Re: [PATCH] perf: fix topology test on systems with sparse CPUs

[Jiri Olsa]

On Mon, Jan 30, 2017 at 05:53:34PM +0100, Jan Stancek wrote:

SNIP

> diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
> index bb964e86b09d..0c2cae807a61 100644
> --- a/tools/perf/util/env.c
> +++ b/tools/perf/util/env.c
> @@ -60,29 +60,45 @@ int perf_env__set_cmdline(struct perf_env *env, int argc, const char *argv[])
>  
>  int perf_env__read_cpu_topology_map(struct perf_env *env)
>  {
> -	int cpu, nr_cpus;
> +	int cpu, nr_cpus, i, err = 0;
> +	struct cpu_map *map;
>  
>  	if (env->cpu != NULL)
>  		return 0;
>  
> -	if (env->nr_cpus_avail == 0)
> -		env->nr_cpus_avail = sysconf(_SC_NPROCESSORS_CONF);
> +	map = cpu_map__new(NULL);

could you please put comment in here, explaining that
cpu_map__new(NULL) makes map with current online cpus

thanks,
jirka