Re: [PATCH RFC 02/10] perf,tools: Support new sort type --socket

[Jiri Olsa <jolsa@redhat.com>]

On Fri, Aug 21, 2015 at 08:25:24PM +0000, Liang, Kan wrote:

SNIP

> > 
> > we need global topology information in perf.data and use the mapping
> > from there, we can't use current server info
> > 
> > we currently store core_siblings_list and thread_siblings_list, in topology
> > FEATURE, which is probably not enough
> >
> 
> core_siblings_list  includes the cpu list in the same socket.
> thread_siblings_list includes the cpu list in the same core.
> numa_nodes includes the cpu list for each node.
> 
> It looks we have enough data from topology FEATURE.

hum, haven't hecked deeply.. how will you get core id for cpu?

> 
> What do you think about the function as below?
> It gets the socket id from env.

some sort of caching would be nice, I guess we could
store those cpumap objects within perf_session_env

jirka

> 
> +int
> +perf_env_get_socket(struct perf_session_env *env, int cpu)
> +{
> +	int socket_nr, cpu_nr, i, j;
> +	struct cpu_map *socket_map = NULL;
> +	char *str;
> +
> +	if (env == NULL)
> +		return -1;
> +
> +	socket_nr = env->nr_sibling_cores;
> +	str = env->sibling_cores;
> +
> +	for (i = 0; i < socket_nr; i++) {
> +		socket_map = cpu_map__new(str);
> +		str += strlen(str) + 1;
> +		if (!socket_map)
> +			continue;
> +		cpu_nr = socket_map->nr;
> +		for (j = 0; j < cpu_nr; j++) {
> +			if (cpu == socket_map->map[j]) {
> +				free(socket_map);
> +				return i;
> +			}
> +		}
> +		free(socket_map);
> +	}
> +
> +	return -1;
> +}
> 
> Thanks,
> Kan
> 
> > I think we need new feature that stores topology info and new interface
> > that will provide all useful mappings:
> >   idx -> cpu
> >   cpu -> core
> >   cpu -> socket
> >   cpu -> node
> > 
> > in another patchset I used new CPUMAP event:
> > https://git.kernel.org/cgit/linux/kernel/git/jolsa/perf.git/commit/?h=perf/
> > stat_script_3&id=37b7b8449aa23acdfe9dec5a7a371e91c5323da5
> > 
> > we might need both ways (new FEATURE and event) to support pipe
> > reports
> > 
> > jirka