[PATCH net-next 4/4] bpf: add a test case for helper bpf_perf_prog_read_time

[Yonghong Song]

The bpf sample program trace_event is enhanced to use the new
helper to print out enabled/running time.

Signed-off-by: Yonghong Song <y...@fb.com>
---
 samples/bpf/trace_event_kern.c            | 5 +++++
 tools/testing/selftests/bpf/bpf_helpers.h | 3 +++
 2 files changed, 8 insertions(+)

diff --git a/samples/bpf/trace_event_kern.c b/samples/bpf/trace_event_kern.c
index 41b6115..f372660 100644
--- a/samples/bpf/trace_event_kern.c
+++ b/samples/bpf/trace_event_kern.c
@@ -37,8 +37,10 @@ struct bpf_map_def SEC("maps") stackmap = {
 SEC("perf_event")
 int bpf_prog1(struct bpf_perf_event_data *ctx)
 {
+       char time_fmt[] = "Time Enabled: %lld, Time Running: %lld";
        char fmt[] = "CPU-%d period %lld ip %llx";
        u32 cpu = bpf_get_smp_processor_id();
+       struct bpf_perf_time time_buf;
        struct key_t key;
        u64 *val, one = 1;
 
@@ -54,6 +56,9 @@ int bpf_prog1(struct bpf_perf_event_data *ctx)
                return 0;
        }
 
+       bpf_perf_prog_read_time(ctx, (void *)&time_buf, sizeof(struct 
bpf_perf_time));
+       bpf_trace_printk(time_fmt, sizeof(time_fmt), time_buf.enabled, 
time_buf.running);
+
        val = bpf_map_lookup_elem(&counts, &key);
        if (val)
                (*val)++;
diff --git a/tools/testing/selftests/bpf/bpf_helpers.h 
b/tools/testing/selftests/bpf/bpf_helpers.h
index fe41852..ddad690 100644
--- a/tools/testing/selftests/bpf/bpf_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_helpers.h
@@ -74,6 +74,9 @@ static int (*bpf_perf_read_counter_time)(void *map, unsigned 
long long flags,
                                       void *counter_time_buf,
                                       unsigned int buf_size) =
        (void *) BPF_FUNC_perf_read_counter_time;
+static int (*bpf_perf_prog_read_time)(void *ctx, void *time_buf,
+                                     unsigned int size) =
+       (void *) BPF_FUNC_perf_prog_read_time;
 
 
 /* llvm builtin functions that eBPF C program may use to
-- 
2.9.5