Re: [PATCH V4 04/23] perf/x86/intel: Support adaptive PEBSv4

Andi Kleen
2019-03-26T22:24:44Z

> + for (at = base; at < top; at += cpuc->pebs_record_size) {
> + u64 pebs_status;
> +
> + pebs_status = get_pebs_status(at) & cpuc->pebs_enabled;
> + pebs_status &= mask;
> +
> + for_each_set_bit(bit, (unsigned long *)&pebs_status, size)
> + counts[bit]++;
> + }

On Icelake pebs_status is always reliable, so I don't think we need
the two pass walking.

-Andi

> +
> + for (bit = 0; bit < size; bit++) {
> + if (counts[bit] == 0)
> + continue;
> +
> + event = cpuc->events[bit];
> + if (WARN_ON_ONCE(!event))
> + continue;
> +
> + if (WARN_ON_ONCE(!event->attr.precise_ip))
> + continue;
> +
> + __intel_pmu_pebs_event(event, iregs, base,
> + top, bit, counts[bit],
> + setup_pebs_adaptive_sample_data);
> + }
> +}