904c0
[   87.239438] FS:  0000000000000000(0000) GS:ffff888624200000(0000) knlGS:0000000000000000
[   87.241303] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   87.242627] CR2: 00007fe537ebbdb8 CR3: 0000000110a0a004 CR4: 0000000000770ee0
[   87.244283] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   87.245913] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   87.247559] PKRU: 55555554
[   87.248269] Call Trace:
[   87.248862]  <TASK>
[   87.249370]  ? lock_is_held_type+0xd9/0x130
[   87.250377]  migrate_pages_batch+0x553/0xc80
[   87.251513]  ? move_freelist_tail+0xc0/0xc0
[   87.252545]  ? isolate_freepages+0x290/0x290
[   87.253654]  ? trace_mm_migrate_pages+0xf0/0xf0
[   87.254901]  migrate_pages+0x1ae/0x330
[   87.255877]  ? isolate_freepages+0x290/0x290
[   87.257015]  ? move_freelist_tail+0xc0/0xc0
[   87.258213]  compact_zone+0x528/0x6a0
[   87.260911]  proactive_compact_node+0x87/0xd0
[   87.262090]  kcompactd+0x1ca/0x360
[   87.263018]  ? swake_up_all+0xe0/0xe0
[   87.264101]  ? kcompactd_do_work+0x240/0x240
[   87.265243]  kthread+0xec/0x110
[   87.266031]  ? kthread_complete_and_exit+0x20/0x20
[   87.267268]  ret_from_fork+0x1f/0x30
[   87.268243]  </TASK>
[   87.268984] irq event stamp: 311113
[   87.269930] hardirqs last  enabled at (311125): [<ffffffff810da6c2>] __up_console_sem+0x52/0x60
[   87.272235] hardirqs last disabled at (311134): [<ffffffff810da6a7>] __up_console_sem+0x37/0x60
[   87.275707] softirqs last  enabled at (311088): [<ffffffff819d2b2c>] __do_softirq+0x21c/0x31f
[   87.278450] softirqs last disabled at (311083): [<ffffffff81070b8d>] __irq_exit_rcu+0xad/0x120
[   87.280555] ---[ end trace 0000000000000000 ]---