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

From: Jiri Olsa
Date: Sun Aug 23 2015 - 18:00:23 EST


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
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