We've been running self-built 5.10.x kernels on DL380 hosts for quite a while, also inside the VMs there. With I think 5.10.90 three weeks or so back, we experienced a lockup upon umounting a larger, dirty filesystem on the host side, unfortunately without capturing a backtrace back then. Today something feeling similar, happened again, on a machine running 5.10.93 both on the host and inside its 10 various VMs. Problem showed shortly (minutes) after shutting down one of the VMs (few hundred GB memory / dataset, VM shutdown was complete already; direct I/O), and then some LVM volume renames, a quick short outside ext4 mount followed by an umount (8 GB volume, probably a few hundred megabyte only to write). Actually monitoring suggests that disk writes were already done about a minute before the onset. What we then experienced, was the following BUG:, followed by one after the other CPU saying goodbye with soft lockup messages over the course of a few minutes; meanwhile there was no more pinging the box, logging in on console, etc. We hard powercycled and it recovered fully. here's the BUG that was logged; if it is useful for someone to see the followup soft lockup messages, tell me + I'll add them. Feb 02 15:22:27 kvm3j kernel: BUG: unable to handle page fault for address: ffffebde00000008 Feb 02 15:22:27 kvm3j kernel: #PF: supervisor read access in kernel mode Feb 02 15:22:27 kvm3j kernel: #PF: error_code(0x0000) - not-present page Feb 02 15:22:27 kvm3j kernel: Oops: 0000 [#1] SMP PTI Feb 02 15:22:27 kvm3j kernel: CPU: 7 PID: 39833 Comm: kworker/7:0 Tainted: G I 5.10.93-kvm #1 Feb 02 15:22:27 kvm3j kernel: Hardware name: HP ProLiant DL380p Gen8, BIOS P70 12/20/2013 Feb 02 15:22:27 kvm3j kernel: Workqueue: events cache_reap Feb 02 15:22:27 kvm3j kernel: RIP: 0010:free_block.constprop.0+0xc0/0x1f0 Feb 02 15:22:27 kvm3j kernel: Code: 4c 8b 16 4c 89 d0 48 01 e8 0f 82 32 01 00 00 4c 89 f2 48 bb 00 00 00 00 00 ea ff ff 48 01 d0 48 c1 e8 0c 48 c1 e0 06 48 01 d8 <48> 8b 50 08 48 8d 4a ff 83 e2 01 48 > Feb 02 15:22:27 kvm3j kernel: RSP: 0018:ffffc9000252bdc8 EFLAGS: 00010086 Feb 02 15:22:27 kvm3j kernel: RAX: ffffebde00000000 RBX: ffffea0000000000 RCX: ffff888889141b00 Feb 02 15:22:27 kvm3j kernel: RDX: 0000777f80000000 RSI: ffff893d3edf3400 RDI: ffff8881000403c0 Feb 02 15:22:27 kvm3j kernel: RBP: 0000000080000000 R08: ffff888100041300 R09: 0000000000000003 Feb 02 15:22:27 kvm3j kernel: R10: 0000000000000000 R11: ffff888100041308 R12: dead000000000122 Feb 02 15:22:27 kvm3j kernel: R13: dead000000000100 R14: 0000777f80000000 R15: ffff893ed8780d60 Feb 02 15:22:27 kvm3j kernel: FS: 0000000000000000(0000) GS:ffff893d3edc0000(0000) knlGS:0000000000000000 Feb 02 15:22:27 kvm3j kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Feb 02 15:22:27 kvm3j kernel: CR2: ffffebde00000008 CR3: 000000048c4aa002 CR4: 00000000001726e0 Feb 02 15:22:27 kvm3j kernel: Call Trace: Feb 02 15:22:27 kvm3j kernel: drain_array_locked.constprop.0+0x2e/0x80 Feb 02 15:22:27 kvm3j kernel: drain_array.constprop.0+0x54/0x70 Feb 02 15:22:27 kvm3j kernel: cache_reap+0x6c/0x100 Feb 02 15:22:27 kvm3j kernel: process_one_work+0x1cf/0x360 Feb 02 15:22:27 kvm3j kernel: worker_thread+0x45/0x3a0 Feb 02 15:22:27 kvm3j kernel: ? process_one_work+0x360/0x360 Feb 02 15:22:27 kvm3j kernel: kthread+0x116/0x130 Feb 02 15:22:27 kvm3j kernel: ? kthread_create_worker_on_cpu+0x40/0x40 Feb 02 15:22:27 kvm3j kernel: ret_from_fork+0x22/0x30 Feb 02 15:22:27 kvm3j kernel: Modules linked in: hpilo Feb 02 15:22:27 kvm3j kernel: CR2: ffffebde00000008 Feb 02 15:22:27 kvm3j kernel: ---[ end trace ded3153d86a92898 ]--- Feb 02 15:22:27 kvm3j kernel: RIP: 0010:free_block.constprop.0+0xc0/0x1f0 Feb 02 15:22:27 kvm3j kernel: Code: 4c 8b 16 4c 89 d0 48 01 e8 0f 82 32 01 00 00 4c 89 f2 48 bb 00 00 00 00 00 ea ff ff 48 01 d0 48 c1 e8 0c 48 c1 e0 06 48 01 d8 <48> 8b 50 08 48 8d 4a ff 83 e2 01 48 > Feb 02 15:22:27 kvm3j kernel: RSP: 0018:ffffc9000252bdc8 EFLAGS: 00010086 Feb 02 15:22:27 kvm3j kernel: RAX: ffffebde00000000 RBX: ffffea0000000000 RCX: ffff888889141b00 Feb 02 15:22:27 kvm3j kernel: RDX: 0000777f80000000 RSI: ffff893d3edf3400 RDI: ffff8881000403c0 Feb 02 15:22:27 kvm3j kernel: RBP: 0000000080000000 R08: ffff888100041300 R09: 0000000000000003 Feb 02 15:22:27 kvm3j kernel: R10: 0000000000000000 R11: ffff888100041308 R12: dead000000000122 Feb 02 15:22:27 kvm3j kernel: R13: dead000000000100 R14: 0000777f80000000 R15: ffff893ed8780d60 Feb 02 15:22:27 kvm3j kernel: FS: 0000000000000000(0000) GS:ffff893d3edc0000(0000) knlGS:0000000000000000 Feb 02 15:22:27 kvm3j kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Feb 02 15:22:27 kvm3j kernel: CR2: ffffebde00000008 CR3: 000000048c4aa002 CR4: 00000000001726e0
Upon checking the previous event we experienced, I actually found precisely the same place faulting, with a 5.10.90 kernel. We've been running earlier 5.10.X kernels, .80 before that, for a long while, so that is probably something new. The event on January 13th was a DL385 Gen10plus with AMD processor, 64 cores, the one today was a DL380 Gen8 with Intel processor, 12 cores. Pretty much ruling out hardware. I will attach both of the captured kernel message logs
And it happened a third time. Again a 5.10.93 kernel and similar work we did. To complete the "what we did" picture * WHILE a set of VMs, including one taking hundreds of GB of memory, ran (fine) * we create a fresh ext4 filesystem on the host, mount it, fill it with rsync to the tune of another few hundred GB * I/O from that settled (nr_dirty on the host down to nothing) * larger VM this time round, shut down intentionally, actually stopped, qemu terminated for a few minutes * umounting the large new ext4 outside * which also completes (from userlevel / shell view) but is then soon followed by the BUG + hang
I meanwhile switched to 5.15, and also from SLAB to SLUB, and didn't experience these symptoms anymore.
Sorry, I for some time lost track of this. (In reply to Patrick Schaaf from comment #3) > I meanwhile switched to 5.15, and also from SLAB to SLUB, and didn't > experience these symptoms anymore. I just wanted to get this rolling again, but I guess in that case it might be not worth it, as without a bisection I guess it will be hard to find anyone looking into this. Is that okay for you?
Fine with me Thorsten and thanks for the attempt at pushing this on. I'm totally happy with having switched to 5.15, my workloads love it.