Commit 3812d298 authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo
Browse files

perf record: Add finished init event 



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.

Committer notes:

Add entry about PERF_RECORD_FINISHED_INIT to
tools/perf/Documentation/perf.data-file-format.txt.

Committer testing:

Before:

  # perf report -D | grep FINISHED
  0 0x5910 [0x8]: PERF_RECORD_FINISHED_ROUND
    FINISHED_ROUND events:          1  ( 0.5%)
  #

After:

  # perf record -- sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.020 MB perf.data (7 samples) ]
  # perf report -D | grep FINISHED
  0 0x5068 [0x8]: PERF_RECORD_FINISHED_INIT: unhandled!
  0 0x5390 [0x8]: PERF_RECORD_FINISHED_ROUND
    FINISHED_ROUND events:          1  ( 0.5%)
     FINISHED_INIT events:          1  ( 0.5%)
  #

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Acked-by: default avatarIan Rogers <irogers@google.com>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20220610113316.6682-5-adrian.hunter@intel.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 61110883

tools/lib/perf/include/perf/event.h

+1 −0
Original line number Diff line number Diff line
@@ -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

};

tools/perf/Documentation/perf.data-file-format.txt

+10 −0
Original line number Diff line number Diff line
@@ -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.

tools/perf/builtin-inject.c

+1 −0
Original line number Diff line number Diff line
@@ -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,

		},

tools/perf/builtin-record.c

+27 −0
Original line number Diff line number Diff line
@@ -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);

tools/perf/util/event.c

+1 −0
Original line number Diff line number Diff line
@@ -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)