diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2018-10-21 02:09:28 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2018-10-20 23:13:32 -0700 |
| commit | 3dca21156b5f809510e8c3efe7f1046e27242e3d (patch) | |
| tree | ee60aebfc20747a4df2532951263c3f64858f802 /tools/bpf | |
| parent | 84430d4232c36cb858564374f839d233fd6f623a (diff) | |
bpf, libbpf: simplify and cleanup perf ring buffer walk
Simplify bpf_perf_event_read_simple() a bit and fix up some minor
things along the way: the return code in the header is not of type
int but enum bpf_perf_event_ret instead. Once callback indicated
to break the loop walking event data, it also needs to be consumed
in data_tail since it has been processed already.
Moreover, bpf_perf_event_print_t callback should avoid void * as
we actually get a pointer to struct perf_event_header and thus
applications can make use of container_of() to have type checks.
The walk also doesn't have to use modulo op since the ring size is
required to be power of two.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/bpf')
| -rw-r--r-- | tools/bpf/bpftool/map_perf_ring.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/tools/bpf/bpftool/map_perf_ring.c b/tools/bpf/bpftool/map_perf_ring.c index 6d41323be291..bdaf4062e26e 100644 --- a/tools/bpf/bpftool/map_perf_ring.c +++ b/tools/bpf/bpftool/map_perf_ring.c @@ -50,15 +50,17 @@ static void int_exit(int signo) stop = true; } -static enum bpf_perf_event_ret print_bpf_output(void *event, void *priv) +static enum bpf_perf_event_ret +print_bpf_output(struct perf_event_header *event, void *private_data) { - struct event_ring_info *ring = priv; - struct perf_event_sample *e = event; + struct perf_event_sample *e = container_of(event, struct perf_event_sample, + header); + struct event_ring_info *ring = private_data; struct { struct perf_event_header header; __u64 id; __u64 lost; - } *lost = event; + } *lost = (typeof(lost))event; if (json_output) { jsonw_start_object(json_wtr); |