Ok,
turns out perf-list(1) already talks about it in the "EVENT GROUPS"
section. How about this then:
---
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index a02f2e965628..2d18283574db 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -146,6 +146,7 @@ static aggr_get_id_t aggr_get_id;
static bool append_file;
static const char *output_name;
static int output_fd;
+static int print_free_counters_hint;
struct perf_stat {
bool record;
@@ -1109,6 +1110,9 @@ static void printout(int id, int nr, struct perf_evsel
*counter, double uval,
counter->supported ? CNTR_NOT_COUNTED :
CNTR_NOT_SUPPORTED,
csv_sep);
+ if (counter->supported)
+ print_free_counters_hint = 1;
+
fprintf(stat_config.output, "%-*s%s",
csv_output ? 0 : unit_width,
counter->unit, csv_sep);
@@ -1476,7 +1480,13 @@ static void print_footer(void)
print_noise_pct(stddev_stats(&walltime_nsecs_stats),
avg_stats(&walltime_nsecs_stats));
}
+
fprintf(output, "\n\n");
+
+ if (print_free_counters_hint)
+ fprintf(output,
+"Some events couldn't be scheduled. Consider freeing some counters by
disabling the NMI watchdog temporarily, \n"
+"for example. See perf-list(1) manpage.\n");
}
static void print_counters(struct timespec *ts, int argc, const char **argv)
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
