bpf: add a test case for helper bpf_perf_event_read_value

The bpf sample program tracex6 is enhanced to use the new
helper to read enabled/running time as well.

Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Yonghong Song
2017-10-05 09:19:21 -07:00
committed by David S. Miller
parent 908432ca84
commit 020a32d958
4 changed files with 43 additions and 2 deletions

View File

@@ -22,6 +22,7 @@
static void check_on_cpu(int cpu, struct perf_event_attr *attr)
{
struct bpf_perf_event_value value2;
int pmu_fd, error = 0;
cpu_set_t set;
__u64 value;
@@ -46,8 +47,18 @@ static void check_on_cpu(int cpu, struct perf_event_attr *attr)
fprintf(stderr, "Value missing for CPU %d\n", cpu);
error = 1;
goto on_exit;
} else {
fprintf(stderr, "CPU %d: %llu\n", cpu, value);
}
/* The above bpf_map_lookup_elem should trigger the second kprobe */
if (bpf_map_lookup_elem(map_fd[2], &cpu, &value2)) {
fprintf(stderr, "Value2 missing for CPU %d\n", cpu);
error = 1;
goto on_exit;
} else {
fprintf(stderr, "CPU %d: counter: %llu, enabled: %llu, running: %llu\n", cpu,
value2.counter, value2.enabled, value2.running);
}
fprintf(stderr, "CPU %d: %llu\n", cpu, value);
on_exit:
assert(bpf_map_delete_elem(map_fd[0], &cpu) == 0 || error);