[PATCH v2 4/6] perf test pmu: Add an eagerly loaded event test

Ian Rogers
2024-04-23T03:17:48Z

Allow events/aliases to be eagerly loaded for a PMU. Factor out the
pmu_aliases_parse to allow this. Parse a test event and check it
configures the attribute as expected. There is overlap with the
parse-events tests, but this test is done with a PMU created in a temp
directory and doesn't rely on PMUs in sysfs.

Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/tests/pmu.c | 72 ++++++++++++++++++++++++++++++++++++++++++
tools/perf/util/pmu.c | 69 ++++++++++++++++++++++++++++------------
2 files changed, 120 insertions(+), 21 deletions(-)

diff --git a/tools/perf/tests/pmu.c b/tools/perf/tests/pmu.c
index 6b2d9adcc583..f4e9a39534cb 100644
--- a/tools/perf/tests/pmu.c
+++ b/tools/perf/tests/pmu.c
@@ -1,4 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
+#include "evlist.h"
+#include "evsel.h"
#include "parse-events.h"
#include "pmu.h"
#include "tests.h"
@@ -54,6 +56,9 @@ static struct perf_pmu *test_pmu_get(char *dir, size_t sz)
{ "krava22", "config2:8,18,48,58\n", },
{ "krava23", "config2:28-29,38\n", },
};
+ const char *test_event = "krava01=15,krava02=170,krava03=1,krava11=27,krava12=1,"
+ "krava13=2,krava21=119,krava22=11,krava23=2\n";
+
char name[PATH_MAX];
int dirfd, file;
struct perf_pmu *pmu = NULL;
@@ -110,6 +115,19 @@ static struct perf_pmu *test_pmu_get(char *dir, size_t sz)
close(file);
}

+ /* Create test event. */
+ if (mkdirat(dirfd, "perf-pmu-test/events", 0755) < 0) {
+ pr_err("Failed to mkdir PMU events directory\n");
+ goto err_out;
+ }
+ file = openat(dirfd, "perf-pmu-test/events/test-event", O_WRONLY | O_CREAT, 0600);
+ if (!file) {
+ pr_err("Failed to open for writing file \"type\"\n");
+ goto err_out;
+ }
+ write(file, test_event, strlen(test_event));
+ close(file);
+
/* Make the PMU reading the files created above. */
pmu = perf_pmus__add_test_pmu(dirfd, "perf-pmu-test");
if (!pmu)
@@ -170,8 +188,62 @@ static int test__pmu_format(struct test_suite *test __maybe_unused, int subtest
return ret;
}

+static int test__pmu_events(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
+{
+ char dir[PATH_MAX];
+ struct parse_events_error err;
+ struct evlist *evlist;
+ struct evsel *evsel;
+ struct perf_event_attr *attr;
+ int ret;
+ struct perf_pmu *pmu = test_pmu_get(dir, sizeof(dir));
+ const char *event = "perf-pmu-test/test-event/";
+
+
+ if (!pmu)
+ return TEST_FAIL;
+
+ evlist = evlist__new();
+ if (evlist == NULL) {
+ pr_err("Failed allocation");
+ goto err_out;
+ }
+ parse_events_error__init(&err);
+ ret = parse_events(evlist, event, &err);
+ if (ret) {
+ pr_debug("failed to parse event '%s', err %d\n", event, ret);
+ parse_events_error__print(&err, event);
+ ret = TEST_FAIL;
+ if (parse_events_error__contains(&err, "can't access trace events"))
+ ret = TEST_SKIP;
+ goto err_out;
+ }
+ evsel = evlist__first(evlist);
+ attr = &evsel->core.attr;
+ if (attr->config != 0xc00000000002a823) {
+ pr_err("Unexpected config value %llx\n", attr->config);
+ goto err_out;
+ }
+ if (attr->config1 != 0x8000400000000145) {
+ pr_err("Unexpected config1 value %llx\n", attr->config1);
+ goto err_out;
+ }
+ if (attr->config2 != 0x0400000020041d07) {
+ pr_err("Unexpected config2 value %llx\n", attr->config2);
+ goto err_out;
+ }
+
+ ret = TEST_OK;
+err_out:
+ parse_events_error__exit(&err);
+ evlist__delete(evlist);
+ test_pmu_put(dir, pmu);
+ return ret;
+}
+
static struct test_case tests__pmu[] = {
TEST_CASE("Parsing with PMU format directory", pmu_format),
+ TEST_CASE("Parsing with PMU event", pmu_events),
{ .name = NULL, }
};

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index b86ce9535088..40f3b5bd8260 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -597,33 +597,18 @@ static inline bool pmu_alias_info_file(const char *name)
* Reading the pmu event aliases definition, which should be located at:
* /sys/bus/event_source/devices/<dev>/events as sysfs group attributes.
*/
-static int pmu_aliases_parse(struct perf_pmu *pmu)
+static int __pmu_aliases_parse(struct perf_pmu *pmu, int events_dir_fd)
{
- char path[PATH_MAX];
struct dirent *evt_ent;
DIR *event_dir;
- size_t len;
- int fd, dir_fd;

- len = perf_pmu__event_source_devices_scnprintf(path, sizeof(path));
- if (!len)
- return 0;
- scnprintf(path + len, sizeof(path) - len, "%s/events", pmu->name);
-
- dir_fd = open(path, O_DIRECTORY);
- if (dir_fd == -1) {
- pmu->sysfs_aliases_loaded = true;
- return 0;
- }
-
- event_dir = fdopendir(dir_fd);
- if (!event_dir){
- close (dir_fd);
+ event_dir = fdopendir(events_dir_fd);
+ if (!event_dir)
return -EINVAL;
- }

while ((evt_ent = readdir(event_dir))) {
char *name = evt_ent->d_name;
+ int fd;
FILE *file;

if (!strcmp(name, ".") || !strcmp(name, ".."))
@@ -635,7 +620,7 @@ static int pmu_aliases_parse(struct perf_pmu *pmu)
if (pmu_alias_info_file(name))
continue;

- fd = openat(dir_fd, name, O_RDONLY);
+ fd = openat(events_dir_fd, name, O_RDONLY);
if (fd == -1) {
pr_debug("Cannot open %s\n", name);
continue;
@@ -653,11 +638,50 @@ static int pmu_aliases_parse(struct perf_pmu *pmu)
}

closedir(event_dir);
- close (dir_fd);
pmu->sysfs_aliases_loaded = true;
return 0;
}

+static int pmu_aliases_parse(struct perf_pmu *pmu)
+{
+ char path[PATH_MAX];
+ size_t len;
+ int events_dir_fd, ret;
+
+ if (pmu->sysfs_aliases_loaded)
+ return 0;
+
+ len = perf_pmu__event_source_devices_scnprintf(path, sizeof(path));
+ if (!len)
+ return 0;
+ scnprintf(path + len, sizeof(path) - len, "%s/events", pmu->name);
+
+ events_dir_fd = open(path, O_DIRECTORY);
+ if (events_dir_fd == -1) {
+ pmu->sysfs_aliases_loaded = true;
+ return 0;
+ }
+ ret = __pmu_aliases_parse(pmu, events_dir_fd);
+ close(events_dir_fd);
+ return ret;
+}
+
+static int pmu_aliases_parse_eager(struct perf_pmu *pmu, int sysfs_fd)
+{
+ char path[FILENAME_MAX + 7];
+ int ret, events_dir_fd;
+
+ scnprintf(path, sizeof(path), "%s/events", pmu->name);
+ events_dir_fd = openat(sysfs_fd, path, O_DIRECTORY, 0);
+ if (events_dir_fd == -1) {
+ pmu->sysfs_aliases_loaded = true;
+ return 0;
+ }
+ ret = __pmu_aliases_parse(pmu, events_dir_fd);
+ close(events_dir_fd);
+ return ret;
+}
+
static int pmu_alias_terms(struct perf_pmu_alias *alias, int err_loc, struct list_head *terms)
{
struct parse_events_term *term, *cloned;
@@ -1042,6 +1066,9 @@ struct perf_pmu *perf_pmu__lookup(struct list_head *pmus, int dirfd, const char

perf_pmu__arch_init(pmu);

+ if (eager_load)
+ pmu_aliases_parse_eager(pmu, dirfd);
+
return pmu;
err:
zfree(&pmu->name);
--
2.44.0.769.g3c40516874-goog