Re: [PATCH] x86: sysctl to allow panic on IOCK NMI error

Maciej W. Rozycki
2009-06-30T22:22:53Z

On Wed, 24 Jun 2009, Greg KH wrote:

> This patch introduces a sysctl /proc/sys/kernel/panic_on_io_nmi, which
> defaults to 0 (off).
>
> When enabled, the kernel panics when the kernel receives an NMI caused
> by an IO error.
>
> The IO error triggered NMI indicates a serious system condition, which
> could result in IO data corruption. Rather than contiuing, panicing and
> dumping might be a better choice, so one can figure out what's causing
> the IO error.
>
> This could be especially important to companies running IO intensive
> applications where corruption must be avoided, e.g. a banks databases.

These days an IOCK NMI typically happens in response to a PCI SERR -- it
may be useful to traverse PCI buses to find the offender and dump this
information on this occasion too. The south bridge may have additional
status too.

Maciej