Re: upstream kernel crashes

[Andres Freund]

On 2022-08-15 13:53:31 -0700, Andres Freund wrote:
> The reason the debug patch didn't change anything, and that my debug printk
> didn't show, is that gcp uses the legacy paths...
> 
> If there were a bug in the legacy path, it'd explain why the problem only
> shows on gcp, and not in other situations.
> 
> I'll queue testing the legacy path with the equivalent change.

Booting with the equivalent change, atop 5.19, in the legacy setup_vq()
reliably causes boot to hang:

[    0.718768] ACPI: button: Sleep Button [SLPF]
[    0.721989] ACPI: \_SB_.LNKC: Enabled at IRQ 11
[    0.722688] adebug: use legacy: 0
[    0.722724] virtio-pci 0000:00:03.0: virtio_pci: leaving for legacy driver
[    0.724286] adebug: probe modern: -19
[    0.727353] ACPI: \_SB_.LNKD: Enabled at IRQ 10
[    0.728719] adebug: use legacy: 0
[    0.728766] virtio-pci 0000:00:04.0: virtio_pci: leaving for legacy driver
[    0.730422] adebug: probe modern: -19
[    0.733552] ACPI: \_SB_.LNKA: Enabled at IRQ 10
[    0.734923] adebug: use legacy: 0
[    0.734957] virtio-pci 0000:00:05.0: virtio_pci: leaving for legacy driver
[    0.736426] adebug: probe modern: -19
[    0.739039] ACPI: \_SB_.LNKB: Enabled at IRQ 11
[    0.740350] adebug: use legacy: 0
[    0.740390] virtio-pci 0000:00:06.0: virtio_pci: leaving for legacy driver
[    0.742142] adebug: probe modern: -19
[    0.747627] adebug: legacy setup_vq
[    0.748243] virtio-pci 0000:00:05.0: adebug: legacy: not limiting queue size, only 256
[    0.751081] adebug: legacy setup_vq
[    0.751110] virtio-pci 0000:00:05.0: adebug: legacy: not limiting queue size, only 256
[    0.754028] adebug: legacy setup_vq
[    0.754059] virtio-pci 0000:00:05.0: adebug: legacy: not limiting queue size, only 1
[    0.757760] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
[    0.759135] 00:03: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
[    0.760399] 00:04: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200) is a 16550A
[    0.761610] 00:05: ttyS2 at I/O 0x3e8 (irq = 6, base_baud = 115200) is a 16550A
[    0.762923] 00:06: ttyS3 at I/O 0x2e8 (irq = 7, base_baud = 115200) is a 16550A
[    0.764222] Non-volatile memory driver v1.3
[    0.768857] adebug: legacy setup_vq
[    0.768882] virtio-pci 0000:00:06.0: adebug: legacy: not limiting queue size, only 256
[    0.773002] Linux agpgart interface v0.103
[    0.775424] loop: module loaded
[    0.780513] adebug: legacy setup_vq
[    0.780538] virtio-pci 0000:00:03.0: adebug: legacy: limiting queue size from 8192 to 1024
[    0.784075] adebug: legacy setup_vq
[    0.784104] virtio-pci 0000:00:03.0: adebug: legacy: limiting queue size from 8192 to 1024
[    0.787073] adebug: legacy setup_vq
[    0.787101] virtio-pci 0000:00:03.0: adebug: legacy: limiting queue size from 8192 to 1024
[    0.790379] scsi host0: Virtio SCSI HBA
[    0.795968] Freeing initrd memory: 7236K

Greetings,

Andres Freund