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perf evlist: Default to syswide target when no thread/cpu maps set

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If all a tool wants is to do system wide event monitoring, there is no
more the need to setup thread_map and cpu_map objects, just call
perf_evlist__open() and it will do create one fd per CPU monitoring all
threads.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-poovolkigu72brx4783uq4cf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Arnaldo Carvalho de Melo 2014-10-10 15:55:15 -03:00
parent 1aaf63b1ee
commit 4112eb1899
1 changed files with 40 additions and 0 deletions
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40
tools/perf/util/evlist.c
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@ -1175,11 +1175,51 @@ void perf_evlist__close(struct perf_evlist *evlist)
}
}
static int perf_evlist__create_syswide_maps(struct perf_evlist *evlist)
{
int err = -ENOMEM;
/*
* Try reading /sys/devices/system/cpu/online to get
* an all cpus map.
*
* FIXME: -ENOMEM is the best we can do here, the cpu_map
* code needs an overhaul to properly forward the
* error, and we may not want to do that fallback to a
* default cpu identity map :-\
*/
evlist->cpus = cpu_map__new(NULL);
if (evlist->cpus == NULL)
goto out;
evlist->threads = thread_map__new_dummy();
if (evlist->threads == NULL)
goto out_free_cpus;
err = 0;
out:
return err;
out_free_cpus:
cpu_map__delete(evlist->cpus);
evlist->cpus = NULL;
goto out;
}
int perf_evlist__open(struct perf_evlist *evlist)
{
struct perf_evsel *evsel;
int err;
/*
* Default: one fd per CPU, all threads, aka systemwide
* as sys_perf_event_open(cpu = -1, thread = -1) is EINVAL
*/
if (evlist->threads == NULL && evlist->cpus == NULL) {
err = perf_evlist__create_syswide_maps(evlist);
if (err < 0)
goto out_err;
}
perf_evlist__update_id_pos(evlist);
evlist__for_each(evlist, evsel) {