bpftool: Display missed count for kprobe perf link

Adding 'missed' field to display missed counts for kprobes attached by perf event link, like: # bpftool link 5: perf_event prog 82 kprobe ffffffff815203e0 ksys_write 6: perf_event prog 83 kprobe ffffffff811d1e50 scheduler_tick missed 682217 # bpftool link -jp [{ "id": 5, "type": "perf_event", "prog_id": 82, "retprobe": false, "addr": 18446744071584220128, "func": "ksys_write", "offset": 0, "missed": 0 },{ "id": 6, "type": "perf_event", "prog_id": 83, "retprobe": false, "addr": 18446744071580753488, "func": "scheduler_tick", "offset": 0, "missed": 693469 } ] Signed-off-by: Jiri Olsa <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Reviewed-by: Quentin Monnet <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
libbpf · Oct 2, 2023 · 58046e2 · 58046e2
1 parent aa4f5fb
commit 58046e2
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/src/link.c b/src/link.c
@@ -302,6  302,7 @@ show_perf_event_kprobe_json(struct bpf_link_info *info, json_writer_t *wtr)
 	jsonw_string_field(wtr, "func",
 			   u64_to_ptr(info->perf_event.kprobe.func_name));
 	jsonw_uint_field(wtr, "offset", info->perf_event.kprobe.offset);
 	jsonw_uint_field(wtr, "missed", info->perf_event.kprobe.missed);
 }
 
 static void
@@ -686,6  687,8 @@ static void show_perf_event_kprobe_plain(struct bpf_link_info *info)
 	printf("%s", buf);
 	if (info->perf_event.kprobe.offset)
 		printf(" %#x", info->perf_event.kprobe.offset);
 	if (info->perf_event.kprobe.missed)
 		printf("  missed %llu", info->perf_event.kprobe.missed);
 	printf("  ");
 }