Subject: Re: [PATCH v4 02/48] perf stat: Add aggr creators that are passed a cpu.

From: Arnaldo Carvalho de Melo <[email-masked]>
Date: Tue, 11 Jan 2022 16:49:54 -0300

Em Tue, Jan 11, 2022 at 04:33:01PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Tue, Jan 04, 2022 at 10:13:05PM -0800, Ian Rogers escreveu:
> > The cpu_map and index can get confused. Add variants of the cpu_map__get
> > routines that are passed a cpu. Make the existing cpu_map__get routines
> > use the new functions with a view to remove them when no longer used.
> > 
> > Reviewed-by: James Clark <[email-masked]>
> > Signed-off-by: Ian Rogers <[email-masked]>
> > ---
> >  tools/perf/util/cpumap.c | 79 +++++++++++++++++++++++-----------------
> >  tools/perf/util/cpumap.h |  6 ++-
> >  2 files changed, 51 insertions(+), 34 deletions(-)
> > 
> > diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
> > index 87d3eca9b872..49fba2c53822 100644
> > --- a/tools/perf/util/cpumap.c
> > +++ b/tools/perf/util/cpumap.c
> > @@ -128,21 +128,23 @@ int cpu_map__get_socket_id(int cpu)
> >  	return ret ?: value;
> >  }
> >  
> > -struct aggr_cpu_id cpu_map__get_socket(struct perf_cpu_map *map, int idx,
> > -					void *data __maybe_unused)
> > +struct aggr_cpu_id cpu_map__get_socket_aggr_by_cpu(int cpu, void *data __maybe_unused)
> >  {
> > -	int cpu;
> >  	struct aggr_cpu_id id = cpu_map__empty_aggr_cpu_id();
> >  
> > -	if (idx > map->nr)
> > -		return id;
> > -
> > -	cpu = map->map[idx];
> > -
> >  	id.socket = cpu_map__get_socket_id(cpu);
> >  	return id;
> >  }
> >  
> > +struct aggr_cpu_id cpu_map__get_socket(struct perf_cpu_map *map, int idx,
> > +				       void *data)
> > +{
> > +	if (idx < 0 || idx > map->nr)
> > +		return cpu_map__empty_aggr_cpu_id();
> > +
> > +	return cpu_map__get_socket_aggr_by_cpu(map->map[idx], data);
> > +}
> > +
> 
> 
> This 'idx < 0' wasn't in the original code nor is described in the
> comment log message, please avoid doing this, this may be harmless or
> even a good hardening, but either way would be interesting to have it in
> a separate patch. This eases review as in the end this code is just a
> refactoring, moving things around but in the end should be equivalent code.
> 
> There are a few more, please consider this and if you agree, to speed
> things up I can make the changes here, if I think this won't fallout in
> changes to subsequent patches touching this area.

Nah, should be harmless, and its too much work already, so lets leave it
as-is, but please consider this in the future.

- Arnaldo
 
> - Arnaldo
> 
> >  static int cmp_aggr_cpu_id(const void *a_pointer, const void *b_pointer)
> >  {
> >  	struct aggr_cpu_id *a = (struct aggr_cpu_id *)a_pointer;
> > @@ -200,15 +202,10 @@ int cpu_map__get_die_id(int cpu)
> >  	return ret ?: value;
> >  }
> >  
> > -struct aggr_cpu_id cpu_map__get_die(struct perf_cpu_map *map, int idx, void *data)
> > +struct aggr_cpu_id cpu_map__get_die_aggr_by_cpu(int cpu, void *data)
> >  {
> > -	int cpu, die;
> > -	struct aggr_cpu_id id = cpu_map__empty_aggr_cpu_id();
> > -
> > -	if (idx > map->nr)
> > -		return id;
> > -
> > -	cpu = map->map[idx];
> > +	struct aggr_cpu_id id;
> > +	int die;
> >  
> >  	die = cpu_map__get_die_id(cpu);
> >  	/* There is no die_id on legacy system. */
> > @@ -220,7 +217,7 @@ struct aggr_cpu_id cpu_map__get_die(struct perf_cpu_map *map, int idx, void *dat
> >  	 * with the socket ID and then add die to
> >  	 * make a unique ID.
> >  	 */
> > -	id = cpu_map__get_socket(map, idx, data);
> > +	id = cpu_map__get_socket_aggr_by_cpu(cpu, data);
> >  	if (cpu_map__aggr_cpu_id_is_empty(id))
> >  		return id;
> >  
> > @@ -228,6 +225,15 @@ struct aggr_cpu_id cpu_map__get_die(struct perf_cpu_map *map, int idx, void *dat
> >  	return id;
> >  }
> >  
> > +struct aggr_cpu_id cpu_map__get_die(struct perf_cpu_map *map, int idx,
> > +				    void *data)
> > +{
> > +	if (idx < 0 || idx > map->nr)
> > +		return cpu_map__empty_aggr_cpu_id();
> 
> Ditto
> 
> > +
> > +	return cpu_map__get_die_aggr_by_cpu(map->map[idx], data);
> > +}
> > +
> >  int cpu_map__get_core_id(int cpu)
> >  {
> >  	int value, ret = cpu__get_topology_int(cpu, "core_id", &value);
> > @@ -239,20 +245,13 @@ int cpu_map__get_node_id(int cpu)
> >  	return cpu__get_node(cpu);
> >  }
> >  
> > -struct aggr_cpu_id cpu_map__get_core(struct perf_cpu_map *map, int idx, void *data)
> > +struct aggr_cpu_id cpu_map__get_core_aggr_by_cpu(int cpu, void *data)
> >  {
> > -	int cpu;
> > -	struct aggr_cpu_id id = cpu_map__empty_aggr_cpu_id();
> > -
> > -	if (idx > map->nr)
> > -		return id;
> > -
> > -	cpu = map->map[idx];
> > -
> > -	cpu = cpu_map__get_core_id(cpu);
> > +	struct aggr_cpu_id id;
> > +	int core = cpu_map__get_core_id(cpu);
> >  
> >  	/* cpu_map__get_die returns a struct with socket and die set*/
> > -	id = cpu_map__get_die(map, idx, data);
> > +	id = cpu_map__get_die_aggr_by_cpu(cpu, data);
> >  	if (cpu_map__aggr_cpu_id_is_empty(id))
> >  		return id;
> >  
> > @@ -260,19 +259,33 @@ struct aggr_cpu_id cpu_map__get_core(struct perf_cpu_map *map, int idx, void *da
> >  	 * core_id is relative to socket and die, we need a global id.
> >  	 * So we combine the result from cpu_map__get_die with the core id
> >  	 */
> > -	id.core = cpu;
> > +	id.core = core;
> >  	return id;
> > +
> >  }
> >  
> > -struct aggr_cpu_id cpu_map__get_node(struct perf_cpu_map *map, int idx, void *data __maybe_unused)
> > +struct aggr_cpu_id cpu_map__get_core(struct perf_cpu_map *map, int idx, void *data)
> > +{
> > +	if (idx < 0 || idx > map->nr)
> > +		return cpu_map__empty_aggr_cpu_id();
> 
> Ditto
> 
> > +
> > +	return cpu_map__get_core_aggr_by_cpu(map->map[idx], data);
> > +}
> > +
> > +struct aggr_cpu_id cpu_map__get_node_aggr_by_cpu(int cpu, void *data __maybe_unused)
> >  {
> >  	struct aggr_cpu_id id = cpu_map__empty_aggr_cpu_id();
> >  
> > +	id.node = cpu_map__get_node_id(cpu);
> > +	return id;
> > +}
> > +
> > +struct aggr_cpu_id cpu_map__get_node(struct perf_cpu_map *map, int idx, void *data)
> > +{
> >  	if (idx < 0 || idx >= map->nr)
> > -		return id;
> > +		return cpu_map__empty_aggr_cpu_id();
> >  
> > -	id.node = cpu_map__get_node_id(map->map[idx]);
> > -	return id;
> > +	return cpu_map__get_node_aggr_by_cpu(map->map[idx], data);
> >  }
> >  
> >  int cpu_map__build_socket_map(struct perf_cpu_map *cpus, struct cpu_aggr_map **sockp)
> > diff --git a/tools/perf/util/cpumap.h b/tools/perf/util/cpumap.h
> > index a27eeaf086e8..c62d67704425 100644
> > --- a/tools/perf/util/cpumap.h
> > +++ b/tools/perf/util/cpumap.h
> > @@ -31,13 +31,17 @@ size_t cpu_map__snprint(struct perf_cpu_map *map, char *buf, size_t size);
> >  size_t cpu_map__snprint_mask(struct perf_cpu_map *map, char *buf, size_t size);
> >  size_t cpu_map__fprintf(struct perf_cpu_map *map, FILE *fp);
> >  int cpu_map__get_socket_id(int cpu);
> > +struct aggr_cpu_id cpu_map__get_socket_aggr_by_cpu(int cpu, void *data);
> >  struct aggr_cpu_id cpu_map__get_socket(struct perf_cpu_map *map, int idx, void *data);
> >  int cpu_map__get_die_id(int cpu);
> > +struct aggr_cpu_id cpu_map__get_die_aggr_by_cpu(int cpu, void *data);
> >  struct aggr_cpu_id cpu_map__get_die(struct perf_cpu_map *map, int idx, void *data);
> >  int cpu_map__get_core_id(int cpu);
> > +struct aggr_cpu_id cpu_map__get_core_aggr_by_cpu(int cpu, void *data);
> >  struct aggr_cpu_id cpu_map__get_core(struct perf_cpu_map *map, int idx, void *data);
> >  int cpu_map__get_node_id(int cpu);
> > -struct aggr_cpu_id  cpu_map__get_node(struct perf_cpu_map *map, int idx, void *data);
> > +struct aggr_cpu_id cpu_map__get_node_aggr_by_cpu(int cpu, void *data);
> > +struct aggr_cpu_id cpu_map__get_node(struct perf_cpu_map *map, int idx, void *data);
> >  int cpu_map__build_socket_map(struct perf_cpu_map *cpus, struct cpu_aggr_map **sockp);
> >  int cpu_map__build_die_map(struct perf_cpu_map *cpus, struct cpu_aggr_map **diep);
> >  int cpu_map__build_core_map(struct perf_cpu_map *cpus, struct cpu_aggr_map **corep);
> > -- 
> > 2.34.1.448.ga2b2bfdf31-goog
> 
> -- 
> 
> - Arnaldo

-- 

- Arnaldo

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