[PATCH v4 06/16] perf tools: Support perf event alias name

Wang Nan
2015-12-08T02:27:18Z

From: He Kuang <hekuang@huawei.com>

This patch adds new bison rules for specifying an alias name to a perf
event, which allows cmdline refer to previous defined perf event through
its name. With this patch user can give alias name to a perf event using
following cmdline:

# perf record -e mypmu=cycles ...

If alias is not provided (normal case):

# perf record -e cycles ...

It will be set to event's name automatically ('cycles' in the above
example).

To allow parser refer to existing event selector, pass event list to
'struct parse_events_evlist'. perf_evlist__find_evsel_by_alias() is
introduced to get evsel through its alias.

Test result:

Before this patch:

# ./perf record -e evt=cycles usleep 10
event syntax error: 'evt=cycles'
\___ parser error
Run 'perf list' for a list of valid events
[SNIP]

After this patch:

# ./perf record -e evt=cycles usleep 10
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.012 MB perf.data (2 samples) ]

Signed-off-by: He Kuang <hekuang@huawei.com>
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
---
tools/perf/util/evlist.c | 16 ++++++++++++++++
tools/perf/util/evlist.h | 4 ++++
tools/perf/util/evsel.c | 1 +
tools/perf/util/evsel.h | 1 +
tools/perf/util/parse-events.c | 37 ++++++++++++++++++++++++++++++++-----
tools/perf/util/parse-events.h | 5 +++++
tools/perf/util/parse-events.y | 15 ++++++++++++++-
7 files changed, 73 insertions(+), 6 deletions(-)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index d1b6c20..a822823 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1737,3 +1737,19 @@ void perf_evlist__set_tracking_event(struct perf_evlist *evlist,

tracking_evsel->tracking = true;
}
+
+struct perf_evsel *
+perf_evlist__find_evsel_by_alias(struct perf_evlist *evlist,
+ const char *alias)
+{
+ struct perf_evsel *evsel;
+
+ evlist__for_each(evlist, evsel) {
+ if (!evsel->alias)
+ continue;
+ if (strcmp(alias, evsel->alias) == 0)
+ return evsel;
+ }
+
+ return NULL;
+}
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index a459fe7..4e25342 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -292,4 +292,8 @@ void perf_evlist__set_tracking_event(struct perf_evlist *evlist,
struct perf_evsel *tracking_evsel);

void perf_event_attr__set_max_precise_ip(struct perf_event_attr *attr);
+
+struct perf_evsel *
+perf_evlist__find_evsel_by_alias(struct perf_evlist *evlist, const char *alias);
+
#endif /* __PERF_EVLIST_H */
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 47f0330..8e0e6f4 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1073,6 +1073,7 @@ void perf_evsel__exit(struct perf_evsel *evsel)
thread_map__put(evsel->threads);
zfree(&evsel->group_name);
zfree(&evsel->name);
+ zfree(&evsel->alias);
perf_evsel__object.fini(evsel);
}

diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 5ded1fc..5f6dd57 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -89,6 +89,7 @@ struct perf_evsel {
int idx;
u32 ids;
char *name;
+ char *alias;
double scale;
const char *unit;
struct event_format *tp_format;
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 95775fe..484c8e4 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -653,9 +653,9 @@ parse_events_config_bpf(struct parse_events_evlist *data,
return -EINVAL;
}

- err = bpf__config_obj(obj, term, NULL, &error_pos);
+ err = bpf__config_obj(obj, term, data->evlist, &error_pos);
if (err) {
- bpf__strerror_config_obj(obj, term, NULL,
+ bpf__strerror_config_obj(obj, term, data->evlist,
&error_pos, err, errbuf,
sizeof(errbuf));
data->error->help = strdup(
@@ -1089,6 +1089,30 @@ int parse_events__modifier_group(struct list_head *list,
return parse_events__modifier_event(list, event_mod, true);
}

+int parse_events__set_event_alias(struct parse_events_evlist *data,
+ struct list_head *list,
+ const char *str,
+ void *loc_alias_)
+{
+ struct perf_evsel *evsel;
+ YYLTYPE *loc_alias = loc_alias_;
+
+ if (!str)
+ return 0;
+
+ if (!list_is_singular(list)) {
+ struct parse_events_error *err = data->error;
+
+ err->idx = loc_alias->first_column;
+ err->str = strdup("One alias can be applied to one event only");
+ return -EINVAL;
+ }
+
+ evsel = list_first_entry(list, struct perf_evsel, node);
+ evsel->alias = strdup(str);
+ return evsel->alias ? 0 : -ENOMEM;
+}
+
void parse_events__set_leader(char *name, struct list_head *list)
{
struct perf_evsel *leader;
@@ -1281,6 +1305,8 @@ int parse_events_name(struct list_head *list, char *name)
__evlist__for_each(list, evsel) {
if (!evsel->name)
evsel->name = strdup(name);
+ if (!evsel->alias)
+ evsel->alias = strdup(name);
}

return 0;
@@ -1442,9 +1468,10 @@ int parse_events(struct perf_evlist *evlist, const char *str,
struct parse_events_error *err)
{
struct parse_events_evlist data = {
- .list = LIST_HEAD_INIT(data.list),
- .idx = evlist->nr_entries,
- .error = err,
+ .list = LIST_HEAD_INIT(data.list),
+ .idx = evlist->nr_entries,
+ .error = err,
+ .evlist = evlist,
};
int ret;

diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index 84694f3..20ad3c2 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -98,6 +98,7 @@ struct parse_events_evlist {
int idx;
int nr_groups;
struct parse_events_error *error;
+ struct perf_evlist *evlist;
};

struct parse_events_terms {
@@ -171,4 +172,8 @@ extern int is_valid_tracepoint(const char *event_string);
int valid_event_mount(const char *eventfs);
char *parse_events_formats_error_string(char *additional_terms);

+int parse_events__set_event_alias(struct parse_events_evlist *data,
+ struct list_head *list,
+ const char *str,
+ void *loc_alias_);
#endif /* __PERF_PARSE_EVENTS_H */
diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
index 8992d16..c3cbd7a 100644
--- a/tools/perf/util/parse-events.y
+++ b/tools/perf/util/parse-events.y
@@ -77,6 +77,7 @@ static inc_group_count(struct list_head *list,
%type event_bpf_file
%type event_def
%type event_mod
+%type event_alias
%type event_name
%type event
%type events
@@ -193,13 +194,25 @@ event_name PE_MODIFIER_EVENT
event_name

event_name:
-PE_EVENT_NAME event_def
+PE_EVENT_NAME event_alias
{
ABORT_ON(parse_events_name($2, $1));
free($1);
$$ = $2;
}
|
+event_alias
+
+event_alias:
+PE_NAME '=' event_def
+{
+ struct list_head *list = $3;
+ struct parse_events_evlist *data = _data;
+
+ ABORT_ON(parse_events__set_event_alias(data, list, $1, &@1));
+ $$ = list;
+}
+|
event_def

event_def: event_pmu |
--
1.8.3.4