[PATCH v4 12/35] perf tools: Warn if no user requested CPUs match PMU's CPUs

Ian Rogers
2023-05-26T21:55:30Z

In commit 1d3351e631fc ("perf tools: Enable on a list of CPUs for hybrid")
perf on hybrid will warn if a user requested CPU doesn't match the PMU
of the given event but only for hybrid PMUs. Make the logic generic
for all PMUs and remove the hybrid logic.

Warn if a CPU is requested that isn't present/offline for events not
on the core. Warn if a CPU is requested for a core PMU, but the CPU
isn't within the cpu map of that PMU.

For example on a 16 (0-15) CPU system:
```
$ perf stat -e imc_free_running/data_read/,cycles -C 16 true
WARNING: A requested CPU in '16' is not supported by PMU 'uncore_imc_free_running_1' (CPUs 0-15) for event 'imc_free_running/data_read/'
WARNING: A requested CPU in '16' is not supported by PMU 'uncore_imc_free_running_0' (CPUs 0-15) for event 'imc_free_running/data_read/'
WARNING: A requested CPU in '16' is not supported by PMU 'cpu' (CPUs 0-15) for event 'cycles'

Performance counter stats for 'CPU(s) 16':

<not supported> MiB imc_free_running/data_read/
<not supported> cycles

0.000575312 seconds time elapsed
```

Remove evlist__fix_hybrid_cpus that previously produced the warnings
and also perf_pmu__cpus_match that worked with evlist__fix_hybrid_cpus
to change CPU maps for hybrid CPUs, something that is no longer
necessary as CPU map propagation properly intersects user requested
CPUs with the core PMU's CPU map.

Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
---
tools/perf/builtin-record.c | 6 +--
tools/perf/builtin-stat.c | 5 +--
tools/perf/util/evlist-hybrid.c | 74 ---------------------------------
tools/perf/util/evlist-hybrid.h | 1 -
tools/perf/util/evlist.c | 39 +++++++++++++++++
tools/perf/util/evlist.h | 2 +
tools/perf/util/pmu.c | 33 ---------------
tools/perf/util/pmu.h | 4 --
8 files changed, 43 insertions(+), 121 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index d152ab04a209..88f7b4241153 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -4198,11 +4198,7 @@ int cmd_record(int argc, const char **argv)
/* Enable ignoring missing threads when -u/-p option is defined. */
rec->opts.ignore_missing_thread = rec->opts.target.uid != UINT_MAX || rec->opts.target.pid;

- if (evlist__fix_hybrid_cpus(rec->evlist, rec->opts.target.cpu_list)) {
- pr_err("failed to use cpu list %s\n",
- rec->opts.target.cpu_list);
- goto out;
- }
+ evlist__warn_user_requested_cpus(rec->evlist, rec->opts.target.cpu_list);

if (callchain_param.enabled && callchain_param.record_mode == CALLCHAIN_FP)
arch__add_leaf_frame_record_opts(&rec->opts);
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index c70cb0990661..04c9289e6ceb 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -2462,10 +2462,7 @@ int cmd_stat(int argc, const char **argv)
}
}

- if (evlist__fix_hybrid_cpus(evsel_list, target.cpu_list)) {
- pr_err("failed to use cpu list %s\n", target.cpu_list);
- goto out;
- }
+ evlist__warn_user_requested_cpus(evsel_list, target.cpu_list);

if (evlist__create_maps(evsel_list, &target) < 0) {
if (target__has_task(&target)) {
diff --git a/tools/perf/util/evlist-hybrid.c b/tools/perf/util/evlist-hybrid.c
index 57f02beef023..db3f5fbdebe1 100644
--- a/tools/perf/util/evlist-hybrid.c
+++ b/tools/perf/util/evlist-hybrid.c
@@ -86,77 +86,3 @@ bool evlist__has_hybrid(struct evlist *evlist)

return false;
}
-
-int evlist__fix_hybrid_cpus(struct evlist *evlist, const char *cpu_list)
-{
- struct perf_cpu_map *cpus;
- struct evsel *evsel, *tmp;
- struct perf_pmu *pmu;
- int ret, unmatched_count = 0, events_nr = 0;
-
- if (!perf_pmu__has_hybrid() || !cpu_list)
- return 0;
-
- cpus = perf_cpu_map__new(cpu_list);
- if (!cpus)
- return -1;
-
- /*
- * The evsels are created with hybrid pmu's cpus. But now we
- * need to check and adjust the cpus of evsel by cpu_list because
- * cpu_list may cause conflicts with cpus of evsel. For example,
- * cpus of evsel is cpu0-7, but the cpu_list is cpu6-8, we need
- * to adjust the cpus of evsel to cpu6-7. And then propatate maps
- * in evlist__create_maps().
- */
- evlist__for_each_entry_safe(evlist, tmp, evsel) {
- struct perf_cpu_map *matched_cpus, *unmatched_cpus;
- char buf1[128], buf2[128];
-
- pmu = perf_pmu__find_hybrid_pmu(evsel->pmu_name);
- if (!pmu)
- continue;
-
- ret = perf_pmu__cpus_match(pmu, cpus, &matched_cpus,
- &unmatched_cpus);
- if (ret)
- goto out;
-
- events_nr++;
-
- if (perf_cpu_map__nr(matched_cpus) > 0 &&
- (perf_cpu_map__nr(unmatched_cpus) > 0 ||
- perf_cpu_map__nr(matched_cpus) < perf_cpu_map__nr(cpus) ||
- perf_cpu_map__nr(matched_cpus) < perf_cpu_map__nr(pmu->cpus))) {
- perf_cpu_map__put(evsel->core.cpus);
- perf_cpu_map__put(evsel->core.own_cpus);
- evsel->core.cpus = perf_cpu_map__get(matched_cpus);
- evsel->core.own_cpus = perf_cpu_map__get(matched_cpus);
-
- if (perf_cpu_map__nr(unmatched_cpus) > 0) {
- cpu_map__snprint(matched_cpus, buf1, sizeof(buf1));
- pr_warning("WARNING: use %s in '%s' for '%s', skip other cpus in list.\n",
- buf1, pmu->name, evsel->name);
- }
- }
-
- if (perf_cpu_map__nr(matched_cpus) == 0) {
- evlist__remove(evlist, evsel);
- evsel__delete(evsel);
-
- cpu_map__snprint(cpus, buf1, sizeof(buf1));
- cpu_map__snprint(pmu->cpus, buf2, sizeof(buf2));
- pr_warning("WARNING: %s isn't a '%s', please use a CPU list in the '%s' range (%s)\n",
- buf1, pmu->name, pmu->name, buf2);
- unmatched_count++;
- }
-
- perf_cpu_map__put(matched_cpus);
- perf_cpu_map__put(unmatched_cpus);
- }
- if (events_nr)
- ret = (unmatched_count == events_nr) ? -1 : 0;
-out:
- perf_cpu_map__put(cpus);
- return ret;
-}
diff --git a/tools/perf/util/evlist-hybrid.h b/tools/perf/util/evlist-hybrid.h
index aacdb1b0f948..19f74b4c340a 100644
--- a/tools/perf/util/evlist-hybrid.h
+++ b/tools/perf/util/evlist-hybrid.h
@@ -10,6 +10,5 @@
int evlist__add_default_hybrid(struct evlist *evlist, bool precise);
void evlist__warn_hybrid_group(struct evlist *evlist);
bool evlist__has_hybrid(struct evlist *evlist);
-int evlist__fix_hybrid_cpus(struct evlist *evlist, const char *cpu_list);

#endif /* __PERF_EVLIST_HYBRID_H */
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 2e2c3509bec3..9dfa977193b3 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -2465,3 +2465,42 @@ void evlist__check_mem_load_aux(struct evlist *evlist)
}
}
}
+
+/**
+ * evlist__warn_user_requested_cpus() - Check each evsel against requested CPUs
+ * and warn if the user CPU list is inapplicable for the event's PMU's
+ * CPUs. Not core PMUs list a CPU in sysfs, but this may be overwritten by a
+ * user requested CPU and so any online CPU is applicable. Core PMUs handle
+ * events on the CPUs in their list and otherwise the event isn't supported.
+ * @evlist: The list of events being checked.
+ * @cpu_list: The user provided list of CPUs.
+ */
+void evlist__warn_user_requested_cpus(struct evlist *evlist, const char *cpu_list)
+{
+ struct perf_cpu_map *user_requested_cpus;
+ struct evsel *pos;
+
+ if (!cpu_list)
+ return;
+
+ user_requested_cpus = perf_cpu_map__new(cpu_list);
+ if (!user_requested_cpus)
+ return;
+
+ evlist__for_each_entry(evlist, pos) {
+ struct perf_cpu_map *intersect, *to_test;
+ const struct perf_pmu *pmu = evsel__find_pmu(pos);
+
+ to_test = pmu && pmu->is_core ? pmu->cpus : cpu_map__online();
+ intersect = perf_cpu_map__intersect(to_test, user_requested_cpus);
+ if (!perf_cpu_map__equal(intersect, user_requested_cpus)) {
+ char buf[128];
+
+ cpu_map__snprint(to_test, buf, sizeof(buf));
+ pr_warning("WARNING: A requested CPU in '%s' is not supported by PMU '%s' (CPUs %s) for event '%s'\n",
+ cpu_list, pmu ? pmu->name : "cpu", buf, evsel__name(pos));
+ }
+ perf_cpu_map__put(intersect);
+ }
+ perf_cpu_map__put(user_requested_cpus);
+}
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index e7e5540cc970..5e7ff44f3043 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -447,4 +447,6 @@ struct evsel *evlist__find_evsel(struct evlist *evlist, int idx);

int evlist__scnprintf_evsels(struct evlist *evlist, size_t size, char *bf);
void evlist__check_mem_load_aux(struct evlist *evlist);
+void evlist__warn_user_requested_cpus(struct evlist *evlist, const char *cpu_list);
+
#endif /* __PERF_EVLIST_H */
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index d992f5242d99..cd94abe7a87a 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -2046,39 +2046,6 @@ int perf_pmu__match(char *pattern, char *name, char *tok)
return 0;
}

-int perf_pmu__cpus_match(struct perf_pmu *pmu, struct perf_cpu_map *cpus,
- struct perf_cpu_map **mcpus_ptr,
- struct perf_cpu_map **ucpus_ptr)
-{
- struct perf_cpu_map *pmu_cpus = pmu->cpus;
- struct perf_cpu_map *matched_cpus, *unmatched_cpus;
- struct perf_cpu cpu;
- int i, matched_nr = 0, unmatched_nr = 0;
-
- matched_cpus = perf_cpu_map__default_new();
- if (!matched_cpus)
- return -1;
-
- unmatched_cpus = perf_cpu_map__default_new();
- if (!unmatched_cpus) {
- perf_cpu_map__put(matched_cpus);
- return -1;
- }
-
- perf_cpu_map__for_each_cpu(cpu, i, cpus) {
- if (!perf_cpu_map__has(pmu_cpus, cpu))
- RC_CHK_ACCESS(unmatched_cpus)->map[unmatched_nr++] = cpu;
- else
- RC_CHK_ACCESS(matched_cpus)->map[matched_nr++] = cpu;
- }
-
- perf_cpu_map__set_nr(unmatched_cpus, unmatched_nr);
- perf_cpu_map__set_nr(matched_cpus, matched_nr);
- *mcpus_ptr = matched_cpus;
- *ucpus_ptr = unmatched_cpus;
- return 0;
-}
-
double __weak perf_pmu__cpu_slots_per_cycle(void)
{
return NAN;
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index 96236a79c6fd..af10d137e2b5 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -265,10 +265,6 @@ void perf_pmu__warn_invalid_formats(struct perf_pmu *pmu);
bool perf_pmu__has_hybrid(void);
int perf_pmu__match(char *pattern, char *name, char *tok);

-int perf_pmu__cpus_match(struct perf_pmu *pmu, struct perf_cpu_map *cpus,
- struct perf_cpu_map **mcpus_ptr,
- struct perf_cpu_map **ucpus_ptr);
-
char *pmu_find_real_name(const char *name);
char *pmu_find_alias_name(const char *name);
double perf_pmu__cpu_slots_per_cycle(void);
--
2.41.0.rc0.172.g3f132b7071-goog