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

From: Arnaldo Carvalho de Melo
Date: Thu Jun 23 2022 - 09:46:26 EST

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.

- Arnaldo

> 0 0x4fc8 [0x48]: PERF_RECORD_KSYMBOL addr ffffffffc10d0650 len 255 type 1 flags 0x0 name bpf_prog_ee0e253c78993a24
>
> 0x5010@xxxxxxxxx [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@xxxxxxxxx [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@xxxxxxxxx [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@xxxxxxxxx [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@xxxxxxxxx [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@xxxxxxxxx>
> > ---
> > 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