Re: [PATCH 4/5] perf record: Add finished init event

Adrian Hunter
2022-06-23T19:26:18Z

On 23/06/22 16:55, Arnaldo Carvalho de Melo wrote:
> Em Thu, Jun 23, 2022 at 10:46:18AM -0300, Arnaldo Carvalho de Melo escreveu:
>> Em Thu, Jun 23, 2022 at 10:41:31AM -0300, Arnaldo Carvalho de Melo escreveu:
>>> Em Fri, Jun 10, 2022 at 02:33:15PM +0300, Adrian Hunter escreveu:
>>>> In preparation for recording sideband events in a virtual machine guest so
>>>> that they can be injected into a host perf.data file.
>>>>
>>>> This is needed to enable injecting events after the initial synthesized
>>>> user events (that have an all zero id sample) but before regular events.
>>>
>>> Humm, can't we consider the first FINISHED_ROUND as a good enough marker
>>> for this?
>>
>> Nope, synthesize_flush() may be called multiple times during the
>> initialization (the synthesizing of PERF_RECORD_ events for pre-existing
>> threads)...
>>
>> I'm reapplying this patch.
>
> And add this, please check:
>
> diff --git a/tools/perf/Documentation/perf.data-file-format.txt b/tools/perf/Documentation/perf.data-file-format.txt
> index f56d0e0fbff6ef66..bc9f0aa113d8b6d4 100644
> --- a/tools/perf/Documentation/perf.data-file-format.txt
> +++ b/tools/perf/Documentation/perf.data-file-format.txt
> @@ -607,6 +607,16 @@ struct compressed_event {
> char data[];
> };
>
> + PERF_RECORD_FINISHED_INIT = 82,
> +
> +Marks the end of records for the system, pre-existing threads in system wide
> +sessions, etc. Those are the ones prefixed PERF_RECORD_USER_*.
> +
> +This is used, for instance, to 'perf inject' events after init and before
> +regular events, those emitted by the kernel, to support combining guest and
> +host records.
> +
> +
> The header is followed by compressed data frame that can be decompressed
> into array of perf trace records. The size of the entire compressed event
> record including the header is limited by the max value of header.size.
> ⬢[acme@toolbox perf]$

That's great! Thank you!

>
>
> - Arnaldo
>
>> - Arnaldo
>>
>>> 0 0x4fc8 [0x48]: PERF_RECORD_KSYMBOL addr ffffffffc10d0650 len 255 type 1 flags 0x0 name bpf_prog_ee0e253c78993a24
>>>
>>> 0x5010@perf.data [0x28]: event: 18
>>> .
>>> . ... raw event: size 40 bytes
>>> . 0000: 12 00 00 00 00 00 28 00 01 00 00 00 28 00 00 00 ......(.....(...
>>> . 0010: ee 0e 25 3c 78 99 3a 24 00 00 00 00 00 00 00 00 ..%<x.:$........
>>> . 0020: 00 00 00 00 00 00 00 00 ........
>>>
>>> 0 0x5010 [0x28]: PERF_RECORD_BPF_EVENT type 1, flags 0, id 40
>>>
>>> 0x5038@perf.data [0x30]: event: 3
>>> .
>>> . ... raw event: size 48 bytes
>>> . 0000: 03 00 00 00 00 00 30 00 3a 5d 00 00 3a 5d 00 00 ......0.:]..:]..
>>> . 0010: 70 65 72 66 2d 65 78 65 63 00 00 00 00 00 00 00 perf-exec.......
>>> . 0020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
>>>
>>> 0 0x5038 [0x30]: PERF_RECORD_COMM: perf-exec:23866/23866
>>>
>>> 0x5068@perf.data [0x8]: event: 82
>>> .
>>> . ... raw event: size 8 bytes
>>> . 0000: 52 00 00 00 00 00 08 00 R.......
>>>
>>> 0 0x5068 [0x8]: PERF_RECORD_FINISHED_INIT: unhandled!
>>>
>>> 0x5390@perf.data [0x8]: event: 68
>>> .
>>> . ... raw event: size 8 bytes
>>> . 0000: 44 00 00 00 00 00 08 00 D.......
>>>
>>> 0 0x5390 [0x8]: PERF_RECORD_FINISHED_ROUND
>>>
>>> 0x5070@perf.data [0x28]: event: 9
>>> .
>>> . ... raw event: size 40 bytes
>>> . 0000: 09 00 00 00 01 00 28 00 50 b5 16 a7 ff ff ff ff ......(.P.......
>>> . 0010: 3a 5d 00 00 3a 5d 00 00 54 90 f5 bf 52 01 00 00 :]..:]..T...R...
>>> . 0020: 01 00 00 00 00 00 00 00 ........
>>>
>>> 1454919487572 0x5070 [0x28]: PERF_RECORD_SAMPLE(IP, 0x1): 23866/23866: 0xffffffffa716b550 period: 1 addr: 0
>>>
>>>
>>>> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
>>>> ---
>>>> tools/lib/perf/include/perf/event.h | 1 +
>>>> tools/perf/builtin-inject.c | 1 +
>>>> tools/perf/builtin-record.c | 27 +++++++++++++++++++++++++++
>>>> tools/perf/util/event.c | 1 +
>>>> tools/perf/util/session.c | 4 ++++
>>>> tools/perf/util/tool.h | 3 ++-
>>>> 6 files changed, 36 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/tools/lib/perf/include/perf/event.h b/tools/lib/perf/include/perf/event.h
>>>> index e7758707cadd..9f7ca070da87 100644
>>>> --- a/tools/lib/perf/include/perf/event.h
>>>> +++ b/tools/lib/perf/include/perf/event.h
>>>> @@ -389,6 +389,7 @@ enum perf_user_event_type { /* above any possible kernel type */
>>>> PERF_RECORD_TIME_CONV = 79,
>>>> PERF_RECORD_HEADER_FEATURE = 80,
>>>> PERF_RECORD_COMPRESSED = 81,
>>>> + PERF_RECORD_FINISHED_INIT = 82,
>>>> PERF_RECORD_HEADER_MAX
>>>> };
>>>>
>>>> diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
>>>> index a75bf11585b5..42e2918fd1cc 100644
>>>> --- a/tools/perf/builtin-inject.c
>>>> +++ b/tools/perf/builtin-inject.c
>>>> @@ -1059,6 +1059,7 @@ int cmd_inject(int argc, const char **argv)
>>>> .stat = perf_event__repipe_op2_synth,
>>>> .stat_round = perf_event__repipe_op2_synth,
>>>> .feature = perf_event__repipe_op2_synth,
>>>> + .finished_init = perf_event__repipe_op2_synth,
>>>> .compressed = perf_event__repipe_op4_synth,
>>>> .auxtrace = perf_event__repipe_auxtrace,
>>>> },
>>>> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
>>>> index 40dca1fba4e3..cf5c5379ceaa 100644
>>>> --- a/tools/perf/builtin-record.c
>>>> +++ b/tools/perf/builtin-record.c
>>>> @@ -1388,6 +1388,11 @@ static struct perf_event_header finished_round_event = {
>>>> .type = PERF_RECORD_FINISHED_ROUND,
>>>> };
>>>>
>>>> +static struct perf_event_header finished_init_event = {
>>>> + .size = sizeof(struct perf_event_header),
>>>> + .type = PERF_RECORD_FINISHED_INIT,
>>>> +};
>>>> +
>>>> static void record__adjust_affinity(struct record *rec, struct mmap *map)
>>>> {
>>>> if (rec->opts.affinity != PERF_AFFINITY_SYS &&
>>>> @@ -1696,6 +1701,14 @@ static int record__synthesize_workload(struct record *rec, bool tail)
>>>> return err;
>>>> }
>>>>
>>>> +static int write_finished_init(struct record *rec, bool tail)
>>>> +{
>>>> + if (rec->opts.tail_synthesize != tail)
>>>> + return 0;
>>>> +
>>>> + return record__write(rec, NULL, &finished_init_event, sizeof(finished_init_event));
>>>> +}
>>>> +
>>>> static int record__synthesize(struct record *rec, bool tail);
>>>>
>>>> static int
>>>> @@ -1710,6 +1723,8 @@ record__switch_output(struct record *rec, bool at_exit)
>>>>
>>>> record__aio_mmap_read_sync(rec);
>>>>
>>>> + write_finished_init(rec, true);
>>>> +
>>>> record__synthesize(rec, true);
>>>> if (target__none(&rec->opts.target))
>>>> record__synthesize_workload(rec, true);
>>>> @@ -1764,6 +1779,7 @@ record__switch_output(struct record *rec, bool at_exit)
>>>> */
>>>> if (target__none(&rec->opts.target))
>>>> record__synthesize_workload(rec, false);
>>>> + write_finished_init(rec, false);
>>>> }
>>>> return fd;
>>>> }
>>>> @@ -2419,6 +2435,15 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
>>>> trigger_ready(&auxtrace_snapshot_trigger);
>>>> trigger_ready(&switch_output_trigger);
>>>> perf_hooks__invoke_record_start();
>>>> +
>>>> + /*
>>>> + * Must write FINISHED_INIT so it will be seen after all other
>>>> + * synthesized user events, but before any regular events.
>>>> + */
>>>> + err = write_finished_init(rec, false);
>>>> + if (err < 0)
>>>> + goto out_child;
>>>> +
>>>> for (;;) {
>>>> unsigned long long hits = thread->samples;
>>>>
>>>> @@ -2563,6 +2588,8 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
>>>> fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n",
>>>> record__waking(rec));
>>>>
>>>> + write_finished_init(rec, true);
>>>> +
>>>> if (target__none(&rec->opts.target))
>>>> record__synthesize_workload(rec, true);
>>>>
>>>> diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
>>>> index 0476bb3a4188..1fa14598b916 100644
>>>> --- a/tools/perf/util/event.c
>>>> +++ b/tools/perf/util/event.c
>>>> @@ -76,6 +76,7 @@ static const char *perf_event__names[] = {
>>>> [PERF_RECORD_TIME_CONV] = "TIME_CONV",
>>>> [PERF_RECORD_HEADER_FEATURE] = "FEATURE",
>>>> [PERF_RECORD_COMPRESSED] = "COMPRESSED",
>>>> + [PERF_RECORD_FINISHED_INIT] = "FINISHED_INIT",
>>>> };
>>>>
>>>> const char *perf_event__name(unsigned int id)
>>>> diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
>>>> index 0aa818977d2b..37f833c3c81b 100644
>>>> --- a/tools/perf/util/session.c
>>>> +++ b/tools/perf/util/session.c
>>>> @@ -562,6 +562,8 @@ void perf_tool__fill_defaults(struct perf_tool *tool)
>>>> tool->feature = process_event_op2_stub;
>>>> if (tool->compressed == NULL)
>>>> tool->compressed = perf_session__process_compressed_event;
>>>> + if (tool->finished_init == NULL)
>>>> + tool->finished_init = process_event_op2_stub;
>>>> }
>>>>
>>>> static void swap_sample_id_all(union perf_event *event, void *data)
>>>> @@ -1706,6 +1708,8 @@ static s64 perf_session__process_user_event(struct perf_session *session,
>>>> if (err)
>>>> dump_event(session->evlist, event, file_offset, &sample, file_path);
>>>> return err;
>>>> + case PERF_RECORD_FINISHED_INIT:
>>>> + return tool->finished_init(session, event);
>>>> default:
>>>> return -EINVAL;
>>>> }
>>>> diff --git a/tools/perf/util/tool.h b/tools/perf/util/tool.h
>>>> index f2352dba1875..c957fb849ac6 100644
>>>> --- a/tools/perf/util/tool.h
>>>> +++ b/tools/perf/util/tool.h
>>>> @@ -76,7 +76,8 @@ struct perf_tool {
>>>> stat_config,
>>>> stat,
>>>> stat_round,
>>>> - feature;
>>>> + feature,
>>>> + finished_init;
>>>> event_op4 compressed;
>>>> event_op3 auxtrace;
>>>> bool ordered_events;
>>>> --
>>>> 2.25.1
>>>
>>> --
>>>
>>> - Arnaldo
>>
>> --
>>
>> - Arnaldo
>