Mathieu Poirier <mathieu.poir...@linaro.org> writes:

> +static void etm_event_start(struct perf_event *event, int flags)
> +{
> +     int cpu = smp_processor_id();
> +     struct etm_cpu_data *cpu_data;
> +     struct etm_event_data *event_data;
> +     struct perf_output_handle *handle = this_cpu_ptr(&ctx_handle);
> +     struct coresight_device *sink, *csdev = per_cpu(csdev_src, cpu);
> +
> +     if (!csdev)
> +             goto fail;
> +
> +     /*
> +      * Deal with the ring buffer API and get a handle on the
> +      * session's information.
> +      */
> +     event_data = perf_aux_output_begin(handle, event);
> +     if (WARN_ON_ONCE(!event_data))
> +             goto fail;

Hmm, perf_aux_output_begin() returning NULL is not WARN-worthy and is
actually a normal situation, for example, if the buffer is not
configured yet (which like I suggested in the other email should be a
separate thing from the *event* configuration).

perf_aux_output_begin() will also return NULL if there's no room in the
buffer.

Regards,
--
Alex
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to