> On Fri, Sep 25, 2015 at 08:28:11PM +0900, 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. > > So that they can get really stuck when the crash kernel crashes, right? > ;-) No, it is different from my intention. `mistakenly' in the above means; they issue NMI due to a misconception that the monitored host is stuck in the 1st kernel while it is actually taking a crash dump in the 2nd kernel. To avoid this kind of accident, there is a tool such as fence_kdump which notifies "I'm taking a crash dump, so don't send NMI" to the HA clustering software. However, there is a time window between kernel panic and the notification. "noextnmi" allows users to avoid this kind of accident all the time of 2nd kernel. Regards, Hidehiro Kawai Hitachi, Ltd. Research & Development Group
