[V4 PATCH 4/4] x86/apic: Introduce noextnmi boot option
tglx at linutronix.de
Tue Oct 13 13:22:58 PDT 2015
On Fri, 25 Sep 2015, Hidehiro Kawai wrote:
> This patch introduces new boot option "noextnmi" which disables
> external NMI. This option is useful for the dump capture kernel
> so that an HA application or administrator wouldn't mistakenly
> shoot down the kernel by NMI.
> Currently, only x86 supports this option.
You might add that is can be used for debugging purposes as
well. External NMIs can be their own source of trouble. :)
> Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez at hitachi.com>
> Cc: Thomas Gleixner <tglx at linutronix.de>
> Cc: Ingo Molnar <mingo at redhat.com>
> Cc: "H. Peter Anvin" <hpa at zytor.com>
> Cc: Jonathan Corbet <corbet at lwn.net>
> Documentation/kernel-parameters.txt | 4 ++++
> arch/x86/kernel/apic/apic.c | 17 ++++++++++++++++-
> 2 files changed, 20 insertions(+), 1 deletion(-)
> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> index 22a4b68..8bcaccd 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -2379,6 +2379,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
> noexec=on: enable non-executable mappings (default)
> noexec=off: disable non-executable mappings
> + noextnmi [X86]
> + Mask external NMI. This option is useful for a
> + dump capture kernel to be shot down by NMI.
That should read: "...not to be shot down", right?
Other than that.
Acked-by: Thomas Gleixner <tglx at linutronix.de>
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