[PATCH] perf evlist: Fix the warning logic about warn_user_request_cpu

From: Chunxin Zang
Date: Mon Mar 18 2024 - 08:12:22 EST


The old logic in evlist__warn_user_requested_cpus incorrectly output
the warning message when I run 'perf record -C xxx' command on my
context(the cpu has 8 performance-cores and 8 efficient-cores.).

The old warning like this:
# perf record -C 17
WARNING: A requested CPU in '17' is not supported by PMU 'cpu_core' (CPUs 0-15) for event 'cycles:P'
# perf record -C 14
WARNING: A requested CPU in '14' is not supported by PMU 'cpu_atom' (CPUs 16-23) for event 'cycles:P'
# perf record -C 14-17
WARNING: A requested CPU in '15-16' is not supported by PMU 'cpu_atom' (CPUs 16-23) for event 'cycles:P'
WARNING: A requested CPU in '15-16' is not supported by PMU 'cpu_core' (CPUs 0-15) for event 'cycles:P'

After patching, the warning is as follows
# perf record -C 17
WARNING: A requested CPU '17' in '17' is not supported by PMU 'cpu_atom' (CPUs 16-23) for event 'cycles:P'
# perf record -C 14
WARNING: A requested CPU '14' in '14' is not supported by PMU 'cpu_core' (CPUs 0-15) for event 'cycles:P'
# perf record -C 15-18
WARNING: A requested CPU '16-18' in '15-18' is not supported by PMU 'cpu_atom' (CPUs 16-23) for event 'cycles:P'
WARNING: A requested CPU '15' in '15-18' is not supported by PMU 'cpu_core' (CPUs 0-15) for event 'cycles:P'

Signed-off-by: Chunxin Zang <spring.cxz@xxxxxxxxx>
Reviewed-by: Chen Yang <yangchen11@xxxxxxxxxxx>
---
tools/perf/util/evlist.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 55a300a0977b..82fee2e29966 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -2514,12 +2514,16 @@ void evlist__warn_user_requested_cpus(struct evlist *evlist, const char *cpu_lis

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));
+ if (intersect && perf_cpu_map__is_subset(user_requested_cpus, intersect)) {
+ char buf_test[128];
+ char buf_intersect[128];
+
+ 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