Re: [PATCH] monitor: trace qmp_send_response

[Markus Armbruster]

Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> writes:

> 05.02.2021 10:56, Markus Armbruster wrote:
>> Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> writes:
>> 
>>> Add a useful counterpart for trace_handle_qmp_command for debugging
>>> libvirt guests.
>>>
>>> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>>> ---
>>>   monitor/qmp.c        | 6 ++++++
>>>   monitor/trace-events | 1 +
>>>   2 files changed, 7 insertions(+)
>>>
>>> diff --git a/monitor/qmp.c b/monitor/qmp.c
>>> index 8f91af32be..772b9e7b30 100644
>>> --- a/monitor/qmp.c
>>> +++ b/monitor/qmp.c
>>> @@ -111,6 +111,12 @@ void qmp_send_response(MonitorQMP *mon, const QDict 
>>> *rsp)
>>>       const QObject *data = QOBJECT(rsp);
>>>       GString *json;
>>>   +    if (trace_event_get_state_backends(TRACE_QMP_SEND_RESPONSE))
>>> {
>>> +        json = qobject_to_json(data);
>>> +        trace_qmp_send_response(mon, json->str);
>>> +        g_string_free(json, true);
>>> +    }
>>> +
>>>       json = qobject_to_json_pretty(data, mon->pretty);
>>>       assert(json != NULL);
>>>   diff --git a/monitor/trace-events b/monitor/trace-events
>>> index 0365ac4d99..12f0576c7b 100644
>>> --- a/monitor/trace-events
>>> +++ b/monitor/trace-events
>>> @@ -13,3 +13,4 @@ monitor_suspend(void *ptr, int cnt) "mon %p: %d"
>>>   monitor_qmp_cmd_in_band(const char *id) "%s"
>>>   monitor_qmp_cmd_out_of_band(const char *id) "%s"
>>>   handle_qmp_command(void *mon, const char *req) "mon %p req: %s"
>>> +qmp_send_response(void *mon, const char *req) "mon %p req: %s"
>> A slightly lazier version of this just landed in commit f680405f45
>> "qmp:
>> Add more tracepoints".  The difference is yours ignores mon->pretty for
>> tracing.
>> Thoughts?
>> 
>
> Ah, missed this, great. Then, nothing to do.
>
> In our environment (I'm not sure who do it libvirt, or other our tool) 
> different query- commands are called periodically and their output is big 
> enough, so I decided to trace json in oneline.. Still better is developing a 
> way to not trace some qmp commands and their output.

Feel free to add features you find useful on top.