[PATCH] perf evlist: Fix 'perf record -C xx' failed issue

From: Chunxin Zang
Date: Tue Mar 19 2024 - 04:40:56 EST


The cpu has 8 performance-cores and 8 efficient-cores on my pc.
0-15 are performance-cores
16-23 are 8 efficient-cores

When I run "perf record -C xxx", the command fails if xxx all belong to
performance cores or efficient cores

The results are as follows

# perf record -C 12
WARNING: A requested CPU in '12' is not supported by PMU 'cpu_atom' (CPUs 16-23) for event 'cycles:P'
Error:
The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (cpu_atom/cycles:P/).
/bin/dmesg | grep -i perf may provide additional information.

# perf record -C 14-17
WARNING: A requested CPU in '14-17' is not supported by PMU 'cpu_atom' (CPUs 16-23) for event 'cycles:P'
WARNING: A requested CPU in '14-17' is not supported by PMU 'cpu_core' (CPUs 0-15) for event 'cycles:P'
^C[ perf record: Woken up 1 times to write data ]

The reason is that the cpu_map of 'cpu_atom'-evsel is empty, causing
the sys_perf_event_open() result to fail.

Signed-off-by: Chunxin Zang <spring.cxz@xxxxxxxxx>
Reviewed-by: Chen Yang <yangchen11@xxxxxxxxxxx>
---
tools/perf/util/evlist.c | 23 ++++++++++++++++-------
1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 55a300a0977b..4dd0d0980606 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -2499,7 +2499,7 @@ void evlist__check_mem_load_aux(struct evlist *evlist)
void evlist__warn_user_requested_cpus(struct evlist *evlist, const char *cpu_list)
{
struct perf_cpu_map *user_requested_cpus;
- struct evsel *pos;
+ struct evsel *pos, *tmp;

if (!cpu_list)
return;
@@ -2508,18 +2508,27 @@ void evlist__warn_user_requested_cpus(struct evlist *evlist, const char *cpu_lis
if (!user_requested_cpus)
return;

- evlist__for_each_entry(evlist, pos) {
+ evlist__for_each_entry_safe(evlist, tmp, 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];
+ if (!intersect) {
+ evlist__remove(evlist, pos);
+ evsel__delete(pos);
+ continue;
+ }
+
+ if (!perf_cpu_map__is_subset(user_requested_cpus, intersect)) {
+ char buf_test[128];
+ char buf_intersect[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));
+ cpu_map__snprint(to_test, buf_test, sizeof(buf_test));
+ cpu_map__snprint(intersect, buf_intersect, sizeof(buf_intersect));
+ pr_warning("WARNING: A requested CPU '%s' in '%s' is not supported by "
+ "PMU '%s' (CPUs %s) for event '%s'\n", buf_intersect, cpu_list,
+ pmu ? pmu->name : "cpu", buf_test, evsel__name(pos));
}
perf_cpu_map__put(intersect);
}
--
2.34.1