[PATCH v3 10/11] perf evlist: Remove nr_groups

From: Ian Rogers
Date: Wed Mar 08 2023 - 03:20:16 EST


Maintaining the number of groups during event parsing is problematic
and since changing to sort/regroup events can only be computed by a
linear pass over the evlist. As the value is generally only used in
tests, rather than hold it in a variable compute it by passing over
the evlist when necessary.

This change highlights that libpfm's counting of groups with a single
entry disagreed with regular event parsing. The libpfm tests are
updated accordingly.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/lib/perf/evlist.c | 18 +++++++++++++++++-
tools/lib/perf/include/internal/evlist.h | 1 -
tools/lib/perf/include/perf/evlist.h | 1 +
tools/perf/builtin-record.c | 2 +-
tools/perf/builtin-report.c | 2 +-
tools/perf/tests/bpf.c | 1 -
tools/perf/tests/parse-events.c | 22 +++++++++++-----------
tools/perf/tests/pfm.c | 12 ++++++------
tools/perf/util/evlist.c | 2 +-
tools/perf/util/evlist.h | 6 ++++++
tools/perf/util/header.c | 3 +--
tools/perf/util/parse-events.c | 1 -
tools/perf/util/parse-events.h | 1 -
tools/perf/util/parse-events.y | 10 ----------
tools/perf/util/pfm.c | 1 -
15 files changed, 45 insertions(+), 38 deletions(-)

diff --git a/tools/lib/perf/evlist.c b/tools/lib/perf/evlist.c
index 2d6121e89ccb..81e8b5fcd8ba 100644
--- a/tools/lib/perf/evlist.c
+++ b/tools/lib/perf/evlist.c
@@ -703,7 +703,23 @@ void perf_evlist__set_leader(struct perf_evlist *evlist)
struct perf_evsel *first = list_entry(evlist->entries.next,
struct perf_evsel, node);

- evlist->nr_groups = evlist->nr_entries > 1 ? 1 : 0;
__perf_evlist__set_leader(&evlist->entries, first);
}
}
+
+int perf_evlist__nr_groups(struct perf_evlist *evlist)
+{
+ struct perf_evsel *evsel;
+ int nr_groups = 0;
+
+ perf_evlist__for_each_evsel(evlist, evsel) {
+ /*
+ * evsels by default have a nr_members of 1, and they are their
+ * own leader. If the nr_members is >1 then this is an
+ * indication of a group.
+ */
+ if (evsel->leader == evsel && evsel->nr_members > 1)
+ nr_groups++;
+ }
+ return nr_groups;
+}
diff --git a/tools/lib/perf/include/internal/evlist.h b/tools/lib/perf/include/internal/evlist.h
index 850f07070036..3339bc2f1765 100644
--- a/tools/lib/perf/include/internal/evlist.h
+++ b/tools/lib/perf/include/internal/evlist.h
@@ -17,7 +17,6 @@ struct perf_mmap_param;
struct perf_evlist {
struct list_head entries;
int nr_entries;
- int nr_groups;
bool has_user_cpus;
bool needs_map_propagation;
/**
diff --git a/tools/lib/perf/include/perf/evlist.h b/tools/lib/perf/include/perf/evlist.h
index 9ca399d49bb4..e894b770779e 100644
--- a/tools/lib/perf/include/perf/evlist.h
+++ b/tools/lib/perf/include/perf/evlist.h
@@ -47,4 +47,5 @@ LIBPERF_API struct perf_mmap *perf_evlist__next_mmap(struct perf_evlist *evlist,
(pos) = perf_evlist__next_mmap((evlist), (pos), overwrite))

LIBPERF_API void perf_evlist__set_leader(struct perf_evlist *evlist);
+LIBPERF_API int perf_evlist__nr_groups(struct perf_evlist *evlist);
#endif /* __LIBPERF_EVLIST_H */
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index a0870c076dc0..234b371b7b9f 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -2474,7 +2474,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
rec->tool.ordered_events = false;
}

- if (!rec->evlist->core.nr_groups)
+ if (evlist__nr_groups(rec->evlist) == 0)
perf_header__clear_feat(&session->header, HEADER_GROUP_DESC);

if (data->is_pipe) {
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 2ee2ecca208e..6400615b5e98 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -1481,7 +1481,7 @@ int cmd_report(int argc, const char **argv)

setup_forced_leader(&report, session->evlist);

- if (symbol_conf.group_sort_idx && !session->evlist->core.nr_groups) {
+ if (symbol_conf.group_sort_idx && evlist__nr_groups(session->evlist) == 0) {
parse_options_usage(NULL, options, "group-sort-idx", 0);
ret = -EINVAL;
goto error;
diff --git a/tools/perf/tests/bpf.c b/tools/perf/tests/bpf.c
index ae9223f27cfb..8beb46066034 100644
--- a/tools/perf/tests/bpf.c
+++ b/tools/perf/tests/bpf.c
@@ -153,7 +153,6 @@ static int do_test(struct bpf_object *obj, int (*func)(void),
}

evlist__splice_list_tail(evlist, &parse_state.list);
- evlist->core.nr_groups = parse_state.nr_groups;

evlist__config(evlist, &opts, NULL);

diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c
index 71a5cb343311..ffa6f0a90741 100644
--- a/tools/perf/tests/parse-events.c
+++ b/tools/perf/tests/parse-events.c
@@ -53,7 +53,7 @@ static int test__checkevent_tracepoint(struct evlist *evlist)
struct evsel *evsel = evlist__first(evlist);

TEST_ASSERT_VAL("wrong number of entries", 1 == evlist->core.nr_entries);
- TEST_ASSERT_VAL("wrong number of groups", 0 == evlist->core.nr_groups);
+ TEST_ASSERT_VAL("wrong number of groups", 0 == evlist__nr_groups(evlist));
TEST_ASSERT_VAL("wrong type", PERF_TYPE_TRACEPOINT == evsel->core.attr.type);
TEST_ASSERT_VAL("wrong sample_type",
PERF_TP_SAMPLE_TYPE == evsel->core.attr.sample_type);
@@ -66,7 +66,7 @@ static int test__checkevent_tracepoint_multi(struct evlist *evlist)
struct evsel *evsel;

TEST_ASSERT_VAL("wrong number of entries", evlist->core.nr_entries > 1);
- TEST_ASSERT_VAL("wrong number of groups", 0 == evlist->core.nr_groups);
+ TEST_ASSERT_VAL("wrong number of groups", 0 == evlist__nr_groups(evlist));

evlist__for_each_entry(evlist, evsel) {
TEST_ASSERT_VAL("wrong type",
@@ -677,7 +677,7 @@ static int test__group1(struct evlist *evlist)
struct evsel *evsel, *leader;

TEST_ASSERT_VAL("wrong number of entries", 2 == evlist->core.nr_entries);
- TEST_ASSERT_VAL("wrong number of groups", 1 == evlist->core.nr_groups);
+ TEST_ASSERT_VAL("wrong number of groups", 1 == evlist__nr_groups(evlist));

/* instructions:k */
evsel = leader = evlist__first(evlist);
@@ -719,7 +719,7 @@ static int test__group2(struct evlist *evlist)
struct evsel *evsel, *leader;

TEST_ASSERT_VAL("wrong number of entries", 3 == evlist->core.nr_entries);
- TEST_ASSERT_VAL("wrong number of groups", 1 == evlist->core.nr_groups);
+ TEST_ASSERT_VAL("wrong number of groups", 1 == evlist__nr_groups(evlist));

/* faults + :ku modifier */
evsel = leader = evlist__first(evlist);
@@ -775,7 +775,7 @@ static int test__group3(struct evlist *evlist __maybe_unused)
struct evsel *evsel, *leader;

TEST_ASSERT_VAL("wrong number of entries", 5 == evlist->core.nr_entries);
- TEST_ASSERT_VAL("wrong number of groups", 2 == evlist->core.nr_groups);
+ TEST_ASSERT_VAL("wrong number of groups", 2 == evlist__nr_groups(evlist));

/* group1 syscalls:sys_enter_openat:H */
evsel = leader = evlist__first(evlist);
@@ -868,7 +868,7 @@ static int test__group4(struct evlist *evlist __maybe_unused)
struct evsel *evsel, *leader;

TEST_ASSERT_VAL("wrong number of entries", 2 == evlist->core.nr_entries);
- TEST_ASSERT_VAL("wrong number of groups", 1 == evlist->core.nr_groups);
+ TEST_ASSERT_VAL("wrong number of groups", 1 == evlist__nr_groups(evlist));

/* cycles:u + p */
evsel = leader = evlist__first(evlist);
@@ -912,7 +912,7 @@ static int test__group5(struct evlist *evlist __maybe_unused)
struct evsel *evsel, *leader;

TEST_ASSERT_VAL("wrong number of entries", 5 == evlist->core.nr_entries);
- TEST_ASSERT_VAL("wrong number of groups", 2 == evlist->core.nr_groups);
+ TEST_ASSERT_VAL("wrong number of groups", 2 == evlist__nr_groups(evlist));

/* cycles + G */
evsel = leader = evlist__first(evlist);
@@ -998,7 +998,7 @@ static int test__group_gh1(struct evlist *evlist)
struct evsel *evsel, *leader;

TEST_ASSERT_VAL("wrong number of entries", 2 == evlist->core.nr_entries);
- TEST_ASSERT_VAL("wrong number of groups", 1 == evlist->core.nr_groups);
+ TEST_ASSERT_VAL("wrong number of groups", 1 == evlist__nr_groups(evlist));

/* cycles + :H group modifier */
evsel = leader = evlist__first(evlist);
@@ -1038,7 +1038,7 @@ static int test__group_gh2(struct evlist *evlist)
struct evsel *evsel, *leader;

TEST_ASSERT_VAL("wrong number of entries", 2 == evlist->core.nr_entries);
- TEST_ASSERT_VAL("wrong number of groups", 1 == evlist->core.nr_groups);
+ TEST_ASSERT_VAL("wrong number of groups", 1 == evlist__nr_groups(evlist));

/* cycles + :G group modifier */
evsel = leader = evlist__first(evlist);
@@ -1078,7 +1078,7 @@ static int test__group_gh3(struct evlist *evlist)
struct evsel *evsel, *leader;

TEST_ASSERT_VAL("wrong number of entries", 2 == evlist->core.nr_entries);
- TEST_ASSERT_VAL("wrong number of groups", 1 == evlist->core.nr_groups);
+ TEST_ASSERT_VAL("wrong number of groups", 1 == evlist__nr_groups(evlist));

/* cycles:G + :u group modifier */
evsel = leader = evlist__first(evlist);
@@ -1118,7 +1118,7 @@ static int test__group_gh4(struct evlist *evlist)
struct evsel *evsel, *leader;

TEST_ASSERT_VAL("wrong number of entries", 2 == evlist->core.nr_entries);
- TEST_ASSERT_VAL("wrong number of groups", 1 == evlist->core.nr_groups);
+ TEST_ASSERT_VAL("wrong number of groups", 1 == evlist__nr_groups(evlist));

/* cycles:G + :uG group modifier */
evsel = leader = evlist__first(evlist);
diff --git a/tools/perf/tests/pfm.c b/tools/perf/tests/pfm.c
index 71b76deb1f92..2e38dfa34b6c 100644
--- a/tools/perf/tests/pfm.c
+++ b/tools/perf/tests/pfm.c
@@ -76,7 +76,7 @@ static int test__pfm_events(struct test_suite *test __maybe_unused,
count_pfm_events(&evlist->core),
table[i].nr_events);
TEST_ASSERT_EQUAL(table[i].events,
- evlist->core.nr_groups,
+ evlist__nr_groups(evlist),
0);

evlist__delete(evlist);
@@ -103,22 +103,22 @@ static int test__pfm_group(struct test_suite *test __maybe_unused,
{
.events = "{instructions}",
.nr_events = 1,
- .nr_groups = 1,
+ .nr_groups = 0,
},
{
.events = "{instructions},{}",
.nr_events = 1,
- .nr_groups = 1,
+ .nr_groups = 0,
},
{
.events = "{},{instructions}",
.nr_events = 1,
- .nr_groups = 1,
+ .nr_groups = 0,
},
{
.events = "{instructions},{instructions}",
.nr_events = 2,
- .nr_groups = 2,
+ .nr_groups = 0,
},
{
.events = "{instructions,cycles},{instructions,cycles}",
@@ -161,7 +161,7 @@ static int test__pfm_group(struct test_suite *test __maybe_unused,
count_pfm_events(&evlist->core),
table[i].nr_events);
TEST_ASSERT_EQUAL(table[i].events,
- evlist->core.nr_groups,
+ evlist__nr_groups(evlist),
table[i].nr_groups);

evlist__delete(evlist);
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 817df2504a1e..a5f406c468f8 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1777,7 +1777,7 @@ bool evlist__exclude_kernel(struct evlist *evlist)
*/
void evlist__force_leader(struct evlist *evlist)
{
- if (!evlist->core.nr_groups) {
+ if (evlist__nr_groups(evlist) == 0) {
struct evsel *leader = evlist__first(evlist);

evlist__set_leader(evlist);
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index d89d8f92802b..46cf402add93 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -9,6 +9,7 @@
#include <api/fd/array.h>
#include <internal/evlist.h>
#include <internal/evsel.h>
+#include <perf/evlist.h>
#include "events_stats.h"
#include "evsel.h"
#include <pthread.h>
@@ -255,6 +256,11 @@ static inline struct evsel *evlist__last(struct evlist *evlist)
return container_of(evsel, struct evsel, core);
}

+static inline int evlist__nr_groups(struct evlist *evlist)
+{
+ return perf_evlist__nr_groups(&evlist->core);
+}
+
int evlist__strerror_open(struct evlist *evlist, int err, char *buf, size_t size);
int evlist__strerror_mmap(struct evlist *evlist, int err, char *buf, size_t size);

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 404d816ca124..276870221ce0 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -786,7 +786,7 @@ static int write_pmu_mappings(struct feat_fd *ff,
static int write_group_desc(struct feat_fd *ff,
struct evlist *evlist)
{
- u32 nr_groups = evlist->core.nr_groups;
+ u32 nr_groups = evlist__nr_groups(evlist);
struct evsel *evsel;
int ret;

@@ -2807,7 +2807,6 @@ static int process_group_desc(struct feat_fd *ff, void *data __maybe_unused)
* Rebuild group relationship based on the group_desc
*/
session = container_of(ff->ph, struct perf_session, header);
- session->evlist->core.nr_groups = nr_groups;

i = nr = 0;
evlist__for_each_entry(session->evlist, evsel) {
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 93a90651266f..9ec3c1dc81e0 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -2260,7 +2260,6 @@ int __parse_events(struct evlist *evlist, const char *str,
if (!ret) {
struct evsel *last;

- evlist->core.nr_groups += parse_state.nr_groups;
last = evlist__last(evlist);
last->cmdline_group_boundary = true;

diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index fdac44dc696b..767ad1729228 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -122,7 +122,6 @@ struct parse_events_error {
struct parse_events_state {
struct list_head list;
int idx;
- int nr_groups;
struct parse_events_error *error;
struct evlist *evlist;
struct list_head *terms;
diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
index f1b153c72d67..3a04602d2982 100644
--- a/tools/perf/util/parse-events.y
+++ b/tools/perf/util/parse-events.y
@@ -49,14 +49,6 @@ static void free_list_evsel(struct list_head* list_evsel)
free(list_evsel);
}

-static void inc_group_count(struct list_head *list,
- struct parse_events_state *parse_state)
-{
- /* Count groups only have more than 1 members */
- if (!list_is_last(list->next, list))
- parse_state->nr_groups++;
-}
-
%}

%token PE_START_EVENTS PE_START_TERMS
@@ -201,7 +193,6 @@ PE_NAME '{' events '}'
{
struct list_head *list = $3;

- inc_group_count(list, _parse_state);
/* Takes ownership of $1. */
parse_events__set_leader($1, list);
$$ = list;
@@ -211,7 +202,6 @@ PE_NAME '{' events '}'
{
struct list_head *list = $2;

- inc_group_count(list, _parse_state);
parse_events__set_leader(NULL, list);
$$ = list;
}
diff --git a/tools/perf/util/pfm.c b/tools/perf/util/pfm.c
index b59ba825ddc9..6c11914c179f 100644
--- a/tools/perf/util/pfm.c
+++ b/tools/perf/util/pfm.c
@@ -112,7 +112,6 @@ int parse_libpfm_events_option(const struct option *opt, const char *str,
"cannot close a non-existing event group\n");
goto error;
}
- evlist->core.nr_groups++;
grp_leader = NULL;
grp_evt = -1;
}
--
2.40.0.rc0.216.gc4246ad0f0-goog