From 81b9cf8028a17bdbdaa0da80b735b32150d4e89e Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Thu, 5 Oct 2017 09:19:23 -0700 Subject: bpf: add a test case for helper bpf_perf_prog_read_value The bpf sample program trace_event is enhanced to use the new helper to print out enabled/running time. Signed-off-by: Yonghong Song Acked-by: Alexei Starovoitov Acked-by: Daniel Borkmann Signed-off-by: David S. Miller --- samples/bpf/trace_event_kern.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'samples/bpf/trace_event_kern.c') diff --git a/samples/bpf/trace_event_kern.c b/samples/bpf/trace_event_kern.c index 41b6115a32eb..a77a583d94d4 100644 --- a/samples/bpf/trace_event_kern.c +++ b/samples/bpf/trace_event_kern.c @@ -37,10 +37,14 @@ struct bpf_map_def SEC("maps") stackmap = { SEC("perf_event") int bpf_prog1(struct bpf_perf_event_data *ctx) { + char time_fmt1[] = "Time Enabled: %llu, Time Running: %llu"; + char time_fmt2[] = "Get Time Failed, ErrCode: %d"; char fmt[] = "CPU-%d period %lld ip %llx"; u32 cpu = bpf_get_smp_processor_id(); + struct bpf_perf_event_value value_buf; struct key_t key; u64 *val, one = 1; + int ret; if (ctx->sample_period < 10000) /* ignore warmup */ @@ -54,6 +58,12 @@ int bpf_prog1(struct bpf_perf_event_data *ctx) return 0; } + ret = bpf_perf_prog_read_value(ctx, (void *)&value_buf, sizeof(struct bpf_perf_event_value)); + if (!ret) + bpf_trace_printk(time_fmt1, sizeof(time_fmt1), value_buf.enabled, value_buf.running); + else + bpf_trace_printk(time_fmt2, sizeof(time_fmt2), ret); + val = bpf_map_lookup_elem(&counts, &key); if (val) (*val)++; -- cgit v1.2.3-59-g8ed1b