[PATCH v1 20/25] perf pmu: Cache json events table

From: Ian Rogers
Date: Wed Aug 23 2023 - 06:15:43 EST


Cache the json events table so that finding it isn't done per
event/alias. Change the events table find so that when the PMU is
given, if the PMU has no json events return null. Update usage to
always use the PMU variable.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/pmu-events/jevents.py | 14 ++++++++++++--
tools/perf/tests/pmu-events.c | 2 ++
tools/perf/util/pmu.c | 17 ++++++++---------
tools/perf/util/pmu.h | 4 ++++
4 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py
index 991fcf6cca64..f07864fabd54 100755
--- a/tools/perf/pmu-events/jevents.py
+++ b/tools/perf/pmu-events/jevents.py
@@ -948,7 +948,7 @@ const struct pmu_events_table *perf_pmu__find_events_table(struct perf_pmu *pmu)
{
const struct pmu_events_table *table = NULL;
char *cpuid = perf_pmu__getcpuid(pmu);
- int i;
+ size_t i;

/* on some platforms which uses cpus map, cpuid can be NULL for
* PMUs other than CORE PMUs.
@@ -968,7 +968,17 @@ const struct pmu_events_table *perf_pmu__find_events_table(struct perf_pmu *pmu)
}
}
free(cpuid);
- return table;
+ if (!pmu)
+ return table;
+
+ for (i = 0; i < table->num_pmus; i++) {
+ const struct pmu_table_entry *table_pmu = &table->pmus[i];
+ const char *pmu_name = &big_c_string[table_pmu->pmu_name.offset];
+
+ if (pmu__name_match(pmu, pmu_name))
+ return table;
+ }
+ return NULL;
}

const struct pmu_metrics_table *perf_pmu__find_metrics_table(struct perf_pmu *pmu)
diff --git a/tools/perf/tests/pmu-events.c b/tools/perf/tests/pmu-events.c
index 34f0de182fa9..4fcb84fd1f65 100644
--- a/tools/perf/tests/pmu-events.c
+++ b/tools/perf/tests/pmu-events.c
@@ -544,6 +544,7 @@ static int __test_core_pmu_event_aliases(char *pmu_name, int *count)
INIT_LIST_HEAD(&pmu->list);
pmu->name = strdup(pmu_name);

+ pmu->events_table = table;
pmu_add_cpu_aliases_table(pmu, table);

res = pmu_events_table__find_event(table, pmu, "bp_l1_btb_correct", NULL, NULL);
@@ -583,6 +584,7 @@ static int __test_uncore_pmu_event_aliases(struct perf_pmu_test_pmu *test_pmu)
events_table = find_core_events_table("testarch", "testcpu");
if (!events_table)
return -1;
+ pmu->events_table = events_table;
pmu_add_cpu_aliases_table(pmu, events_table);
pmu_add_sys_aliases(pmu);

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index a7d96e309843..dabae2019bd0 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -518,10 +518,10 @@ static int perf_pmu__new_alias(struct perf_pmu *pmu, int dirfd, const char *name
}
if (!pe) {
/* Update an event from sysfs with json data. */
- const struct pmu_events_table *table = perf_pmu__find_events_table(pmu);
-
- if (table)
- pmu_events_table__find_event(table, pmu, name, update_alias, alias);
+ if (pmu->events_table) {
+ pmu_events_table__find_event(pmu->events_table, pmu, name,
+ update_alias, alias);
+ }
}

/* Scan event and remove leading zeroes, spaces, newlines, some
@@ -871,13 +871,10 @@ void pmu_add_cpu_aliases_table(struct perf_pmu *pmu, const struct pmu_events_tab

static void pmu_add_cpu_aliases(struct perf_pmu *pmu)
{
- const struct pmu_events_table *table;
-
- table = perf_pmu__find_events_table(pmu);
- if (!table)
+ if (!pmu->events_table)
return;

- pmu_add_cpu_aliases_table(pmu, table);
+ pmu_add_cpu_aliases_table(pmu, pmu->events_table);
}

static int pmu_add_sys_aliases_iter_fn(const struct pmu_event *pe,
@@ -988,6 +985,7 @@ struct perf_pmu *perf_pmu__lookup(struct list_head *pmus, int dirfd, const char
if (pmu->is_uncore)
pmu->id = pmu_id(name);
pmu->max_precise = pmu_max_precise(dirfd, pmu);
+ pmu->events_table = perf_pmu__find_events_table(pmu);
pmu_add_cpu_aliases(pmu);
pmu_add_sys_aliases(pmu);
list_add_tail(&pmu->list, pmus);
@@ -1001,6 +999,7 @@ struct perf_pmu *perf_pmu__lookup(struct list_head *pmus, int dirfd, const char
return NULL;
}

+
/* Creates the PMU when sysfs scanning fails. */
struct perf_pmu *perf_pmu__create_placeholder_core_pmu(struct list_head *core_pmus)
{
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index 2b1730152bc0..6bf0fbde4e85 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -114,6 +114,10 @@ struct perf_pmu {
* from json events in pmu-events.c.
*/
struct list_head aliases;
+ /**
+ * @events_table: The events table for json events in pmu-events.c.
+ */
+ const struct pmu_events_table *events_table;
/** @caps_initialized: Has the list caps been initialized? */
bool caps_initialized;
/** @nr_caps: The length of the list caps. */
--
2.42.0.rc1.204.g551eb34607-goog