@@ -95,7 +95,7 @@ static int bperf_load_program(struct evlist *evlist)
perf_cpu_map__for_each_cpu(cpu, i, evlist->core.all_cpus) {
link = bpf_program__attach_perf_event(skel->progs.on_cgrp_switch,
- FD(cgrp_switch, cpu.cpu));
+ FD(cgrp_switch, i));
if (IS_ERR(link)) {
pr_err("Failed to attach cgroup program\n");
err = PTR_ERR(link);
@@ -123,7 +123,7 @@ static int bperf_load_program(struct evlist *evlist)
map_fd = bpf_map__fd(skel->maps.events);
perf_cpu_map__for_each_cpu(cpu, j, evlist->core.all_cpus) {
- int fd = FD(evsel, cpu.cpu);
+ int fd = FD(evsel, j);
__u32 idx = evsel->core.idx * total_cpus + cpu.cpu;
err = bpf_map_update_elem(map_fd, &idx, &fd,
The previous cpu map introduced a bug in the bperf cgroup counter. This results in a failure when user gives a partial cpu map starting from non-zero. $ sudo ./perf stat -C 1-2 --bpf-counters --for-each-cgroup ^. sleep 1 libbpf: prog 'on_cgrp_switch': failed to create BPF link for perf_event FD 0: -9 (Bad file descriptor) Failed to attach cgroup program To get the FD of an evsel, it should use a map index not the CPU number. Fixes: 0255571a1605 ("perf cpumap: Switch to using perf_cpu_map API") Signed-off-by: Namhyung Kim <namhyung@kernel.org> --- tools/perf/util/bpf_counter_cgroup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)