perf tools: Force uncore events to system wide monitoring

Make system wide (-a) the default option if no target was specified and
one of following conditions is met:

  - there's no workload specified (current behaviour)
  - there is workload specified but all requested
    events are system wide ones

Mixed events core/uncore with workload:

  $ perf stat -e 'uncore_cbox_0/clockticks/,cycles' sleep 1

   Performance counter stats for 'sleep 1':

     <not supported>      uncore_cbox_0/clockticks/
             980,489      cycles

         1.000897406 seconds time elapsed

Uncore event with workload:

  $ perf stat -e 'uncore_cbox_0/clockticks/' sleep 1

   Performance counter stats for 'system wide':

  281,473,897,192,670      uncore_cbox_0/clockticks/

         1.000833784 seconds time elapsed

Committer note:

When testing I realized the default case for !root, i.e. no events
passed via -e, was broke by v2 of this patch, reported and after a
patch provided by Jiri it is back working:

  [acme@jouet linux]$ perf stat usleep 1

   Performance counter stats for 'usleep 1':

         0.401335      task-clock:u (msec)     #   0.297 CPUs utilized
                0      context-switches:u      #   0.000 K/sec
                0      cpu-migrations:u        #   0.000 K/sec
               48      page-faults:u           #   0.120 M/sec
          458,146      cycles:u                #   1.142 GHz
          245,113      instructions:u          #   0.54  insn per cycle
           47,991      branches:u              # 119.578 M/sec
            4,022      branch-misses:u         #   8.38% of all branches

      0.001350029 seconds time elapsed

  [acme@jouet linux]$

Suggested-and-Tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20170227094818.GA12764@krava
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Jiri Olsa 2017-02-27 10:48:18 +01:00 committed by Arnaldo Carvalho de Melo
parent d0e02579c2
commit e3ba76deef
2 changed files with 33 additions and 5 deletions

View File

@ -2350,6 +2350,35 @@ static int __cmd_report(int argc, const char **argv)
return 0;
}
static void setup_system_wide(int forks)
{
/*
* Make system wide (-a) the default target if
* no target was specified and one of following
* conditions is met:
*
* - there's no workload specified
* - there is workload specified but all requested
* events are system wide events
*/
if (!target__none(&target))
return;
if (!forks)
target.system_wide = true;
else {
struct perf_evsel *counter;
evlist__for_each_entry(evsel_list, counter) {
if (!counter->system_wide)
return;
}
if (evsel_list->nr_entries)
target.system_wide = true;
}
}
int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
{
const char * const stat_usage[] = {
@ -2456,9 +2485,7 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
} else if (big_num_opt == 0) /* User passed --no-big-num */
big_num = false;
/* Make system wide (-a) the default target. */
if (!argc && target__none(&target))
target.system_wide = true;
setup_system_wide(argc);
if (run_count < 0) {
pr_err("Run count must be a positive number\n");

View File

@ -316,8 +316,9 @@ __add_event(struct list_head *list, int *idx,
return NULL;
(*idx)++;
evsel->cpus = cpu_map__get(cpus);
evsel->own_cpus = cpu_map__get(cpus);
evsel->cpus = cpu_map__get(cpus);
evsel->own_cpus = cpu_map__get(cpus);
evsel->system_wide = !!cpus;
if (name)
evsel->name = strdup(name);