Re: [PATCH v6 10/12] perf stat: Use affinity for reading

[Jiri Olsa]

On Mon, Nov 11, 2019 at 04:59:39PM -0800, Andi Kleen wrote:

SNIP

>  
>  	return 0;
> @@ -325,15 +318,35 @@ static int read_counter(struct evsel *counter, struct timespec *rs)
>  static void read_counters(struct timespec *rs)
>  {
>  	struct evsel *counter;
> -	int ret;
> +	struct affinity affinity;
> +	int i, ncpus, cpu;
> +
> +	if (affinity__setup(&affinity) < 0)
> +		return;
> +
> +	ncpus = evsel_list->core.all_cpus->nr;
> +	if (!(target__has_cpu(&target) && !target__has_per_thread(&target)))
> +		ncpus = 1;

hum, could we propagate the negation inside amke this more readable?

  if (!target__has_cpu(&target) || target__has_per_thread(&target))

jirka

> +	evlist__for_each_cpu (evsel_list, i, cpu) {
> +		if (i >= ncpus)
> +			break;
> +		affinity__set(&affinity, cpu);
> +
> +		evlist__for_each_entry(evsel_list, counter) {
> +			if (evsel__cpu_iter_skip(counter, cpu))
> +				continue;
> +			if (!counter->err)
> +				counter->err = read_counter(counter, rs, counter->cpu_iter - 1);
> +		}
> +	}
> +	affinity__cleanup(&affinity);

SNIP