Re: [PATCH 06/11] perf data: Switch to multiple cpu stream files

[Wang Nan]

Hi Jiri,

Have you noticed that this patch causes a endianess problem?

Without this patch:

$ perf  data convert --to-ctf ./out.ctf
[ perf data convert: Converted 'perf.data' into CTF data './out.ctf' ]
[ perf data convert: Converted and wrote 0.000 MB (11 samples) ]

With this patch:

$ perf  data convert --to-ctf ./out.ctf
perf: event-types.c:1855: bt_ctf_field_type_set_native_byte_order: Assertion `byte_order == 1234 || byte_order == 4321' failed.
Aborted

I'll look into this problem if you haven't solved it yet. Please let me know if you have already
have some solutions.

Thank you.

On 2015/2/21 6:17, Jiri Olsa wrote:
> From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> 
> Currently we store the data into single data strea/file. The cpu
> if data is stored within the event sample. The lttng puts the CPU
> number that belongs to the event into the packet context instead
> into the event.
> 
> This patch makes sure that the trace produce by perf does look the
> same way. We now use one stream per-CPU. Having it all in one stream
> increased the total size of the resulting file. The test went from
> 416KiB (with perf_cpu event member) to 24MiB due to the required
> (and pointless) flush. With the per-cpu streams the total size went
> up to 588KiB.
> 
> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> Cc: David Ahern <dsahern@xxxxxxxxx>
> Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> Cc: Jeremie Galarneau <jgalar@xxxxxxxxxxxx>
> Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> Cc: Namhyung Kim <namhyung@xxxxxxxxx>
> Cc: Paul Mackerras <paulus@xxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> Cc: Tom Zanussi <tzanussi@xxxxxxxxx>
> Cc: Wang Nan <wangnan0@xxxxxxxxxx>
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> ---
>  tools/perf/util/data-convert-bt.c | 205 +++++++++++++++++++++++++++++++++-----
>  1 file changed, 181 insertions(+), 24 deletions(-)
> 
> diff --git a/tools/perf/util/data-convert-bt.c b/tools/perf/util/data-convert-bt.c
> index 6fa5c3ef336b..4bb769e081a8 100644
> --- a/tools/perf/util/data-convert-bt.c
> +++ b/tools/perf/util/data-convert-bt.c
> @@ -38,12 +38,20 @@ struct evsel_priv {
>  	struct bt_ctf_event_class *event_class;
>  };
>  
> +#define MAX_CPUS	4096
> +
> +struct ctf_stream {
> +	struct bt_ctf_stream *stream;
> +	int cpu;
> +};
> +
>  struct ctf_writer {
>  	/* writer primitives */
> -	struct bt_ctf_writer		*writer;
> -	struct bt_ctf_stream		*stream;
> -	struct bt_ctf_stream_class	*stream_class;
> -	struct bt_ctf_clock		*clock;
> +	struct bt_ctf_writer		 *writer;
> +	struct ctf_stream		**stream;
> +	int				  stream_cnt;
> +	struct bt_ctf_stream_class	 *stream_class;
> +	struct bt_ctf_clock		 *clock;
>  
>  	/* data types */
>  	union {
> @@ -346,12 +354,6 @@ static int add_generic_values(struct ctf_writer *cw,
>  			return -1;
>  	}
>  
> -	if (type & PERF_SAMPLE_CPU) {
> -		ret = value_set_u32(cw, event, "perf_cpu", sample->cpu);
> -		if (ret)
> -			return -1;
> -	}
> -
>  	if (type & PERF_SAMPLE_PERIOD) {
>  		ret = value_set_u64(cw, event, "perf_period", sample->period);
>  		if (ret)
> @@ -381,6 +383,113 @@ static int add_generic_values(struct ctf_writer *cw,
>  	return 0;
>  }
>  
> +static int ctf_stream__flush(struct ctf_stream *cs)
> +{
> +	int err = 0;
> +
> +	if (cs) {
> +		err = bt_ctf_stream_flush(cs->stream);
> +		if (err)
> +			pr_err("CTF stream %d flush failed\n", cs->cpu);
> +
> +		pr("Flush stream for cpu %d\n", cs->cpu);
> +	}
> +
> +	return err;
> +}
> +
> +static struct ctf_stream *ctf_stream__create(struct ctf_writer *cw, int cpu)
> +{
> +	struct ctf_stream *cs;
> +	struct bt_ctf_field *pkt_ctx   = NULL;
> +	struct bt_ctf_field *cpu_field = NULL;
> +	struct bt_ctf_stream *stream   = NULL;
> +	int ret;
> +
> +	cs = zalloc(sizeof(*cs));
> +	if (!cs) {
> +		pr_err("Failed to allocate ctf stream\n");
> +		return NULL;
> +	}
> +
> +	stream = bt_ctf_writer_create_stream(cw->writer, cw->stream_class);
> +	if (!stream) {
> +		pr_err("Failed to create CTF stream\n");
> +		goto out;
> +	}
> +
> +	pkt_ctx = bt_ctf_stream_get_packet_context(stream);
> +	if (!pkt_ctx) {
> +		pr_err("Failed to obtain packet context\n");
> +		goto out;
> +	}
> +
> +	cpu_field = bt_ctf_field_structure_get_field(pkt_ctx, "cpu_id");
> +	bt_ctf_field_put(pkt_ctx);
> +	if (!cpu_field) {
> +		pr_err("Failed to obtain cpu field\n");
> +		goto out;
> +	}
> +
> +	ret = bt_ctf_field_unsigned_integer_set_value(cpu_field, (u32) cpu);
> +	if (ret) {
> +		pr_err("Failed to update CPU number\n");
> +		goto out;
> +	}
> +
> +	bt_ctf_field_put(cpu_field);
> +
> +	cs->cpu    = cpu;
> +	cs->stream = stream;
> +	return cs;
> +
> +out:
> +	if (cpu_field)
> +		bt_ctf_field_put(cpu_field);
> +	if (stream)
> +		bt_ctf_stream_put(stream);
> +
> +	free(cs);
> +	return NULL;
> +}
> +
> +static void ctf_stream__delete(struct ctf_stream *cs)
> +{
> +	if (cs) {
> +		bt_ctf_stream_put(cs->stream);
> +		free(cs);
> +	}
> +}
> +
> +static struct ctf_stream *ctf_stream(struct ctf_writer *cw, int cpu)
> +{
> +	struct ctf_stream *cs = cw->stream[cpu];
> +
> +	if (!cs) {
> +		cs = ctf_stream__create(cw, cpu);
> +		cw->stream[cpu] = cs;
> +	}
> +
> +	return cs;
> +}
> +
> +static int get_sample_cpu(struct ctf_writer *cw, struct perf_sample *sample,
> +			  struct perf_evsel *evsel)
> +{
> +	int cpu = 0;
> +
> +	if (evsel->attr.sample_type & PERF_SAMPLE_CPU)
> +		cpu = sample->cpu;
> +
> +	if (cpu > cw->stream_cnt) {
> +		pr_err("Event was recorded for CPU %d, limit is at %d.\n",
> +			cpu, cw->stream_cnt);
> +		cpu = 0;
> +	}
> +
> +	return cpu;
> +}
> +
>  static int process_sample_event(struct perf_tool *tool,
>  				union perf_event *_event __maybe_unused,
>  				struct perf_sample *sample,
> @@ -390,6 +499,7 @@ static int process_sample_event(struct perf_tool *tool,
>  	struct convert *c = container_of(tool, struct convert, tool);
>  	struct evsel_priv *priv = evsel->priv;
>  	struct ctf_writer *cw = &c->writer;
> +	struct ctf_stream *cs;
>  	struct bt_ctf_event_class *event_class;
>  	struct bt_ctf_event *event;
>  	int ret;
> @@ -424,9 +534,12 @@ static int process_sample_event(struct perf_tool *tool,
>  			return -1;
>  	}
>  
> -	bt_ctf_stream_append_event(cw->stream, event);
> +	cs = ctf_stream(cw, get_sample_cpu(cw, sample, evsel));
> +	if (cs)
> +		bt_ctf_stream_append_event(cs->stream, event);
> +
>  	bt_ctf_event_put(event);
> -	return 0;
> +	return cs ? 0 : -1;
>  }
>  
>  static int add_tracepoint_fields_types(struct ctf_writer *cw,
> @@ -528,9 +641,6 @@ static int add_generic_types(struct ctf_writer *cw, struct perf_evsel *evsel,
>  	if (type & PERF_SAMPLE_STREAM_ID)
>  		ADD_FIELD(event_class, cw->data.u64, "perf_stream_id");
>  
> -	if (type & PERF_SAMPLE_CPU)
> -		ADD_FIELD(event_class, cw->data.u32, "perf_cpu");
> -
>  	if (type & PERF_SAMPLE_PERIOD)
>  		ADD_FIELD(event_class, cw->data.u64, "perf_period");
>  
> @@ -604,6 +714,39 @@ static int setup_events(struct ctf_writer *cw, struct perf_session *session)
>  	return 0;
>  }
>  
> +static int setup_streams(struct ctf_writer *cw, struct perf_session *session)
> +{
> +	struct ctf_stream **stream;
> +	struct perf_header *ph = &session->header;
> +	int ncpus;
> +
> +	/*
> +	 * Try to get the number of cpus used in the data file,
> +	 * if not present fallback to the MAX_CPUS.
> +	 */
> +	ncpus = ph->env.nr_cpus_avail ?: MAX_CPUS;
> +
> +	stream = zalloc(sizeof(*stream) * ncpus);
> +	if (!stream) {
> +		pr_err("Failed to allocate streams.\n");
> +		return -ENOMEM;
> +	}
> +
> +	cw->stream     = stream;
> +	cw->stream_cnt = ncpus;
> +	return 0;
> +}
> +
> +static void free_streams(struct ctf_writer *cw)
> +{
> +	int cpu;
> +
> +	for (cpu = 0; cpu < cw->stream_cnt; cpu++)
> +		ctf_stream__delete(cw->stream[cpu]);
> +
> +	free(cw->stream);
> +}
> +
>  static int ctf_writer__setup_env(struct ctf_writer *cw,
>  				 struct perf_session *session)
>  {
> @@ -713,7 +856,7 @@ static void ctf_writer__cleanup(struct ctf_writer *cw)
>  	ctf_writer__cleanup_data(cw);
>  
>  	bt_ctf_clock_put(cw->clock);
> -	bt_ctf_stream_put(cw->stream);
> +	free_streams(cw);
>  	bt_ctf_stream_class_put(cw->stream_class);
>  	bt_ctf_writer_put(cw->writer);
>  
> @@ -725,8 +868,9 @@ static int ctf_writer__init(struct ctf_writer *cw, const char *path)
>  {
>  	struct bt_ctf_writer		*writer;
>  	struct bt_ctf_stream_class	*stream_class;
> -	struct bt_ctf_stream		*stream;
>  	struct bt_ctf_clock		*clock;
> +	struct bt_ctf_field_type	*pkt_ctx_type;
> +	int				ret;
>  
>  	/* CTF writer */
>  	writer = bt_ctf_writer_create(path);
> @@ -767,14 +911,15 @@ static int ctf_writer__init(struct ctf_writer *cw, const char *path)
>  	if (ctf_writer__init_data(cw))
>  		goto err_cleanup;
>  
> -	/* CTF stream instance */
> -	stream = bt_ctf_writer_create_stream(writer, stream_class);
> -	if (!stream) {
> -		pr("Failed to create CTF stream.\n");
> +	/* Add cpu_id for packet context */
> +	pkt_ctx_type = bt_ctf_stream_class_get_packet_context_type(stream_class);
> +	if (!pkt_ctx_type)
>  		goto err_cleanup;
> -	}
>  
> -	cw->stream = stream;
> +	ret = bt_ctf_field_type_structure_add_field(pkt_ctx_type, cw->data.u32, "cpu_id");
> +	bt_ctf_field_type_put(pkt_ctx_type);
> +	if (ret)
> +		goto err_cleanup;
>  
>  	/* CTF clock writer setup */
>  	if (bt_ctf_writer_add_clock(writer, clock)) {
> @@ -791,6 +936,14 @@ err:
>  	return -1;
>  }
>  
> +static void ctf_writer__flush_streams(struct ctf_writer *cw)
> +{
> +	int cpu;
> +
> +	for (cpu = 0; cpu < cw->stream_cnt; cpu++)
> +		ctf_stream__flush(cw->stream[cpu]);
> +}
> +
>  int bt_convert__perf2ctf(const char *input, const char *path)
>  {
>  	struct perf_session *session;
> @@ -833,9 +986,13 @@ int bt_convert__perf2ctf(const char *input, const char *path)
>  	if (setup_events(cw, session))
>  		goto free_session;
>  
> +	if (setup_streams(cw, session))
> +		goto free_session;
> +
>  	err = perf_session__process_events(session, &c.tool);
>  	if (!err)
> -		err = bt_ctf_stream_flush(cw->stream);
> +		ctf_writer__flush_streams(cw);
> +
>  
>  	fprintf(stderr,
>  		"[ perf data convert: Converted '%s' into CTF data '%s' ]\n",
> 


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/