[PATCH 6.9 125/374] perf pmu: Count sys and cpuid JSON events separately

Greg Kroah-Hartman
2024-06-06T14:09:19Z

From: Ian Rogers <irogers@google.com>

[ Upstream commit d9c5f5f94c2d356fdf3503f7fcaf254512bc032d ]

Sys events are eagerly loaded as each event has a compat option that may
mean the event is or isn't associated with the PMU.

These shouldn't be counted as loaded_json_events as that is used for
JSON events matching the CPUID that may or may not have been loaded. The
mismatch causes issues on ARM64 that uses sys events.

Fixes: e6ff1eed3584362d ("perf pmu: Lazily add JSON events")
Closes: https://lore.kernel.org/lkml/20240510024729.1075732-1-justin.he@arm.com/
Reported-by: Jia He <justin.he@arm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240511003601.2666907-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/perf/util/pmu.c | 70 ++++++++++++++++++++++++++++++-------------
tools/perf/util/pmu.h | 6 ++--
2 files changed, 53 insertions(+), 23 deletions(-)

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index feab54606a995..cc349d9cb0f9f 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -36,6 +36,18 @@ struct perf_pmu perf_pmu__fake = {

#define UNIT_MAX_LEN 31 /* max length for event unit name */

+enum event_source {
+ /* An event loaded from /sys/devices/<pmu>/events. */
+ EVENT_SRC_SYSFS,
+ /* An event loaded from a CPUID matched json file. */
+ EVENT_SRC_CPU_JSON,
+ /*
+ * An event loaded from a /sys/devices/<pmu>/identifier matched json
+ * file.
+ */
+ EVENT_SRC_SYS_JSON,
+};
+
/**
* struct perf_pmu_alias - An event either read from sysfs or builtin in
* pmu-events.c, created by parsing the pmu-events json files.
@@ -521,7 +533,7 @@ static int update_alias(const struct pmu_event *pe,

static int perf_pmu__new_alias(struct perf_pmu *pmu, const char *name,
const char *desc, const char *val, FILE *val_fd,
- const struct pmu_event *pe)
+ const struct pmu_event *pe, enum event_source src)
{
struct perf_pmu_alias *alias;
int ret;
@@ -573,25 +585,30 @@ static int perf_pmu__new_alias(struct perf_pmu *pmu, const char *name,
}
snprintf(alias->unit, sizeof(alias->unit), "%s", unit);
}
- if (!pe) {
- /* Update an event from sysfs with json data. */
- struct update_alias_data data = {
- .pmu = pmu,
- .alias = alias,
- };
-
+ switch (src) {
+ default:
+ case EVENT_SRC_SYSFS:
alias->from_sysfs = true;
if (pmu->events_table) {
+ /* Update an event from sysfs with json data. */
+ struct update_alias_data data = {
+ .pmu = pmu,
+ .alias = alias,
+ };
if (pmu_events_table__find_event(pmu->events_table, pmu, name,
update_alias, &data) == 0)
- pmu->loaded_json_aliases++;
+ pmu->cpu_json_aliases++;
}
- }
-
- if (!pe)
pmu->sysfs_aliases++;
- else
- pmu->loaded_json_aliases++;
+ break;
+ case EVENT_SRC_CPU_JSON:
+ pmu->cpu_json_aliases++;
+ break;
+ case EVENT_SRC_SYS_JSON:
+ pmu->sys_json_aliases++;
+ break;
+
+ }
list_add_tail(&alias->list, &pmu->aliases);
return 0;
}
@@ -667,7 +684,8 @@ static int pmu_aliases_parse(struct perf_pmu *pmu)
}

if (perf_pmu__new_alias(pmu, name, /*desc=*/ NULL,
- /*val=*/ NULL, file, /*pe=*/ NULL) < 0)
+ /*val=*/ NULL, file, /*pe=*/ NULL,
+ EVENT_SRC_SYSFS) < 0)
pr_debug("Cannot set up %s\n", name);
fclose(file);
}
@@ -921,7 +939,8 @@ static int pmu_add_cpu_aliases_map_callback(const struct pmu_event *pe,
{
struct perf_pmu *pmu = vdata;

- perf_pmu__new_alias(pmu, pe->name, pe->desc, pe->event, /*val_fd=*/ NULL, pe);
+ perf_pmu__new_alias(pmu, pe->name, pe->desc, pe->event, /*val_fd=*/ NULL,
+ pe, EVENT_SRC_CPU_JSON);
return 0;
}

@@ -956,13 +975,14 @@ static int pmu_add_sys_aliases_iter_fn(const struct pmu_event *pe,
return 0;

if (pmu_uncore_alias_match(pe->pmu, pmu->name) &&
- pmu_uncore_identifier_match(pe->compat, pmu->id)) {
+ pmu_uncore_identifier_match(pe->compat, pmu->id)) {
perf_pmu__new_alias(pmu,
pe->name,
pe->desc,
pe->event,
/*val_fd=*/ NULL,
- pe);
+ pe,
+ EVENT_SRC_SYS_JSON);
}

return 0;
@@ -1056,6 +1076,12 @@ struct perf_pmu *perf_pmu__lookup(struct list_head *pmus, int dirfd, const char
pmu->max_precise = pmu_max_precise(dirfd, pmu);
pmu->alias_name = pmu_find_alias_name(pmu, dirfd);
pmu->events_table = perf_pmu__find_events_table(pmu);
+ /*
+ * Load the sys json events/aliases when loading the PMU as each event
+ * may have a different compat regular expression. We therefore can't
+ * know the number of sys json events/aliases without computing the
+ * regular expressions for them all.
+ */
pmu_add_sys_aliases(pmu);
list_add_tail(&pmu->list, pmus);

@@ -1654,12 +1680,14 @@ size_t perf_pmu__num_events(struct perf_pmu *pmu)
size_t nr;

pmu_aliases_parse(pmu);
- nr = pmu->sysfs_aliases;
+ nr = pmu->sysfs_aliases + pmu->sys_json_aliases;;

if (pmu->cpu_aliases_added)
- nr += pmu->loaded_json_aliases;
+ nr += pmu->cpu_json_aliases;
else if (pmu->events_table)
- nr += pmu_events_table__num_events(pmu->events_table, pmu) - pmu->loaded_json_aliases;
+ nr += pmu_events_table__num_events(pmu->events_table, pmu) - pmu->cpu_json_aliases;
+ else
+ assert(pmu->cpu_json_aliases == 0);

return pmu->selectable ? nr + 1 : nr;
}
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index 2430083b151d0..77c59ebc05261 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -123,8 +123,10 @@ struct perf_pmu {
const struct pmu_events_table *events_table;
/** @sysfs_aliases: Number of sysfs aliases loaded. */
uint32_t sysfs_aliases;
- /** @sysfs_aliases: Number of json event aliases loaded. */
- uint32_t loaded_json_aliases;
+ /** @cpu_json_aliases: Number of json event aliases loaded specific to the CPUID. */
+ uint32_t cpu_json_aliases;
+ /** @sys_json_aliases: Number of json event aliases loaded matching the PMU's identifier. */
+ uint32_t sys_json_aliases;
/** @sysfs_aliases_loaded: Are sysfs aliases loaded from disk? */
bool sysfs_aliases_loaded;
/**
--
2.43.0