From: Andrii Nakryiko andriin@fb.com
commit 91cbdf740a476cf2c744169bf407de2e3ac1f3cf upstream.
Fix up perf_buffer.c selftest to take into account offline/missing CPUs.
Fixes: ee5cf82ce04a ("selftests/bpf: test perf buffer API") Signed-off-by: Andrii Nakryiko andriin@fb.com Signed-off-by: Alexei Starovoitov ast@kernel.org Link: https://lore.kernel.org/bpf/20191212013621.1691858-1-andriin@fb.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- tools/testing/selftests/bpf/prog_tests/perf_buffer.c | 29 +++++++++++++++---- 1 file changed, 24 insertions(+), 5 deletions(-)
--- a/tools/testing/selftests/bpf/prog_tests/perf_buffer.c +++ b/tools/testing/selftests/bpf/prog_tests/perf_buffer.c @@ -4,6 +4,7 @@ #include <sched.h> #include <sys/socket.h> #include <test_progs.h> +#include "libbpf_internal.h"
static void on_sample(void *ctx, int cpu, void *data, __u32 size) { @@ -19,7 +20,7 @@ static void on_sample(void *ctx, int cpu
void test_perf_buffer(void) { - int err, prog_fd, nr_cpus, i, duration = 0; + int err, prog_fd, on_len, nr_on_cpus = 0, nr_cpus, i, duration = 0; const char *prog_name = "kprobe/sys_nanosleep"; const char *file = "./test_perf_buffer.o"; struct perf_buffer_opts pb_opts = {}; @@ -29,15 +30,27 @@ void test_perf_buffer(void) struct bpf_object *obj; struct perf_buffer *pb; struct bpf_link *link; + bool *online;
nr_cpus = libbpf_num_possible_cpus(); if (CHECK(nr_cpus < 0, "nr_cpus", "err %d\n", nr_cpus)) return;
+ err = parse_cpu_mask_file("/sys/devices/system/cpu/online", + &online, &on_len); + if (CHECK(err, "nr_on_cpus", "err %d\n", err)) + return; + + for (i = 0; i < on_len; i++) + if (online[i]) + nr_on_cpus++; + /* load program */ err = bpf_prog_load(file, BPF_PROG_TYPE_KPROBE, &obj, &prog_fd); - if (CHECK(err, "obj_load", "err %d errno %d\n", err, errno)) - return; + if (CHECK(err, "obj_load", "err %d errno %d\n", err, errno)) { + obj = NULL; + goto out_close; + }
prog = bpf_object__find_program_by_title(obj, prog_name); if (CHECK(!prog, "find_probe", "prog '%s' not found\n", prog_name)) @@ -64,6 +77,11 @@ void test_perf_buffer(void) /* trigger kprobe on every CPU */ CPU_ZERO(&cpu_seen); for (i = 0; i < nr_cpus; i++) { + if (i >= on_len || !online[i]) { + printf("skipping offline CPU #%d\n", i); + continue; + } + CPU_ZERO(&cpu_set); CPU_SET(i, &cpu_set);
@@ -81,8 +99,8 @@ void test_perf_buffer(void) if (CHECK(err < 0, "perf_buffer__poll", "err %d\n", err)) goto out_free_pb;
- if (CHECK(CPU_COUNT(&cpu_seen) != nr_cpus, "seen_cpu_cnt", - "expect %d, seen %d\n", nr_cpus, CPU_COUNT(&cpu_seen))) + if (CHECK(CPU_COUNT(&cpu_seen) != nr_on_cpus, "seen_cpu_cnt", + "expect %d, seen %d\n", nr_on_cpus, CPU_COUNT(&cpu_seen))) goto out_free_pb;
out_free_pb: @@ -91,4 +109,5 @@ out_detach: bpf_link__destroy(link); out_close: bpf_object__close(obj); + free(online); }