[PATCH] perf: add event name to json output

[Oleg Latin]

After converting perf.data to json it missing event name entry.

In perf script output it is clear that events have different types:

    $ perf script -F -ip
    ...
    dd 130321 [001] 10282.698083:     117995       cycles:
    dd 130321 [001] 10282.698091:     225856 instructions:
    ...

But json output lack of this information and it hard to distinguish
different event types:

    ...
    {
        "timestamp": 10282698083472,
        "pid": 130321,
        "tid": 130321,
        "comm": "dd",
        "callchain": [
            {
                "ip": "0xffffffff901f4cd5",
                "symbol": "syscall_exit_to_user_mode",
                "dso": "[kernel.kallsyms]"
            }
        ]
    },
    {
        "timestamp": 10282698091328,
        "pid": 130321,
        "tid": 130321,
        "comm": "dd",
        "callchain": [
            {
                "ip": "0x7fb7f0c271e7",
                "symbol": "__GI___libc_write",
                "dso": "libc-2.31.so"
            }
        ]
    },
    ...

This patch adds event name entry to resulting json.

Signed-off-by: Oleg Latin <oleglatin@xxxxxxxxxxxxxx>
---
 tools/perf/util/data-convert-json.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/perf/util/data-convert-json.c b/tools/perf/util/data-convert-json.c
index b0e3d69c6835..72aaf6babc22 100644
--- a/tools/perf/util/data-convert-json.c
+++ b/tools/perf/util/data-convert-json.c
@@ -168,6 +168,9 @@ static int process_sample_event(struct perf_tool *tool,
 	output_json_key_format(out, true, 3, "pid", "%i", al.thread->pid_);
 	output_json_key_format(out, true, 3, "tid", "%i", al.thread->tid);
 
+	if (evsel->name)
+		output_json_key_string(out, true, 3, "event", evsel->name);
+
 	if (al.cpu >= 0)
 		output_json_key_format(out, true, 3, "cpu", "%i", al.cpu);
 
-- 
2.25.1