From 306c17dead998aecc40e96f32df8b102ff19c7d1 Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Fri, 16 Sep 2022 11:41:30 -0700 Subject: [PATCH] perf stat: Fix cpu map index in bperf cgroup code [ Upstream commit 3da35231d9e4949c4ae40e3ce653e7c468455d55 ] 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: 0255571a16059c8e ("perf cpumap: Switch to using perf_cpu_map API") Signed-off-by: Namhyung Kim Cc: Adrian Hunter Cc: bpf@vger.kernel.org Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Song Liu Link: https://lore.kernel.org/r/20220916184132.1161506-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/util/bpf_counter_cgroup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/bpf_counter_cgroup.c b/tools/perf/util/bpf_counter_cgroup.c index 63b9db657442..97c69a249c6e 100644 --- a/tools/perf/util/bpf_counter_cgroup.c +++ b/tools/perf/util/bpf_counter_cgroup.c @@ -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, -- 2.45.0