Re: [RFCv2 2/4] perf: util: Add more cpu_map helpers

[Jiri Olsa <jolsa@redhat.com>]

On Fri, Jul 15, 2016 at 11:08:11AM +0100, Mark Rutland wrote:
> In some cases it's necessry to figure out the map-local index of a given
> Linux logical CPU ID. Add a new helper, cpu_map__idx, to acquire this.
> As the logic is largely the same as the existing cpu_map__has, this is
> rewritten in terms of the new helper.
> 
> At the same time, add the inverse operation, cpu_map__cpu, which yields
> the logical CPU id for a map-local index. While this can be performed
> manually, wrapping this in a helper can make code more legible.
> 
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
> Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: Kan Liang <kan.liang@intel.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: linux-kernel@vger.kernel.org

Acked-by: Jiri Olsa <jolsa@kernel.org>

thanks,
jirka

> ---
>  tools/perf/util/cpumap.c | 14 ++++++++++++--
>  tools/perf/util/cpumap.h |  2 ++
>  2 files changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
> index 02d8016..efc88fe 100644
> --- a/tools/perf/util/cpumap.c
> +++ b/tools/perf/util/cpumap.c
> @@ -590,12 +590,22 @@ int cpu__setup_cpunode_map(void)
>  
>  bool cpu_map__has(struct cpu_map *cpus, int cpu)
>  {
> +	return cpu_map__idx(cpus, cpu) != -1;
> +}
> +
> +int cpu_map__idx(struct cpu_map *cpus, int cpu)
> +{
>  	int i;
>  
>  	for (i = 0; i < cpus->nr; ++i) {
>  		if (cpus->map[i] == cpu)
> -			return true;
> +			return i;
>  	}
>  
> -	return false;
> +	return -1;
> +}
> +
> +int cpu_map__cpu(struct cpu_map *cpus, int idx)
> +{
> +	return cpus->map[idx];
>  }
> diff --git a/tools/perf/util/cpumap.h b/tools/perf/util/cpumap.h
> index 1a0a350..46f7642 100644
> --- a/tools/perf/util/cpumap.h
> +++ b/tools/perf/util/cpumap.h
> @@ -67,5 +67,7 @@ int cpu_map__build_map(struct cpu_map *cpus, struct cpu_map **res,
>  		       int (*f)(struct cpu_map *map, int cpu, void *data),
>  		       void *data);
>  
> +int cpu_map__cpu(struct cpu_map *cpus, int idx);
>  bool cpu_map__has(struct cpu_map *cpus, int cpu);
> +int cpu_map__idx(struct cpu_map *cpus, int cpu);
>  #endif /* __PERF_CPUMAP_H */
> -- 
> 1.9.1
>