On 6/30/22 00:04, Pingfan Liu wrote:
> Currently, kdump may experience failure on some aws aarch64 platform.
> The final scenario is:
>
> [ 79.145089] printk: console [ttyS0] disabled
> Then the system has no response any more. And after reboot, there is no
> vmcore generated under /var/crash/. More detail [1].
>
> In a short word, it is caused by the irqpoll policy and some unknown
> acpi issue. The serial device is hot-removed as a pci device.
>
> More detailed, the irqpoll policy demands to iterate over all interrupt
> handler, if the interrupt line is shared, then the handler is
> dispatched. And acpi handler acpi_irq() is on a shared interrupt line,
> so it is called. But for some unknown reason, the acpi hardware regs
> hold wrong state, and the acpi driver decides that a hot-removed event
> happens on a pci slot, which finally removes the pci serial device.
>
> To tackle this issue by removing the irqpoll parameter on aws aarch64
> platform, until the real root cause in acpi is found and resolved.
>
> [1]:
https://bugzilla.redhat.com/show_bug.cgi?id=2080468#c0
>
> Signed-off-by: Pingfan Liu <piliu(a)redhat.com>
> ---
> kdumpctl | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/kdumpctl b/kdumpctl
> index 6188d47..3eb57e3 100755
> --- a/kdumpctl
> +++ b/kdumpctl
> @@ -641,6 +641,18 @@ function remove_kdump_kernel_key()
> keyctl unlink "$KDUMP_KEY_ID" %:.ima
> }
>
> +function is_aws_aarch64()
> +{
> + local _bios_model;
> +
> + _bios_model=$(lscpu | grep "BIOS Model name")
I'm not sure lscpu is reliable here. I just checked two instance
types (two I had running were a1.metal and c6g.xlarge) and this didn't work.
Actually, it was because I was running `lscpu` as non-root. As root it shows up:
```
[bound] -bash-5.1$ sudo lscpu | grep "BIOS Model name"
BIOS Model name: AWS Graviton2 AWS Graviton2 CPU @ 2.5GHz
```
So this LGTM.