Re: [RFC][PATCH 0/3] x86/nmi: Print all cpu stacks from NMI safely

Jiri Kosina
2014-06-19T23:39:04Z

On Thu, 19 Jun 2014, Steven Rostedt wrote:

> > I don't think there is a need for a global stop_machine()-like
> > synchronization here. The printing CPU will be sending IPI to the CPU N+1
> > only after it has finished printing CPU N stacktrace.
>
> So you plan on sending an IPI to a CPU then wait for it to acknowledge
> that it is spinning, and then print out the data and then tell the CPU
> it can stop spinning?

Yes, that was exactly my idea. You have to be synchronized with the CPU
receiving the NMI anyway in case you'd like to get its pt_regs and dump
those as part of the dump.

--
Jiri Kosina
SUSE Labs