[PATCH 1/3] perf tools: Add callchain to ctf conversion

Geneviève Bastien
2017-07-27T18:31:06Z

The field perf_callchain, if available, is added to the sampling
events during the CTF conversion. It is an array of u64 values.
The perf_callchain_size field contains the size of the array.

It will allow the analysis of sampling data in trace visualization tools
like Trace Compass. Possible analyses with those data: dynamic
flamegraphs, correlation with other tracing data like a userspace trace.

Here follows a babeltrace CTF output of a trace with callchain:

$ babeltrace ./myctftrace
[17:38:45.672760285] (+?.?????????) cycles:ppp: { cpu_id = 0 }, { perf_ip = 0xFFFFFFFF81063EE4, perf_tid = 25841, perf_pid = 25774, perf_period = 1, perf_callchain_size = 7, perf_callchain = [ [0] = 0xFFFFFFFFFFFFFF80, [1] = 0xFFFFFFFF81063EE4, [2] = 0xFFFFFFFF8100C770, [3] = 0xFFFFFFFF81006EC6, [4] = 0xFFFFFFFF8118245E, [5] = 0xFFFFFFFF810A9224, [6] = 0xFFFFFFFF8164A4C6 ] }
[17:38:45.672777672] (+0.000017387) cycles:ppp: { cpu_id = 0 }, { perf_ip = 0xFFFFFFFF81063EE4, perf_tid = 25841, perf_pid = 25774, perf_period = 1, perf_callchain_size = 8, perf_callchain = [ [0] = 0xFFFFFFFFFFFFFF80, [1] = 0xFFFFFFFF81063EE4, [2] = 0xFFFFFFFF8100C770, [3] = 0xFFFFFFFF81006EC6, [4] = 0xFFFFFFFF8118245E, [5] = 0xFFFFFFFF810A9224, [6] = 0xFFFFFFFF8164A4C6, [7] = 0xFFFFFFFF8164ABAD ] }
[17:38:45.672786700] (+0.000009028) cycles:ppp: { cpu_id = 0 }, { perf_ip = 0xFFFFFFFF81063EE4, perf_tid = 25841, perf_pid = 25774, perf_period = 70, perf_callchain_size = 3, perf_callchain = [ [0] = 0xFFFFFFFFFFFFFF80, [1] = 0xFFFFFFFF81063EE4, [2] = 0xFFFFFFFF8100C770 ] }

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Julien Desfossez <jdesfossez@efficios.com>
Cc: Francis Deslauriers <francis.deslauriers@efficios.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Geneviève Bastien <gbastien@versatic.net>
Signed-off-by: Geneviève Bastien <gbastien@versatic.net>
---
tools/perf/util/data-convert-bt.c | 91 +++++++++++++++++++++++++++++++++++++++
1 file changed, 91 insertions(+)

diff --git a/tools/perf/util/data-convert-bt.c b/tools/perf/util/data-convert-bt.c
index 3149b70799fd..e99bccdb898d 100644
--- a/tools/perf/util/data-convert-bt.c
+++ b/tools/perf/util/data-convert-bt.c
@@ -506,6 +506,81 @@ add_bpf_output_values(struct bt_ctf_event_class *event_class,
return ret;
}

+static int
+add_callchain_output_values(struct bt_ctf_event_class *event_class,
+ struct bt_ctf_event *event,
+ struct ip_callchain *callchain)
+{
+ struct bt_ctf_field_type *len_type, *seq_type;
+ struct bt_ctf_field *len_field, *seq_field;
+ unsigned int nr_elements = callchain->nr;
+ unsigned int i;
+ int ret;
+
+ len_type = bt_ctf_event_class_get_field_by_name(
+ event_class, "perf_callchain_size");
+ len_field = bt_ctf_field_create(len_type);
+ if (!len_field) {
+ pr_err("failed to create 'perf_callchain_size' for callchain output event\n");
+ ret = -1;
+ goto put_len_type;
+ }
+
+ ret = bt_ctf_field_unsigned_integer_set_value(len_field, nr_elements);
+ if (ret) {
+ pr_err("failed to set field value for perf_callchain_size\n");
+ goto put_len_field;
+ }
+ ret = bt_ctf_event_set_payload(event, "perf_callchain_size", len_field);
+ if (ret) {
+ pr_err("failed to set payload to perf_callchain_size\n");
+ goto put_len_field;
+ }
+
+ seq_type = bt_ctf_event_class_get_field_by_name(
+ event_class, "perf_callchain");
+ seq_field = bt_ctf_field_create(seq_type);
+ if (!seq_field) {
+ pr_err("failed to create 'perf_callchain' for callchain output event\n");
+ ret = -1;
+ goto put_seq_type;
+ }
+
+ ret = bt_ctf_field_sequence_set_length(seq_field, len_field);
+ if (ret) {
+ pr_err("failed to set length of 'perf_callchain'\n");
+ goto put_seq_field;
+ }
+
+ for (i = 0; i < nr_elements; i++) {
+ struct bt_ctf_field *elem_field =
+ bt_ctf_field_sequence_get_field(seq_field, i);
+
+ ret = bt_ctf_field_unsigned_integer_set_value(elem_field,
+ ((u64 *)(callchain->ips))[i]);
+
+ bt_ctf_field_put(elem_field);
+ if (ret) {
+ pr_err("failed to set callchain[%d]\n", i);
+ goto put_seq_field;
+ }
+ }
+
+ ret = bt_ctf_event_set_payload(event, "perf_callchain", seq_field);
+ if (ret)
+ pr_err("failed to set payload for raw_data\n");
+
+put_seq_field:
+ bt_ctf_field_put(seq_field);
+put_seq_type:
+ bt_ctf_field_type_put(seq_type);
+put_len_field:
+ bt_ctf_field_put(len_field);
+put_len_type:
+ bt_ctf_field_type_put(len_type);
+ return ret;
+}
+
static int add_generic_values(struct ctf_writer *cw,
struct bt_ctf_event *event,
struct perf_evsel *evsel,
@@ -720,6 +795,7 @@ static int process_sample_event(struct perf_tool *tool,
struct bt_ctf_event_class *event_class;
struct bt_ctf_event *event;
int ret;
+ unsigned long type = evsel->attr.sample_type;

if (WARN_ONCE(!priv, "Failed to setup all events.\n"))
return 0;
@@ -751,6 +827,13 @@ static int process_sample_event(struct perf_tool *tool,
return -1;
}

+ if (type & PERF_SAMPLE_CALLCHAIN) {
+ ret = add_callchain_output_values(event_class,
+ event, sample->callchain);
+ if (ret)
+ return -1;
+ }
+
if (perf_evsel__is_bpf_output(evsel)) {
ret = add_bpf_output_values(event_class, event, sample);
if (ret)
@@ -1043,6 +1126,14 @@ static int add_generic_types(struct ctf_writer *cw, struct perf_evsel *evsel,
if (type & PERF_SAMPLE_TRANSACTION)
ADD_FIELD(event_class, cw->data.u64, "perf_transaction");

+ if (type & PERF_SAMPLE_CALLCHAIN) {
+ ADD_FIELD(event_class, cw->data.u32, "perf_callchain_size");
+ ADD_FIELD(event_class,
+ bt_ctf_field_type_sequence_create(
+ cw->data.u64_hex, "perf_callchain_size"),
+ "perf_callchain");
+ }
+
#undef ADD_FIELD
return 0;
}
--
2.13.3