Re: Dealing with the NMI mess

[Linus Torvalds]

On Fri, Jul 24, 2015 at 12:55 PM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> I worry that we'll end up running the do_debug() handlers from effective
> NMI context.
>
> The NMI might have preempted locks which these handlers require etc..

If #DB takes any locks like that, then #DB is broken.

Pretty much by definition, a data breakpoint can happen on pretty much
absolutely any code. This is in no way NMI-specific as far as I can
tell.

Do we really take locks in the #DB handler?

                     Linus
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