Kernel stack trace seen with edge kernel on opi5+

Hi all,

I'm using a UEFI based edge ubuntu 24.04 image which reported a kernel stack trace (system still seems functional and no ongoing issue/messages) -
 

[   22.382942] rcu: INFO: rcu_sched detected expedited stalls on CPUs/tasks: { 5-.... } 6 jiffies s: 381 root: 0x20/.
[   22.382966] rcu: blocking rcu_node structures (internal RCU debug):
[   22.382972] Sending NMI from CPU 7 to CPUs 5:
[   22.382983] NMI backtrace for cpu 5
[   22.382995] CPU: 5 PID: 92 Comm: kworker/u16:2 Tainted: G        W          6.8.5-edge-arm64 #2
[   22.383004] Hardware name: Orange Pi Orange Pi 5 Plus/Orange Pi 5 Plus, BIOS v0.9.1 10/12/2023
[   22.383009] Workqueue: writeback wb_workfn (flush-252:1)
[   22.383024] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   22.383032] pc : FSE_buildCTable_wksp+0x1ac/0x340
[   22.383041] lr : 0xffff80008847c0ee
[   22.383047] sp : ffff80008309b0e0
[   22.383051] x29: ffff80008309b0e0 x28: ffff00010117424b x27: 0000000000000006
[   22.383061] x26: ffff80008309b2f8 x25: 0000000000000007 x24: ffff00010117424b
[   22.383069] x23: 0000000000001db5 x22: ffff8000885b4ad8 x21: ffff800088479ed4
[   22.383077] x20: 000000000000002c x19: 0101010101010101 x18: 0000000000000080
[   22.383086] x17: 0000000000000080 x16: ffff80008847c0ee x15: 0000000000000080
[   22.383094] x14: 0000000000000104 x13: ffff800088479ed4 x12: ffff80008847c094
[   22.383103] x11: 000000000000002c x10: 0000000000000007 x9 : ffff80008847c100
[   22.383111] x8 : 000000000000002c x7 : 000000000000002c x6 : ffff80008847c15c
[   22.383119] x5 : 0000000000000004 x4 : 0000000000000023 x3 : 00000000000000ee
[   22.383127] x2 : 0000000000000006 x1 : 0000000000000048 x0 : 000000000000006f
[   22.383135] Call trace:
[   22.383139]  FSE_buildCTable_wksp+0x1ac/0x340
[   22.383145]  ZSTD_buildCTable+0x1d0/0x1e8
[   22.383155]  ZSTD_buildSequencesStatistics+0x31c/0x3b8
[   22.383164]  ZSTD_entropyCompressSeqStore_internal.constprop.0+0x170/0x2c0
[   22.383172]  ZSTD_compressBlock_internal+0x8c/0x200
[   22.383180]  ZSTD_compressContinue_internal+0x1e0/0xa88
[   22.383187]  ZSTD_compressEnd+0x34/0x1a0
[   22.383195]  ZSTD_compressStream2+0x514/0x600
[   22.383203]  ZSTD_compress2+0x68/0xb8
[   22.383211]  zstd_compress_cctx+0xa0/0xc0
[   22.383216]  __zstd_compress+0x70/0xc8 [zstd]
[   22.383232]  zstd_compress+0x30/0x48 [zstd]
[   22.383245]  crypto_comp_compress+0x20/0x38
[   22.383251]  zcomp_compress+0x2c/0x40 [zram]
[   22.383267]  zram_submit_bio+0x3dc/0x9a0 [zram]
[   22.383280]  __submit_bio+0xb4/0x148
[   22.383290]  submit_bio_noacct_nocheck+0x10c/0x2e8
[   22.383299]  submit_bio_noacct+0x184/0x530
[   22.383308]  submit_bio+0xa4/0x118
[   22.383317]  ext4_io_submit+0x38/0x68
[   22.383324]  ext4_do_writepages+0x568/0xb48
[   22.383332]  ext4_writepages+0xa4/0x138
[   22.383340]  do_writepages+0x90/0x210
[   22.383346]  __writeback_single_inode+0x48/0x400
[   22.383352]  writeback_sb_inodes+0x234/0x5e8
[   22.383356]  __writeback_inodes_wb+0x68/0x150
[   22.383361]  wb_writeback+0x294/0x3a0
[   22.383366]  wb_workfn+0x32c/0x5d0
[   22.383371]  process_one_work+0x164/0x360
[   22.383378]  worker_thread+0x2b8/0x510
[   22.383384]  kthread+0xec/0xf8
[   22.383389]  ret_from_fork+0x10/0x20

Details from armbianmonitor -u at https://paste.armbian.com/tuxuroyunu

cheers

Andrew