[PATCHv2 01/15] perf tools: Fix -n option

[Jiri Olsa <jolsa@redhat.com>]

On Mon, Jul 03, 2017 at 11:57:39AM -0300, Arnaldo Carvalho de Melo wrote:
> Em Mon, Jul 03, 2017 at 04:50:16PM +0200, Jiri Olsa escreveu:
> > The kernel fails to add a non sampling event event
> > with having precise_ip set.
> > 
> > Make sure the precise_ip is 0 when using -n option
> > to create non sampling event in record.
> 
> Ok, but how could that happen? What was the scenario? Which command? Can
> you provide a command line that causes the problem?

[jolsa@krava perf]$ ./perf record -e cycles:ppp -n ls
Lowering default frequency rate to 3000.
Please consider tweaking /proc/sys/kernel/perf_event_max_sample_rate.
Error:
The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (cycles:pppu).
/bin/dmesg may provide additional information.
No CONFIG_PERF_EVENTS=y kernel support configured?

v2 attached, thanks
jirka


---
The kernel fails to add a non sampling event event
with having precise_ip set, like:

  $ perf record -e cycles:ppp -n ls
  Error:
  The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (cycles:pppu).
  /bin/dmesg may provide additional information.
  No CONFIG_PERF_EVENTS=y kernel support configured?

Make sure the precise_ip is 0 when using -n option
to create non sampling event in record.

Link: http://lkml.kernel.org/n/tip-l513fzc1houvu7tl1bo5y65y@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/perf/util/evsel.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 6f4882f8d61f..915fe3cd6544 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -890,8 +890,10 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts,
 		attr->sample_period = 0;
 	}
 
-	if (opts->no_samples)
+	if (opts->no_samples) {
 		attr->sample_freq = 0;
+		attr->precise_ip = 0;
+	}
 
 	if (opts->inherit_stat)
 		attr->inherit_stat = 1;
-- 
2.9.4