Re: [PATCH -v3] perf, x86: try to handle unknown nmis with running perfctrs

[Robert Richter <robert.richter@amd.com>]

On 19.08.10 06:45:53, Peter Zijlstra wrote:
> I queued it with that part changed to:
> 
> +       this_nmi = percpu_read(irq_stat.__nmi_count);
> +       if ((handled > 1) ||
> +               /* the next nmi could be a back-to-back nmi */
> +           ((__get_cpu_var(nmi).marked == this_nmi) &&
> +            (__get_cpu_var(nmi).handled > 1))) {
> +               /*
> +                * We could have two subsequent back-to-back nmis: The
> +                * first handles more than one counter, the 2nd
> +                * handles only one counter and the 3rd handles no
> +                * counter.
> +                *
> +                * This is the 2nd nmi because the previous was
> +                * handling more than one counter. We will mark the
> +                * next (3rd) and then drop it if unhandled.
> +                */
> +               __get_cpu_var(nmi).marked       = this_nmi + 1;
> +               __get_cpu_var(nmi).handled      = handled;
> +       }
> 
>         return NOTIFY_STOP;
>  }

I am fine with this. Thanks Peter.

-Robert

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