Re: [PATCH v7 2/4] nmi_backtrace: do a local dump_stack() instead of a self-NMI

[Petr Mladek]

On Mon 2016-08-08 12:03:36, Chris Metcalf wrote:
> Currently on arm there is code that checks whether it should call
> dump_stack() explicitly, to avoid trying to raise an NMI when the
> current context is not preemptible by the backtrace IPI.  Similarly,
> the forthcoming arch/tile support uses an IPI mechanism that does
> not support generating an NMI to self.
> 
> Accordingly, move the code that guards this case into the generic
> mechanism, and invoke it unconditionally whenever we want a
> backtrace of the current cpu.  It seems plausible that in all cases,
> dump_stack() will generate better information than generating a
> stack from the NMI handler.  The register state will be missing,
> but that state is likely not particularly helpful in any case.
> 
> Or, if we think it is helpful, we should be capturing and emitting
> the current register state in all cases when regs == NULL is passed
> to nmi_cpu_backtrace().
> 
> Signed-off-by: Chris Metcalf <cmetcalf@xxxxxxxxxxxx>
> Acked-by: Aaron Tomlin <atomlin@xxxxxxxxxx>

Sounds and looks fine to me.

Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>

Best Regards,
Petr Mladek