Re: [PATCH 2/2] x86/crash: Disable the watchdog NMIs on the crashing cpu.

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 15/11/13 21:01, David Vrabel wrote:
> On 15/11/13 20:32, Andrew Cooper wrote:
>> PVOps Linux as a kexec image shoots itself in the foot otherwise.
>>
>> On a Core2 system, Linux declares a firmware bug and tries to invert some bits
>> in the performance counter register.  It ends up setting the number of retired
>> instructions to generate another NMI to fewer instructions than the NMI
>> interrupt path itself, and ceases to make any useful progress.
>>
>> While this is not strictly Xen's fault, Xen can at least be kind and leave the
>> kexec environment with fewer issues to deal with.
> I don't appreciate my commit message being rewritten in this way.
>
> My original commit message was:
>
>   "kexec: disable the NMI watchdog during a crash
>
>   nmi_shootdown_cpus() is called during a crash to park all the other
>   CPUs.  This changes the NMI trap handlers which means there's no point
>   in having the watchdog still running.
>
>   This also disables the watchdog before executing any crash kexec image
>   and prevents the image from receiving unexpected NMIs."
>
> David

Sorry - I took the patch as-was out of the patch queue, which had no
message.  I forgot to check the commit history for the message being
there, and therefore wrote the message myself from scratch.

I am not too fussed which message gets used.

~Andrew