[PATCH 39/86] perf evsel: Allow asking for max precise_ip in new_cycles()

Arnaldo Carvalho de Melo
2017-07-19T14:34:04Z

From: Arnaldo Carvalho de Melo <acme@redhat.com>

There are cases where we want to leave attr.precise_ip as zero, such
as when using 'perf record --no-samples', where this would make the
kernel return -EINVAL.

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: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-4zq1udecxa51gsapyfwej5fj@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/evlist.c | 2 +-
tools/perf/util/evsel.c | 7 +++++--
tools/perf/util/evsel.h | 2 +-
3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 46c0faf6c502..f51c3314015c 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -244,7 +244,7 @@ void perf_event_attr__set_max_precise_ip(struct perf_event_attr *attr)

int perf_evlist__add_default(struct perf_evlist *evlist)
{
- struct perf_evsel *evsel = perf_evsel__new_cycles();
+ struct perf_evsel *evsel = perf_evsel__new_cycles(true);

if (evsel == NULL)
return -ENOMEM;
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 0e4cd6092564..df567e478a0e 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -268,7 +268,7 @@ struct perf_evsel *perf_evsel__new_idx(struct perf_event_attr *attr, int idx)
return evsel;
}

-struct perf_evsel *perf_evsel__new_cycles(void)
+struct perf_evsel *perf_evsel__new_cycles(bool precise)
{
struct perf_event_attr attr = {
.type = PERF_TYPE_HARDWARE,
@@ -278,6 +278,9 @@ struct perf_evsel *perf_evsel__new_cycles(void)
struct perf_evsel *evsel;

event_attr_init(&attr);
+
+ if (!precise)
+ goto new_event;
/*
* Unnamed union member, not supported as struct member named
* initializer in older compilers such as gcc 4.4.7
@@ -292,7 +295,7 @@ struct perf_evsel *perf_evsel__new_cycles(void)
* to kick in when we return and before perf_evsel__open() is called.
*/
attr.sample_period = 0;
-
+new_event:
evsel = perf_evsel__new(&attr);
if (evsel == NULL)
goto out;
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 219ad0cdb9f4..fb40ca3c6519 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -185,7 +185,7 @@ static inline struct perf_evsel *perf_evsel__newtp(const char *sys, const char *
return perf_evsel__newtp_idx(sys, name, 0);
}

-struct perf_evsel *perf_evsel__new_cycles(void);
+struct perf_evsel *perf_evsel__new_cycles(bool precise);

struct event_format *event_format__new(const char *sys, const char *name);

--
2.9.4